Sunday, August 13, 2017

Have You EVER...

When I became a Permanent Resident within the United States (commonly called a 'Green Card'), among the multitude of paperwork I had to fill out form I-485 which asks a ton of questions about your home country, your parents, your kids, your spouse, your job, and then about your past actions. Most of them start with "Have you EVER" then go on to ask such questions as "worked in the United States without authorization?" or "violated the terms and conditions of your non-immigrant status?", and include some rather interesting catch-alls like "committed a crime of any kind (even if you were not arrested, cited, charged with, or tried for that crime)?" which would be likely to cover about 99% of the entire population. (Fortunately the Supreme Court ruled this year that the speeding ticket you forgot about won't get you arrested and deported). Then you get the serious crime questions like "knowingly aided and abetted... in trafficking persons for commercial sex acts or slavery?" and "engaged in money laundering?" (Not even specifically Russian money!). 

Further down there's a section that asks the following:

Have you ever been a member of a group in which you used any weapon against another person or threatened to?

and then (paraphrased)

Are you a Nazi?

Ticking 'yes' to either of those would likely see you called in for a more in-depth interview or denial of the green card. If you look here, you can see that of those people "denaturalized" as US Citizens, most of them were for being a Nazi. So given I had to do all that to get in to this country, I'm just wondering why a whole bunch of guys can get together, intimidate everyone they can (especially minority groups), claim oppression, give Nazi salutes and cry "Heil Trump", run cars into crowds of pedestrians, and generally "act like brown-shirts" and the President of the United States will not condemn them?

Staying quiet at times like this supports the aggressor. Actions like we saw this weekend were inevitable given the encouragement that's been given to them by this administration. It will only get worse if left to fester. There are Nazi-adjacent people in the White House* - Bannon, Gorka, Miller. They are writing policy for this country, such as immigration. By both action and inaction, this administration is encouraging this.

To those of you who voted for this travesty - was it really worth this to get that Supreme Court seat, and are you really going to continue staying quiet about things like this in the hope you get a tax cut passed?

What's the price of your soul?

We all know this is wrong. It's disgusting. It's not the best of what America can stand for. It's not what 400,000 Americans died in WWII for. When I became a citizen of this country, I confirmed I wasn't a Nazi, that I didn't join groups to threaten others. It seems immigrants are held to a higher standard than the natives, and clearly than the current President.

Nearly seven months ago this administration made it clear what it was going to do. I felt then that staying quiet was being complicit in what they intend to make this country, I'm all the more sure of these words now:

Everyone who knows right from wrong has to work together no matter what tribe we used to think we belonged to. 

We can't be divided, we have to stand up for the weakest and easiest targets, no exceptions.

Support those who stand for what's right, condemn those who promote and enable what's wrong. 

There's no hiding anymore, no more abdication of responsibility. This is where we learn who we really are. Don't disappoint your children.

*updated from the original. I changed 'literal Nazis' to 'Nazi-adjacent'. Partly because I did something that frustrates me and used 'literal' when it's not quite. Gorka, a British born naturalized US Citizen, is a member of an organization with a Nazi history, and three US Senators have requested the DHS review his immigration process in the USA due to exactly the process I outline above - that being a member of such a group is grounds for denial of entry. Miller is reported to be a friend and protege of Richard Spencer, a prominent white supremacist, and the original Travel Ban from January this year was authored by him. Both in the past have denied these claims, though they do draw a lot of support and praise from them. Bannon ran Breitbart.com, which described itself as "home of the alt-right (white supremacists)". Previously, they have been described as "white supremacist adjacent", however given that they are comfortable using the extreme right wing and neo-Nazi groups to gain populist support for their agenda, and have by their actions (like the Travel Ban, or removal of federal funding for groups that oppose white supremacists) emboldened them, I'm not inclined to give them leeway. So was that some hyperbola? Yes, but after the events of this last weekend, I'm not willing to cut any slack to anyone not running from this right now. I'd rather be wrong about this and apologize later than say nothing as it festers and grows.

Sunday, July 30, 2017

MEMS Gyroscopes, Smartphones, and Ultrasound

This morning I was reading an article on Ars Technica (great tech website if you don't already read it) about the use of "sonic guns" to disrupt the operation of electronics and gadgets like drones. Here's a simple demonstration video of this happening.


As you can see the toy robot, which balances due to the gryoscopes in it, is quickly confused by the incident sound and ends up moving, then falling over. Why does this happen?

MEMS gyroscopes are Micro-Electrical-Mechanical Systems, essentially a very small structure that's often made by the same processes used to build computer chips, that has combined electrical and mechanical behaviors that are useful to us. In the case of a MEMS gyro, it leads to motion that creates an electrical signal which can be processed to determine rotation. These structures are small enough to be packaged into something smaller than your fingernail, and so can be fitted into compact spaces and consumer goods. Here's a video of a very simple MEMS gyro oscillating.



An image below from UC Davis MEMSLab shows how one small device can detect rotation in all three axes.


You can see that each sensing mode here has at least one "resonant frequency" at which the device naturally oscillates, which means it is very very sensitive to those frequencies. Like finding the right pitch for a glass, you can actually break them by causing them to vibrate at that frequency. Some work here, here, and here shows in more academic detail how the MEMS gyros can be rendered ineffective by ultrasound above around 100 dB. Sound is, after all, just a vibration at a particular frequency - match that sound to the resonant frequency of the gyro and it will play havoc with it.

Here's a drone showing the effect of ultrasound on its behaviour - notice that the transducers used to generate the ultrasound look like Murata devices, very similar in appearance to what uBeam look to be using in their transmitters. (I appreciate the safety precautions this researcher took!)


What this all seems to be pointing to is that high powered ultrasound in the environment can disrupt the activities of more and more of our devices such as drones - what happens if they fly through a high power ultrasound beam? Do they veer off and hit someone? And the smartphones we all use today? Those phones have multiple MEMS sensors in them, and the gyro is what allows you to play games just by tilting your phone. What happens when you direct ultrasound at levels far greater than 100 dB towards a smartphone? The manufacturers know, they spend a lot of time making sure that nothing in the phone vibrates at frequencies that disrupt their operation, but I'm not sure I've seen a study that's been made public.

Those may seem like simple examples, but there are safety considerations. What happens if a safety related system, such as positioning in a vehicle, is disrupted by high power ultrasound? Who is responsible for that? Cars and larger objects can usually shield the gyro to insulate the sound from it, but what about size and weight sensitive devices like smartphones?

If the videos above give an indication, then truly ubiquitous high power ultrasound in the environment is going to be disruptive in more ways than one. Just as well no-one is likely to try to put such loud ultrasound devices out there en-masse.

Dunkirk

Movie review: Dunkirk

Basically - go see it. Great movie. No - fantastic movie. I've found Chris Nolan to be hit or miss - always beautifully filmed, but there are often plot holes you can drive a bus through that most people seem to miss because it all looks so good, and so much is thrown at you that you're overloaded. Inception and The Prestige are the two worst examples of this (so bad I've watched them twice..) while Interstellar has ridiculously awful science it pretends to adhere to, until halfway through it shifts to a "love conquers all" mode and rapidly descends to a giant cauldron of liquid poo in which it revels. Memento gets it right, sticking with a single theme and follows it through, while the first two Batman films are just brilliant (followed by an entertaining but not-as-good third).

Nolan loves to play with time in his films - Inception with its layers and ticking clock, Interstellar with the time dilation due (and ticking clock), Memento and the forward/backward storyline. He does the same in Dunkirk, with three storylines of a week, a day, and an hour in the lives of several Dunkirk participants, all intersecting in parts as they grow closer and closer together - and all through it, a ticking clock (literally) as the soldiers desperately try to get home.

I don't often get drawn in to films, but I found myself tense throughout, and Nolan manages to bring in a lot of tension as you sit on edge waiting for the next thing to go wrong. It's an exhausting film. More though, it gets over the utter powerlessness of almost all the participants, that they're simply statistics and at some point people are going to die, no matter their skill or preparation. This isn't an Arnie action film where the hero saves the day, this is about the horrors of war and how small and insignificant each person is, but also the intense bravery of many of these men in ways that no-one ever would know.

There's a Marie-Claire contributor who has been talking about how it's just a film glorifying war for men. Yeah, this glorifies war like Trainspotting glorifies taking drugs. It's hideous from nearly 80 years away.

As we exited the film, my wife recounted some stories of her grandfather, who was at Dunkirk. She had interviewed him as part of a school project. He was a remarkable man, I met him when he was in his early 90's, and I would have guessed he was in his 60's. Born in 1912, grew up in a children's home, joined the army when 18, served until the end of WWII, started a welding business then sold it and retired at 65 - got bored and started another one at 67 and ran it until he was 89. He didn't talk about what he did in the war, he even gave all his medals to a local museum to the horror of his family, as he thought no-one would care.

As part of this interview, he described running through the streets towards the beaches at Dunkirk, with men feet away from him being shot dead, and waiting for the evacuation. He was told he was brave but he said he never felt brave, all he did was try to survive. And that, in the end, was much of the point of the film, that these men survived and then later went back to fight again, that these seemingly small acts of what they couldn't see as bravery, mattered.

It also made me think of my wife's great uncle. He was on board the Royal Oak, a British battleship sunk by the Germans at the onset of WWII. Of the ~1200 crew, 833 were killed when it was torpedoed in Scapa Flow at the naval base in Orkney - her uncle, Billy, was one of the men killed. He was 16. Like the Arizona at Pearl Harbor, this site is now a war grave, and we were allowed to scatter the ashes of Billy's sister there. She never got over the loss of her brother. Another young man who tried to do what he could and serve, yet died almost the moment it began. The film reminded me that great feats aren't required to be a hero, that simply volunteering for a role that puts you in harms way for a greater good does that.

All that, so well filmed, and perfectly acted by every one of them, especially Tom Hardy. Never overplayed, just done right.

I'm not sure I've seen a film that conveys the horror and randomness of war, along with the personal sacrifice and bravery of the men who served.

Go see it.

Mount St. Helens National Monument and the US Forest Service

I just spent yesterday at the Mount St Helens National Monument, and wanted to recommend it to anyone who passes through southern Washington or northern Oregon. Not to be missed, the US Forest Service do a great job of keeping it maintained, accessible, and making it educational.


Their budget is around $5.5 billion, which sounds a lot but there are a few things to consider - the maintain nearly 200,000,000 acres of public land (mowing my 0.1 acres of lawn is pain enough...) and nearly 400,000,000 acres of private land, manage forestry and mineral extraction, and then the most visible part to the public - keeping lands and national monuments open and available for education and recreation. That results in an estimated ~$35 billion of economic activity such as tourism. Seems a pretty good return on investment for the country.

Amazingly, half of that budget is spent fighting fires, so when you hear the calls for eliminating various agencies and reducing their budgets, remember that a lot of these agencies are a victim of their own success. Perhaps they should let a few towns burn down now and then to remind people that forest fires can be bad...

I'm only half joking there, because 20 years ago the cost of fire fighting took up 1/6th of their budget and it's been rapidly increasing since. They estimate it's going to double again in the next 30 years.

Changing climatic conditions across regions of the United States are driving increased temperatures— particularly in regions where fire has not been historically prominent. This change is causing variations and unpredictability in precipitation and is amplifying the effects and costs of wildfire. Related impacts are likely to continue to emerge in several key areas: limited water availability for fire suppression, accumulation at unprecedented levels of vegetative fuels that enable and sustain fires, changes in vegetation community composition that make them more fire prone, and an extension of the fire season to as many as 300 days in many parts of the country. These factors result in fires that increasingly exhibit extreme behavior and are more costly to manage. 

The six worst fire seasons since 1960 have all occurred since 2000. Moreover, since 2000, many western states have experienced the largest wildfires in their state’s history. 

In addition, more and more development is taking place near forests—an area referred to as the WildlandUrban Interface (WUI). Increasing densities of people and infrastructure in the WUI makes management more complex and requires more complex and requires more firefighting assets to ensure an appropriate, safe, and effective response that protects lives and property.

We're living with an administration that's trying to remove national monuments, sell off public lands to private only use, and is slashing budgets for departments like this - the FY2018 budget looks to be reduced by nearly $1 billion. The service keeps up with the firefighting - it has no choice - but this is at the cost of deferred maintenance and reducing other activities which support the land and recreation. At some point, this is going to the the US Forest Firefighting Service, and that's all. It may seem a minor thing when we're dealing with other major, immediate, crises, but the US Forest Service provides a critical function for our country, and we need to support it.

On a happier note, the trip into the Mt St Helens Monument was fun. Stop at the visitors center about 5 miles in from I-5 for the educational side, then drive up about 50 more miles to the observatory for some fantastic views of the volcano.


There are a ton of trails and other parts of the monument to access, we barely scratched the surface. Try and go if you're ever in this part of the world, and support the US Forest Service whenever you can, we all rely on them for way more than most realize.


Picking on the Little Guy

If you don't like politics, stop reading. For those who have to live in this world...

Anytime a politician or those in power target the poor, the powerless, minorities, and those who have no means of defending themselves, then take a close look because they are most likely either looking for a scapegoat or trying to deflect and distract from something else. 

No-one should be singled out based on gender, sexual orientation, religious choice, race, socio-economic class or anything similar. Any country that is diverse in its population and works to integrate, not separate, will be stronger because of it. Moreover, a country that looks after the weakest of its citizens is a society that will be just to everyone.

Authoritarian regimes get their start with scapegoats from small groups outside the mainstream. We should have zero tolerance for any such discrimination from our government. The recently tweeted 'trans ban' is exactly such an action. If someone meets the physical and mental requirements for the military, or any other role, they should not be discriminated against.

As an example you have likely already seen, I give you Kristen Beck, a transgender Navy SEAL. Kristen seems like exactly the type of warfighter we want, and wouldn't let things like 'bone spurs' get in the way of serving. Her quote sums up the entire situation perfectly:

It's a leadership issue, not a transgender issue.

America is better than this, and such divisiveness can't be allowed to stand. What is happening right now is not normal, and we can't allow it to become that way. To those who don't care about such people, let me make this pretty clear - Donald Trump doesn't care about you, or your tax cuts, or your coal mining job, or whatever you thing you can get from dealing with the devil, and one day you will be the target, no matter how white or male or Christian you are. Defend the little guy, and you're defending yourself.

Oh, and it's just the decent thing to do.



Sunday, July 2, 2017

uBeam Withdraw Claims of Wirelessly Charging TVs?

It seems someone at uBeam might read my blog, and has updated a recent posting claiming that TVs can be charged wirelessly. Their page for a recent job ad read:

uBeam is an innovation that will breed innovation. Ubiquitous wireless power will lead to a world with smaller batteries and thinner, lighter devices. With wires virtually eliminated, TVs can sit in the middle of a room cord-free and light fixtures will become “stick-on” without the need for routed power. uBeam is also a universal standard, making those bulky travel adapters a thing of the past. Imagine charging your phone, laptop or even your hearing aid virtually anywhere, without any effort. This is life powered by uBeam.

uBeam have made these claims before, such as in a panel discussion, Oct 2016, the CEO explicitly states TVs can be charged wirelessly with ultrasound, and a previous incarnation of the company website that explicitly states flat screen TV charging. The current company website still carries images showing TVs and other high power devices, so while not stated, it does seem to be implied they can be powered - hence my question as to whether it's a claim the company still stands by.

In a blog post here, I laid out the case why I believed this was near impossible/impractical due to a wide range of considerations. Well, it seems they may have accepted my carefully laid out argument, and have now changed their claims in that page:

uBeam transmits power over the air to wirelessly charge electronic devices. the company seeks to enable a world where device charging is a seamless and untethered experience. It will be the Wi-Fi of energy.

While apparently it's too difficult to do a grammar check on three sentences, it's good to see that they appear to have accepted that my argument is correct, and that it is utterly impractical to charge TVs wirelessly with ultrasound. They even noticed that it's not a universal standard and removed that statement, given the explicit ultrasound limit in most of the world would at best result in about 3 mW at a phone, enough to charge in around 3 months of it being switched off. Oh, and that standards usually have to be run through Standards Association like the IEEE and take years of input from a large committee.

This is the latest in a list of reduced deliverable or performance claims from uBeam such as 'faster than a wire' down to 'trickle charge' style rates, charging through your pocket, mass production in 2016 that never materialized, and claims of efficient and powerful transducers in 2015 that the Chair of their Technical Advisory Board apparently never saw.

Are they withdrawing their claim of wirelessly charging TVs with ultrasound, or simply saving that surprise for later? No one has stepped up to challenge my assumptions or working, and I am still happy to discuss that with anyone who cares to. As you can see, "Arguing the Point" in the manner I suggested seems to work, though I'm getting the feeling it's working better when I blog than when I worked there.

You're welcome, uBeam!

Thursday, June 22, 2017

EEV Blog takes on uBeam

Many readers of this blog will know the name EEVblog, it's a website and online forum for talking about  electronics run by Dave Jones, an Australian engineer. It's host to the uBeam FAQ, which puts together a lot of information on uBeam in one place. In addition to the forum, Dave makes videos where he delves into topics in a pretty entertaining manner, and for his 1000th video, he takes on uBeam.

Gotta say, he does a great job of covering the tech in an entertaining manner, not sure I could have done better myself.

An interesting point he makes is the difference between possible and practical, and it echoes a comment from one of my first posts a year ago that always seems to be missed:

"In theory, it can be done in limited cases, but in practice cost and efficiency issues will likely render it impractical." 

Enjoy the show.



Sunday, June 11, 2017

Arguing The Point


Someone on the internet is wrong. You wish to let that person know they are mistaken, as well as inform others to be sure they too do not mistakenly believe this to be true. How do you argue your point in an effective manner, disagreeing with someone, while maintaining civility? There's a good post on How to Disagree by Paul Graham which lays this out, and I'd like to touch on this, especially as it relates to science and engineering discussions.

We're living in a world where we are surrounded by incredibly complicated technology - sometimes the simpler that tech looks on the surface, the more complex it is. There's a large percentage of the population that would have a hard time explaining technology as old as the internal combustion engine in your car, and things get worse from there as you move through things we all use every day but barely know it - encryption and compression get the latest episode of 'House of Cards' onto your TV, but care to lay out how that happens for me? 

More importantly, how do you tell when someone is making false or exaggerated claims about technology? The facetious answer is "study for long enough to become an expert" however even then it's hard - there's a lot of technology out there, and only so many hours in the day. If you don't know the technology, and people are arguing about it, how do you evaluate the arguments they make? One way is to evaluate how they are arguing, even if you don't understand fully what they are saying.

The pyramid in the graphic above is an attempt to lay out Paul Graham's hierarchy (I have no idea where it's from, I'm not taking credit for it, thanks to whoever did it). The pyramid you see here contains the 'best' arguments at the top, the 'worst' at the bottom, and as you can see, it's wider at the base to represent that it's a lot easier to make the worst arguments than the best - 80% of everything, after all, is crap.

At the base it's fairly obvious - if one side is saying "the other guy is a doo-doo head" then they don't have much on their side. Sadly, you don't have to go to far above this for most people to lose critical thinking and an ability to evaluate what's being said. Ad Hominem is actually quite effective in discrediting a party with some audiences - for example saying "they're just a disgruntled former employee with an axe to grind" while ignoring any detailed points that person may have made, or whether they are even justified in being disgruntled. The most common form of argument is often simple Contradiction with no evidence to support it - "My client is innocent, and we're confident that the jury will agree." Frustratingly, we seem to be in a world where there's a media bias to he-said/she-said and placing the weight of argument 50/50, regardless of actual merit of the case.

I've never seen this fake-balance more brilliantly demonstrated than by John Oliver in this Daily Show segment on the Large Hadron Collider, and how there is a "50/50" chance the world would end when it was switched in. The part in question is at around 3:00, but I'd encourage you to watch the whole thing, it's John Oliver comic genius.


Dr Ellis is my hero here. Watch him start at the 'top of the pyramid' and refuse to be dragged down into what we're used to from media. He stays on topic, doesn't get tricked by Oliver (way harder than you might think), sticks to his point, and doesn't let himself be drawn into the arguments from the base of the pyramid. It's a short segment but really highlights how awful the media are in pushing junk science from those with limited understanding compared to those with deep knowledge - but where's the audience in that?

To further illustrate that point, and to show an example of an argument on a technical matter, let's take with this recent statement from uBeam 

uBeam is an innovation that will breed innovation. Ubiquitous wireless power will lead to a world with smaller batteries and thinner, lighter devices. With wires virtually eliminated, TVs can sit in the middle of a room cord-free and light fixtures will become “stick-on” without the need for routed power. uBeam is also a universal standard, making those bulky travel adapters a thing of the past. Imagine charging your phone, laptop or even your hearing aid virtually anywhere, without any effort. This is life powered by uBeam.

I'll take that one bolded point - that TVs can be powered wirelessly with ultrasound in the middle of a room and try and 'refute the central point'.

I'll begin by trying an argument against it:

"They're a bunch of stupid poopy heads" - No, that's bad, that would be Name-Calling

"They're just disgruntled current employees desperate to share their misery with the prospective employee and have no idea of the basics of physics" - No, that's Ad Hominem

"Powering a TV with ultrasound in the middle of a room is not a practical possibility, and is around one hundred times larger a problem than charging a phone in the same manner. While it is theoretically possible, the costs, inefficiency, and safety concerns are staggeringly high, while practical alternatives are low cost, and there is no economic demand to make this happen. Regulatory limits make it difficult in the US, and impossible outside the US." - OK, now we're doing somewhere between Contradiction and Counter Argument.

Let's move this to an argument from the 'top of the pyramid' by Refuting the Central Point

I'll begin by stating my assumptions:

We're talking about a large screen TV, not a small hand held. The TV is in a room you have some control over the infrastructure. The TV does not have a battery and needs a constant supply of power to work that can't be interrupted. From Energy Use Calculator I'm going to take 100 Watts as the power requirement for a 50 inch LED TV. We'll be assuming this is in the USA, and that the pre-2015 OSHA safety regulations are in effect and that in no location is sound over 145 dB used. Outside the USA the 115 dB limit give a transmitter and receiver 1000x area increase requirement. Note this will also apply within the USA should current OSHA limits restrict usage to 115 dB.

I will assume a generous 33% efficiency on receive, with 50% efficiency from transmitter to receiver incorporating both distance and angle of incidence. I will assume there is infinite power available into the transmitter and that efficiency from the wall socket to the ultrasound conversion is also 50%.

I assume each phone case sized receiver, at 5 by 10cm, uses $10 in parts, and we need to sell at 3x BOM to make money.

I'll ignore nonlinearity for the sake of simplicity, even though that's likely to become an issue, and limit the separation of transmitter and receiver to no more than a meter.

Now my calculations:

100 Watts powered means 300 Watts acoustic needs to be received. (100 Watts at 33% efficiency). This compares to around 0.5 Watts requirement for a phone, hence the "hundred times larger" comment. At 145 dB ultrasound is around 300 Watts/m2, meaning the receiver will need to be 1 m2 in size, that is a square of 1 meter on each side, or equivalent. A 50 inch TV is around 25 by 44 inches in size, (64 by 112cm or 0.72 m2)  so as a meter is around 40 inches, that means the receiver will be around 1.5 times the size of the TV. Ooops, better get to work on that efficiency.

Now a panel that's 1m2 is about the size of 200 phone cases, so around $2000 in parts, or $6000 in cost to sell and attach to that 50 inch TV, that costs around $500 right now.

The Transmitter needs to be twice the size of the receiver to take into account that 50% efficiency, so it's 2m2, and from the above calculation that means $12,000 for the transmitter.

Note that if the regulatory limit is 115 dB then the area scales by a factor of 1000 and the transmitter and receiver are each larger than the room.

For power supply, going with the efficiencies, the wall socket needs to provide 100 Watts, times 3 for the receiver efficiency, times 2 for the transmit efficiency, times 2 for the conversion efficiency, for a total of 1200 Watts. Fortunately this is (just) what a 110 volt 15 amp circuit can provide at 80% max load regulations allow (1300 Watts).

At 5 hours usage per day, and 12 cents/kWh average power cost in the USA, that's 72 cents per day to run, or $262, of which $22 is the actual TV use, the rest the wireless power system.

The additional 1100 Watts to use the wireless power system will be lost as heat (it's about a one bar electric fire equivalent), so in the winter that will save money, in the summer you'll need AC. I'll call it a wash to simplify this.

Summarizing the Argument:

Given the above, to power a TV wirelessly with ultrasound, it will cost $18,000 in the transmitter and receiver, with an additional $240 per year in running costs. Assuming efficiencies are as high as stated. And that no-one walks into the beam, since any interruption will make the TV switch off. And that you don't mind a receiver that's larger than the TV. And a transmitter that's twice that size and isn't too far from the TV. And that the room gets a bit warm. And that it's in the USA and the OSHA limits don't change to match the rest of the world.

But other than all that, isn't that much more awesome than running a $5 cord to the nearest outlet or paying someone to run a cable under your floorboards?

I think I'm going to call this "impractical".

OK, sarcasm over - I've run my calculations, providing all assumptions, workings, references etc so that anyone who disagrees can say "Your assumptions are faulty, here's what they should be" and then it's simple job to rerun those calculations get the new numbers, and judge from there. If anyone who is an advocate of wireless power would like to argue with these, feel free to correct me, and let's see where it takes the numbers. Or argue that my methodology is incorrect, I'm happy to do so - but like every other time in this blog where I have presented numbers, equations, and physics as core to my argument, I expect I'll be met with silence or more questions as to my motives. The top of the pyramid meeting with a response from the bottom.

My point to most people is this - if you don't understand the physics or details of a technical discussion like this, look to those presenting actual data, references, and their methodology and assumptions. If there is one side doing that, and the other calling names and questioning character, then you should likely consider one side's argument as superior to the other. If both are arguing methodology and data, then you may be watching a genuine scientific debate, which is good and healthy, it's what we want. If both are calling names, they're both idiots.


Monday, June 5, 2017

What Does It Take To Switch a "Phone Charging" Light On? Pt II

Following uBeam's demo, EEV Blog contributor Howard Long made a very interesting video showing how you can turn on a phone charge light with ultrasound. It's about 4 minutes long, with audio commentary, and gives more info in that 4 minutes than in the entirety of uBeam's demo. If this subject interests you at all, I encourage you to watch this.



From his comments (edited for brevity, read the whole thing here):

I could get it to light visibly with about 1mA at a distance of 2cm ... At 2cm distance, I had about 2mW, giving it a 2% efficiency. However, ... perhaps only 15-20% of the transmitted power appears at the rx anyway. So beam forming and reasoanably sized apertures on the receiver are essential facets for this to work.

... That camera thing is an Nvidia Jetson which looks like it's for visual device tracking. ... If it needs visual indication of where the target device is, and the sensors are on the rear of the phone, the phone will have to be used face down for a ceiling arrangement, and you won't be able to hold it in a normal fashion to make a call or use the screen. Even wall mounted, assuming nothing's in the way, you'll have to figure out new ways to hold your phone.

In its current form and key use, as a phone charger, this remains practically speaking a non-starter.

It seems an engineer reproduced a basic version of the uBeam demo in a day with about $20 in parts.

The phone charge indicator lights at 1mA, which implies 5mW (5 Volts supply) and so would take about 1000 hours (~6 weeks) to charge the phone - if it weren't for the pesky fact that a phone requires around 500mW to operate, on average, so it would make no appreciable charge effect at all. 

Now of course there's only a single element here, not a full array which could emit more power, but the key point is that a charging symbol tells you nothing about whether it is practically charging. You need voltage and current to know the actual power, and you need it at both transmitter and receiver to get efficiency (which he's calculating as 2% in this setup, pretty good actually for through air). Those are key numbers you need to have. From Howard's numbers 100 transmitters will get you that 500mW and maintain charge at a constant level, in an ideal world setup - possible but very large and introduce many questions on practicality and cost.

I like the way Howard also brings out a key point in this video - of course you can send power through the air by ultrasound. That's never been doubted or questioned, here or on the EEV Blog. What is questioned is how much power can be received, the efficiency of that, the safety aspect, the cost of transmitter and receiver, and the practicality for the user.

None of those points were addressed by uBeam, other than the emphasis on slow "trickle charging", implying the "faster than a wire" claims of 2015 aren't going to be happening.

Anyway, bravo to Howard Long for showing how to put together a short, clear, technically accurate demo from which you can actually learn something.

Friday, June 2, 2017

What Does It Take To Switch a "Phone Charging" Light On?

A few follow up points on the post from yesterday on the uBeam wireless charging.

I did like seeing this quote from the journalist:

Asked why the battery percentage didn’t appear to increase rapidly, Perry shakes her head.

“You’re thinking about it the wrong way, this is about a paradigm shift,” she says. “If you’re moving from your car to a coffee shop to work and your phone is charging while you’re using it, it’s no long about what percentage you’re at. You could stay at 1% all day.”

So it's an artful dodge of the question (that the journalist didn't press on), and perhaps an admission that the charge rate is not 'faster than a wire' as has been stated before by uBeam. It's more the "trickle charge" route, where you get tiny amounts of power over a long period of time. That "faster than a wire" claim was made at a time when the company was stating 1.5 Watts minimum charging which is much more than "trickle charge", and would fully fill your phone in 3 to 4 hours. Saying you stay at the same charge rate all day implies you are charging at an overall average of around 0.5 Watts, including all the times you are not around any uBeam transmitters, but if the charge rate is much greater than 0.5 Watts, why not say?

I noticed in that article the transmitter and receiver 'prototypes' back then in November 2015 were much smaller as well.


If there is actually a "trickle charge" regime, then the phones need charged as they are in use, and most use is a person standing or sitting holding the phone, fingers around the back, at around 45 degrees. Given line of sight, and assuming the 'bezel free front' of most modern phones, this implies the transmitters will need to be on the floor or base of the wall to get access, but will also likely be cluttered. Fingers on the phone case will prevent charging - unless of course you want to hold your phone by the edges as you use it (unlike in the picture above). I'm not seeing how trickle charge works with a mobile user, you need rapid charge in such circumstances. The practicality here, I'm not seeing. Maybe uBeam can layout the actual use-case scenarios they envision?

Also interesting was the quote from technical adviser Matt O'Donnell:

“When Meredith called me in 2015, I was curious and skeptical as hell, because you just hadn’t seen efficient airborne transducers,” says O’Donnell, dean emeritus at the University of Washington’s college of engineering, who now serves as uBeam’s chief technology advisor. “But holy moly, the leaps they’ve made in the past 18 months have been impressive.”

Hmmm, so all this advancement was made in the last 18 months, they had much, much less back then. But I'm confused because in September 2015 uBeam made this statement (among others):

“We’re at a massive inflection point,” said 26-year old uBeam co-founder and Chief Executive Meredith Perry. “We are about to head into a completely new phase of growth.”...In order to ease the transition into production, uBeam said today it has hired former Cisco Vice President of Supply Chain Management Jeff Devine as chief operating officer...“When we were seeking out an operations candidate we were looking at someone with decades of experience from taking a product from prototype to production,” said Perry. “He’s going to be the one that’s going to help us take this from our small shop to what will become our massive multi-million (unit) production next year.”

So which of those is true? Production ready in September 2015, or not? As with the "faster than a wire" claims from 2015 there are some implications as to 'perception vs reality' over the last few years if what Prof O'Donnell says is accurate. (COO Devine left his role at uBeam earlier this year before 'inflection' happened). For a further point of reference, I left the company at roughly the time these claims were being made.

The current receiver case is pretty interesting too. Looking at it, I'd guess 6 by 11 by 1.5cm which is larger than the phone itself, for around 100 cm^3 of volume. A standard battery for a Galaxy S5 is about 15cm^3 so you could have around 7 of those packed into that volume, giving you around 4 days of continuous use before recharging, and would cost about $70. If uBeam are using Murata (or Murata style) transducers in that case, there's around 60 of them at $3 each, so $180 just in transducers there. I'm not seeing the practicality or economics here.

(For those wondering - Murata are the primary maker of the parking sensors that are used in many cars, using ultrasound as the detection method. They're the small circles you see on bumpers, and individually look like cylinders about 1 cm each in diameter and height. They sell millions of them every years to the auto industry, and are around $3 each in bulk. You can go buy them yourself if you like.)

I did notice they have two different arrays that are used at different times, and I wonder if they are operating in the same manner, or if they are specced to handle different test conditions, and what is seen in these demos can't all be done on the one demo system. It's a little hard to tell from the videos as shown.

Now I could make a few more comments, especially on the posters in the background of the video and what they give away, but that's just going way too detailed even for my blog. 


Last point for now - the above picture shows a Kindle Fire on the right, and if you look in the bottom it's indicating "charging", but what rate is it charging at? 4.62 volts and 10 mAmps - basically  under 50 mW. To give you an idea of what that amount is, a typical phone batter is in the 5 to 6 Wh range, which means at this rate it would take over 100 hours to charge your phone at that rate. That's also assuming the phone is switched off, as it's typically consuming at around 500 mW so without that level of 'charging' it's consuming power faster than it's receiving it. I'm not seeing the practicality if that's the case. (A demo of a charging indicator coming on can be found in a newer post, here)

All this indicates is that the floor to show a device charge light come on is not the same as actually charging it - you need to see something like the screen on the left with voltage and current to know actual charging rate. This floor varies by device (iPhone seems to trigger at a higher floor than Android, and the floor varies with charge level IIRC), it's possible it's charging much faster (faster than a wire even?), but if it is, why not say?

As has been said before - physics doesn't prevent you sending power via ultrasound, or RF like Energous does, but can you send enough power to be useful, safely, efficiently, simply, and cost effectively?

Thursday, June 1, 2017

Someone was paying attention

Almost immediately after my article yesterday, it looks like someone at uBeam was paying attention and actually did a proper, adult, professional PR piece and got the company onto the front page of USA Today. Much less embarrassing! :) It does also show part of my article was wrong - at least some people care!

To very quickly give a summary:

Reporters buy a phone at a local outlet to use charging (shows phone isn't tampered with, well done), put it in the brick case, and get the charge light to come on. Shows a device with an IR camera for tracking. Done with more than one phone at around 4 feet. They go on to say:

The technology is at least a year away from commercialization, and it faces significant hurdles from ever getting out the door of this 30-person start-up. Even though it can at present power a handful of phones, it's not clear what leaps need to be made to charge a busy coffee shop. And consumer questions will linger about safety as well as cost.

So at least they maintain some skepticism.

In the short time I have available this morning, and I'll update later tonight, I'll make the following comments:

In all this time, have reporters still not learned to press on the key questions? "How much power is being received?", "How much is being sent?", "What's the efficiency?", "How much does it cost?", "Have you proved it safe?", and "If this is what you have now, what were all those 'prototypes' you were talking about 2 years ago?". But those are actual questions that matter, and basically we know the same today as we did yesterday (which indicates it was an awesome PR piece, lots of coverage with no actual info).

Technically, it's still hard to say exactly what's being done, and there's not much to add beyond my earlier articles. The video does make it look like off-the-shelf Murata devices are being used and focused into a tight beam straightforward. Efficiency and safety questions are dodged.

Is this enough to convince someone to put more money in? Most likely, so let's see if someone big enough to price a round steps up or if it's smaller less sophisticated investors again.

Wednesday, May 31, 2017

What's In A Picture?

Last Wednesday morning someone emailed me the below picture from uBeam, asking if I was going to be writing about it. A few seconds later, I realized that I probably wasn't, as really there's not much new to say - anyone who understands hardware and business knows what's going on, the rest don't want to be educated or are investors. I also realized a couple of days later that pretty much no-one else cares either - I only had a single journalist call me about it and after giving him my opinion, he basically said that he was just keeping his notes up-to-date and editors weren't at all interested in uBeam. Since then, I've had a few questions from the tech side, and I noticed that the EEV Blog is commenting on it, so given I've a couple of spare hours tonight, here's my take. (For those who have asked, I'm in the middle of a piece about the recent Silicon Valley: A Reality Check blog post that got some attention a couple of weeks ago and will get it up soon, honest - read the original if you haven't already) 


I'm going to split this into three sections - my reaction, the tech, and the business implications so people can skip bits that aren't of interest.

The Reaction
What we have here, I'm going to assume, is a uBeam transmitter (large box with hexagonal tiles up top) and attached to the phone a receiver (the black brick in the bottom right). What was my first thought in seeing this? (After finishing laughing that is) Clearly they aren't any better at handling publicity than they've been over the last couple of years, with the PR firm clearly so asleep at the wheel they don't even know they're being ridiculed. Given they can actually manage to turn a positive article from a journalist into another piece pointing out the ridiculousness of typical day to day life in the company, it's no surprise that this quality a job was done here.

This, I believe, is the first official public unveiling of a setup that's been promised almost every year since 2011 or so, from a company that's raised $25 million. Is there simply no realization of how bad this looks, or is there an absolute lack of shame or care? Your big reveal should amaze and wow, it should scream that you are delivering, at the cutting edge, that you know how to get the details right from the finest detail to the grandest strategy. What this says is "Hey Granny, do you think I'll win the school fair with this?" not "Thanks investors for the $25 million, we're about to change the world!"

How unprofessional does this look? First thing is that they don't seem to be interested in tidying up the lab and staging before taking a picture to send out publicly, with bags of paper, white board, old carpet, and generally an unimpressive setup visible. It's like leaving your dirty underwear on the floor when your partner's parents come round for the first time. It makes me wonder if, like President Trump impulsively sending out Tweets in the early hours while no-one is minding the store, uBeam staff came to work in the morning to see the FB feed and said "we posted what?". If any of that team have been laughing about 'covfefe' then perhaps it's out of sympathy for the Whitehouse staff and what they have to go through every day. I read the goings on with President Trump and his staff and every day I see yet another corollary to working at uBeam - just in that case it's actually about something important.

Allow me to give uBeam some suggestions as to what to do next time. Begin with "decide the image you want to present to the world". Is it "sleek consumer design that Jony Ive would be proud of" or "cutting edge sci-fi level tech", for example, then setup the situation to reflect that aesthetic. For the former, put it in a sleek case that you've built with impeccable industrial design, you know, kinda like the one that was shown at the Upfront Summit last year? Any reason you couldn't use that? Put it in a user setting with happy people pretending to charge their phones, at the office or at the coffee shop. For the sci-fi side, get it in the lab with oscilloscopes and other equipment arranged in an impractical manner that would never actually be used that way but looks really cool to the average Joe. Hey you could even take that last setup to the next step and even show the voltage and current at transmitter and receiver!

Whatever you do, decide on a marketing theme that can sell and take the time to do it justice.

Along with the pics, actually put out a press release that says something. Take a look at Energous, they're perpetually 18 months from product after a few years and yet they put out professional press releases. You've a model to work from - take a look!

And one final suggestion - and it's not like anyone would have ever told you this before - when you're doing wireless power, don't show any wires in pictures of things being powered!

Seriously - I've not worked there since 2015 and I'm embarrassed by this.

The Tech
Now some time was taken to do a little blurring on the pic - you can see over the box that photoshop had a blurring filter applied in a circle over it. Perhaps this is to obscure that it's likely off-the-shelf components from Murata as I noted in a previous blog entry. (It could be an image overlaid to truly obscure and mislead, but I don't think so).  That's a bit strange, as I have pointed out in other posts that there's no issue in putting a mesh over the front to obscure what's behind, those Murata devices have it done to them by default. That mesh would also obscure the screws in the plastic and make it look at least a little more professional.

Blurring aside, the transmitter is now in a hexagonal arrangement, unlike the regular grid seen at the Upfront Summit, with 7 hex panels each around 15 elements across, so 45 or so elements top to bottom. If it is the Murata 40S4S then that's 45 cm top to bottom, and around 1600 or so elements total. At $3 each, there's $5000 of transmitter parts right there, and those are parts that sell in enormous volumes to car manufacturers so there's not a lot of room to lower the prices further. That implies a $15,000 transmitter, minimum (typical 3x markup from COGS to sale price). The box is maybe 3 to 4" deep, and it's positioned so you can't tell if there's a ton of electronics or power supplies sitting behind it - there were a lot of electronics in a large box in the Upfront demo, perhaps they've been downsized and rotated to fit in the box. Regardless, it's a pretty ugly box and nothing like the prototype that we were given a 'sneak peek' of at the 2016 Upfront Summit - what could have happened?

The hex pattern is interesting, and I wonder if it's been setup to beamform along the center line only only, no steering, in an annular array manner (concentric rings). This would really simplify the need for electronics, but if there are bad grating lobes (as you will get in an array where the pitch is larger than the wavelength), you can probably charge off to the side anyway as there's uncontrolled energy going in lots of directions. Basically, it doesn't seem the pitch is improved to allow for better steering and any real control - a big issue for safety in my opinion (beaming energy, you kinda want to control that). It also would not be representative of an array capable of steering in arbitrary directions.

The phone is attached to an enormous receive case that could be described as a 'brick' - it looks to be about 1.5cm thick which would allow for a number of the Murata transducers at about 1cm thick, along with an electronics board. Now an advantage of such a large box is that it will shield the MEMS gyros in the phone from vibrations which can damage them, but I doubt that's what it's there for - it's simply the smallest that can be made with Murata commercial transducers.

It may be that you've heard someone say that'll get better with "Moore's Law for Transducers", implying the transducers get half the size or twice the performance every 18 months. On the face of it is a bit silly as Moore's Law refers to the density of transistors on silicon and has nothing to do with ultrasound, but when you think about it and dig deep it's even sillier when you realise that the performance of ultrasound devices is generally tied through the laws of physics to particular device dimensions. Given those Murata devices were released at least 2 to 3 years ago, shouldn't there have been some major improvements to them by now?

But the phone is charging! Errr, well it shows 100% charge, but not that it's charging, and as before no idea of voltage, current etc that we really need to know the charge rate, nor of the overall efficiency of the system. Also, from memory, at >80% charge level the iPhone still shows charging even when less than 250mW are received.

So what do we learn from this picture? Not much other than there's a rearrangement of the previous demonstration, it's still apparently off the shelf parts, the receiver case is enormous, and there's no-one experienced in charge of publicity at the company to put out good pictures. As before, there can still be power received, even in the low 10's to 100's of mW, but as engineers and physicists have been saying all along, it's not transmitting power via ultrasound that's in question, it's can you do it at a useful amount, safely, in a practical way, at an acceptable efficiency, with hardware at a reasonable price. This still answers none of those.

The Business Side
As noted above, this looks like demo hardware, not even prototype, and still hasn't been shown working or efficiencies given. Can it work in a practical situation like an office or a coffee shop, or under standard use cases? What's the efficiency? Can it steer? How does it know where the phone is and track it? Most importantly, is it proven safe? Is it even legal at the dB level in most countries?

Reaction on Twitter seems pretty muted - in a week there's been a whole 3 replies and ~100 'likes' which is pretty telling. Seems the journalists know their audience...

What's really interesting though is that uBeam have not yet announced a new funding round. It's near 4 months since the Upfront demonstration, enough time to have completed a funding round with such slam-dunk technology. I'm saying 'no funding (yet)' as there are no new job ads, no publicity, and if one of the 'big guys' who a company will already have had come through to price the round were interested, they would not allow pictures of the tech to get out, especially if it's an Apple or a Google. Four or five months into fundraising things are starting to get stale, everyone knows that the first guys you spoke to haven't come up with terms (or acceptable terms), and that holding out will just get the company more eager to deal. Even with reducing burn rate by shedding senior staff and closing offices, runway only buys you so much in this type of situation. It's getting close to summer as well, and VC's are notorious for disappearing for July and August.

I have been expecting it announced soon, since there's no shortage of dumb money to go around these days, as when a 'low toxin butter-coffee' company can raise over $19 million, it seems anything will get funded. Perhaps they're holding out for the best valuation and getting that $100m round on an Energous-beating $400m valuation?

Who knows? And, from the public reaction to this picture, who cares?


Sunday, May 14, 2017

Recent Investments in Consumer Ultrasound

Earlier this month a consumer ultrasound company received a large series B funding round, taking in a further $23m to bring their haul to around $40m in total. It wasn't uBeam, it was UltraHaptics in the UK, who are using ultrasound to induce sensations and feelings at a distance (Haptics means 'relating to the sense of touch'). Think touching a 'key' on your phone when the screen vibrates or there's a buzz, even though it's not feeling like a key, the presence of some form of feedback tricks your brain and lets you know something has happened.  

It's likely a good complement to AR/VR and while it won't ever feel like solid objects or real things, the fact that there can be some form of feedback is a huge benefit. Imagine feeling something on your fingers as you touch a virtual keyboard, or sensations on other parts of your body as signals to interact with the virtual world around you. 

From the UltraHaptics pictures, it looks like they are using Murata MA40S4S car parking sensors (at least that's what they show), just many of them together in a square array (it's what's under his hands, just in front of the laptop). These are commercial off-the-shelf parts, and not ideal for a phased array, but unlike uBeam who also appear to be using them, are unlikely to be working at a power level where this becomes a safety issue. An array like this can be controlled to send beams in directions controlled digitally, but also as a receiver to allow imaging of the surroundings.


UltraHaptics seems to be working with the automotive industry according to the TechCrunch article, which surprised me, as there are fewer options within the car for that kind of feedback. What there is more demand for is sensing, both of passenger location within the car, and sensing close in around the car at low speed such as during parking. Other sensing systems such as LIDAR aren't always best close in, at a few meters or less, and ultrasound can do that job - essentially it's a high-fidelity version of the reverse sensors many cars have these days. I do wonder if they've found that there's another more lucrative application for their technology.

Another company in the ultrasound haptics space is Emerge, based in LA, and they have to be pleased that large investments are going into this space. Interestingly, Emerge has been on uBeam's radar, with rumours of a 'Cease and Desist' being sent their way for having the audacity to hire an engineer previously employed at uBeam (one wonders if the other 19 or so companies now employing the entire first group of uBeam engineers will also receive such letters). It's hilarious that anyone would be naive enough to think in California that a non-compete or restrictive practice could be placed on the employment of any engineer, and might indicate some desperation on their part. With Energous covering the IP space in wireless power (RF and ultrasound) as well as multiple applications such as communications, apparently few uBeam patents in the pipeline, and Emerge and UltraHaptics cleaning up in the haptics and possibly imaging spaces, that there is anywhere for uBeam to pivot to if (when?) the wireless power market proves unattainable.

Overall, I'm glad to see investment in this area - there are challenges for these companies but definitely some interesting opportunities - but also that there are engineering companies out there just quietly getting on with the job of building technology and delivering products.

Saturday, May 6, 2017

Raising Capital for a Startup: Convertible Debt

You have an idea, it's awesome and will change the world, something like a juicer or a toaster oven. Right now only you can see the potential, and you just need some funding to get started. You can use savings, but ultimately anything that's going to be amazing needs cash either to scale, or to get to market quicker - how do you raise that money? 

You can go to a bank for a loan, but they'll ask about sales, revenue, and profit, and seeing as you have none, they won't talk to you. So instead you go to an angel  (a rich individual or small group of rich individuals) or VC company, and offer them equity (shares) in your company in return for the money - but you still don't have anything, so how can they value your company to determine how much stock they should own? It's a large and expensive exercise to work that out (and you have no money to pay that with), at the end of which you may not think it's fair or viable for your needs.  

So with no revenue, product, idea of actual value, how can you reasonably raise money? A common way this is done is Convertible Debt. Convertible Debt is a hybrid between a loan (debt) and equity (shares) that tries to keep things simple in terms of the paperwork to get going, and puts off the tricky bit about valuation until later when there's more information to base that on.

Here's how Convertible Debt works - the company and investor agree on an investment amount, say $100,000, which the company will use to further the business/product. This is usually after a few rounds of meetings and presentations, where the founder has shown a basic pitch deck, presented a plan and a vision, and been vetted to some degree by the investor. Each Convertible Debt note can be different, I'm presenting a common version, but expect every one to have its own idiosyncrasies.

This money is given as a loan, same as with a bank loan, complete with an interest rate and repayment period - for example it might be at 3% interest, with a 2 year repayment timeframe. At the end of those two years the debt, along with interest (which has been accumulating all that time), is to be repaid in full. There are no debt payments made during that time, unlike a regular bank loan. 

That's pretty straightforward for a loan, but there's the equity part - if there is a "funding event" at some point in that 2 years (usually defined as a certain total amount of money raised) then the loan converts instead to equity (shares). Basically it starts as debt, then converts to equity, hence convertible debt.

How does the 'convertible' part happen? At some point a valuation of the company can be performed - but here the company has (say) 2 years of work behind it, perhaps a product prototype or early customers, and the VC firm putting in the Series A money (sometimes called "institutional money") has the capability and reputation to place that value on the company.

So, let's say that $100,000 of Convertible Debt was put into a company that a VC later values at $10,000,000 pre-money, puts in $2,000,000 for a $12,000,000 post valuation - that converts based on the pre-money valuation (usually, but not always) so those original investors get around 1% ($100k/$10m, ignoring interest) of the $12m company. They gained about 20% ($120k) on a pretty risky bet over 2 years, so it's a decent return but not earth shattering considering they basically made the company possible, were likely to lose everything, and the VC now has ~17%. 

This is a little unfair to the original investor, so this is why there is also a "discount" or "kicker" in the Convertible Debt agreement, where there is a discount on the price, often around 20%, so they get a bit more. With a 20% discount, they'd be getting 1.25% of the company ($100k/$8m) - now they've made a 50% return in value which is better, but still not that great, especially when that money isn't liquid and they still have the risk of future rounds of funding and it all going wrong. If the company happens to go stellar with that initial money, say a $100m valuation, then the investor gets an even smaller % of the company - that's a great deal for the founders and VCs!

Sophisticated investors in Convertible Debt often ask for a cap on the note (since it's debt, the term 'note' is often used for Convertible Debt). In the case above, they might have a note with a cap of $2m - in that case if the valuation goes over $2m at the Series A, the conversion of debt to equity is calculated at the cap - so it's ~5% ($100k/$2m) and now they've got a (paper) 500% gain, which will make them much happier. (Whether cap and discount both apply is down to the details of the note, sometimes it's just one of them).

So Convertible Debt has the benefits of keeping things simple in the legal papers (it can be done in a couple of pages), puts off the tricky aspect of valuing a company, and allows for the upside of equity in a growing company if things should take off. This is why Convertible Debt is a common financing vehicle early in a company, often in what's called the 'Seed Round'. 

What are typical terms? Usually these notes are for amounts in the $10k or $100k ranges (by definition it's a small company trying to prove things out, with a 'non-institutional investor'), but sometimes go into the millions. Interest rates are usually nominal, say 1 to 5%. The discount is also variable, but 15 to 30% is not uncommon. The term is a bit trickier, how long to make that? Well, you need to be actually able to do something with the money, and then with your new prototype or product go to a VC and the process of raising a Series A. Conventional wisdom tells you that if all goes great, a Series A raise takes 3 months, and it generally doesn't go well so assume it's 6 months. Basically, however long it's going to take you to get to something worthwhile, plus 6 months, is how long you want. For example, if you think it's going to be 9 months to a year to get to prototype, don't make your note term shorter than 18 months, and you probably want to give a little headroom in there for things going wrong. I've rarely seen a single year as a term, but I'm more a hardware person and those projects take longer, with the bulk in the 18 month to 2 year range - longer than that is rare as running a company for 3 years on convertible can be tough. Terms can also be conditional - that is they change with certain events - for example the discount may increase at certain points during the term of the note, starting say at 15% on a two year note and increasing by 2.5% each year. A founder may offer these terms to entice the investor to give a longer term, or the investor may want to encourage alacrity on the part of the company.

Most times both investor and company assume that it will be a clear situation of successful funding and conversion, or that the company has gone under, but if it's in limbo or limping along as often happens, things can be uncertain. What happens if things go wrong?

The most common way is for the term to expire and there to have been no funding event - the investor is due the loan back with interest, but no institutional investor agrees the company is worth funding, and we assume there is no money in the company to repay it. What happens then is the same as with any debt - debtor must come to an agreement with lender as to next steps, and this could be anything from bankruptcy to a renegotiation of the debt. With smaller amounts, both sides might just ignore it and pretend it didn't happen, with legal costs likely to outweight the investment amount, but the larger the amount the more an agreement needs to happen. Bankruptcy doesn't make sense, usually, as driving the company under ensures no chance of future success, and they are unlikely to have significant assets to liquidate to pay the investor back. It makes more sense for the two parties to come to an agreement, for example extending the term for another year while increasing the discount by 10%, and so it's usually recommended that if money isn't already in, start talking to your Convertible Debt note holders at least 3 months prior to term about what happens next.

Regardless, any institutional investor coming in for a Series A will want that paperwork cleared up before their money goes in, as they don't want a lawsuit or trouble later on.  This leads to some interesting situations where the Convertible Debt investor can start to demand beneficial terms from the company and hold up the Series A, or the company can demand the note holder give concessions like the discount rate or they won't go ahead (it's a "give me what I want or I shoot my company" tactic but I've seen it work). In those cases, it's down to bad blood between Convertible Debt investor and founder, and if it wasn't before it certainly is after.

One interesting permutation I've never seen play out is if a company does a convertible note between institutional rounds - for example between Series A and B when there was an original valuation and equity investors. It's odd, but it does happen, as LA Business Journal's Garrett Reim notes this is a route uBeam opted to follow when they took an (up to) $15m Convertible Debt round in July 2015 after a ~$10m Series A in summer 2014. This leads to a lot of possible weirdness that may or may not occur depending on how uBeam's fundraising for their Series B (which they must be deep into, now nearly 2 years from last fundraise) plays out.

First weirdness is that the Series A VC investors, who all get Preferred Stock that guarantees them paid out first from any money, are very unusually in the queue behind the convertible debt for being repaid, as debt always takes priority in any liquidation. This puts the lead investor in the position of desperately wanting a conversion from debt to Common Stock so they can take priority again.

Next is that the convertible round size was likely based on the then valuation of the company, with the expectation it would rise in the time between loan origination and maturity. If the situation arises where the Series B is a down round (lower valuation) than the Series A, or even similar, then the Convertible Debt investors will end up taking a huge % of the company even before the shares of the new Series B investor dilute the company further.

Lastly is that if the company had a valuation prior to the Convertible Debt investment, then there is the assumption that there is actually some value there, be it product, customers, IP like patents, or even remaining cash in the bank from the original Series A. A Convertible Debt investor at the note maturity may decide that liquidation is the best outcome for them, especially if they can get paid off first (perhaps they know the company has more cash in the bank than they are owed), and they do not think the company has much of a future. This can lead to an acrimonious situation as the investor plays 'hardball' with the company - that's not going to happen at the $100k level, but go past $1m and things are different. An element of that played out with Theranos when one of their investors, PFM, sued for their $96m investment back claiming fraud, when they know Theranos had $200m in the bank - basically taking the money before lawsuits and time removed the potential for any return.

Overall, Convertible Debt is a well understood way of raising money in the very early stages of a company, with simple terms and paperwork, but it can lead to some very difficult situations should it not convert at the end of the term.  There are other options and variations, such as SAFE, but in the interests of simplicity, I'm focusing just on that.

Update: Interesting Techcrunch article on the issues that SAFE and convertible note rounds can cause. Further reading on the matter - some key quotes that emphasize what I wrote above:

Why is this troubling? Because it has become more common for VC funds to pass on investing in deals altogether, solely because the waterfall of notes would consume too much equity. If outstanding notes prevent a new lead investor from meeting their fund’s required ownership targets without triggering a complete company recapitalization, a null set of equity distribution possibilities may arise.

In these cases, the only valuations that makes sense for a Series B lead investor force the dreaded “down round.”

Saturday, April 29, 2017

Energous Challenge uBeam in the Ultrasound Wireless Power Space

Finally, I get to write an post containing two of my favorite wireless power transfer companies, uBeam (which I've written about here, here, and here), and Energous (which I've covered here, here, here, and here). Now I could make a joke about "Red Shirts vs Stormtroopers" here, but that analogy isn't correct, as despite what I believe about Energous' ability to deliver on the at-distance wireless power transfer they claim, as a company Energous has been run well and it seems they know how to 'play the game'. (I don't have to like what someone is doing to see how well they do it, for those about to criticize.)

As I occasionally look through the IP portfolio for various companies, discussing them with like-minded people, this weekend we noticed something interesting in Energous' applications for patents - while they are extremely prolific in their patents applications, it seems they are now generating IP in wireless transmission of power via sound, which is uBeam's stated goal. Energous are known for claiming an RF based power transmission method, but now it seems they are making sure they have a wider technology portfolio.

As the EEV Blog's uBeam FAQ clearly points out, the basis for ultrasound wireless power transfer is covered in Charych's 2003 patent for BC Systems - System and method for wireless electrical power transmission (US6798716) - but if uBeam has been stating publicly or to investors that uBeam owns the wireless power via sound IP portfolio entirely, thus locking out any potential competitors or rivals, that's no longer the case as Energous is applying for, and being granted, multiple patents covering wireless charging with sound. This puts them in direct competition with uBeam.

Granted:

Application:

This is likely not an exhaustive list and I'll update over time. The primary author, founder and CTO Michael Leabman has been a very prolific inventor here, and you can see a list of many of his patent applications and awards here. It seems most of these sound related ones were filed in 2013, over a year prior to uBeam's major Series A funding in 2014. These are now only beginning to be issued as patents, as it typically takes 3 to 4 years from filing to being granted, which implies that many of those currently listed as 'Application' may be on the verge of becoming 'Granted'. If so, it won't be long before Energous' IP portfolio in ultrasound rivals uBeam, with a further extensive range in the RF space.

Also interesting are some of Energous' patents that don't specifically state 'sound', but simply talk about focusing waves and energy - making it equally applicable to both RF and acoustic waves (the equations governing both are between similar and identical, the same basic physics applies to both). It seems they've been doing this since at least 2015, with patent applications such as:

"Embodiments disclosed herein may generate and transmit power waves that, as result of their physical waveform characteristics (e.g., frequency, amplitude, phase, gain, direction), converge at a predetermined location in a transmission field to generate a pocket of energy. Receivers associated with an electronic device being powered by the wireless charging system, may extract energy from these pockets of energy and then convert that energy into usable electric power for the electronic device associated with a receiver. The pockets of energy may manifest as a three-dimensional field (e.g., transmission field) where energy may be harvested by a receiver positioned within or nearby the pocket of energy."

As you can see from this, Energous have been careful to ensure their patent applies to all forms of energy, not specifically RF - this wording could equally apply to acoustic energy as well. They have multiple other such applications such as:

Systems and methods of object detection in wireless power charging systems US20170077764 A1 which states video images will be captured and processed to ensure correct targeting of wireless power, Methodology for multiple pocket-forming  US20160241044 A1 covering charging multiple receivers from a single transmitter for any energy type, Systems and Methods for Real Time or Near Real Time Communications Between Electronic Devices which covers feedback between transmitter and receiver via any means, Systems and methods for nullifying energy levels for wireless power transmission waves that covers minimizing energy in the non-targeted areas for safety,  Systems and Methods for Identifying Sensitive Objects in a Wireless Charging Transmission Field for realising someone or something is in a wireless power field and dealing with that safely, and Systems and Methods for Generating and Transmitting Wireless Power Transmission Waves which basically covers everything in wireless power transfer.

I could go on about all the specific applications they are patenting, such as using TVs or other electronics to transmit, identify receivers, communications, charge healthcare products, identify valid receivers (hardware DRM) - basically covering absolutely everything in wireless power transfer including, it seems, ultrasound wireless power transfer. You can search in the link above and find a comprehensive list - it's quite impressive.

Does this mean Energous are going to be sending power via ultrasound? In my opinion, absolutely not - in fact I don't think they will be producing consumer devices in the multi-meter range, faster than a wire, multiple device, efficient, and cheap methods people might imagine - but they are cleverly expanding their portfolio to literally own the entire wireless power transfer space. This could be used both defensively, and offensively, and in the hands of a $300 million market cap company with resources, can be a terrifying thing for a smaller company looking to break in, and makes them a more attractive purchase or licensing deal recipient for a larger company. 

In the end, I wouldn't be surprised to see Energous make most of their money from licensing deals on individual patents, and never actually release a product like originally claimed. Smart strategy on their part, licensing money is pure profit, hardware is, well, hard.

What does this mean for uBeam? The first thing is to look at their public patent portfolio (both application and granted) - which you can see here. It's a much less extensive list, and something I was surprised/shocked to see is that the latest filings such as Performance adjustment for wireless power transfer devices are from my time at the company, and I left in 2015 - in fact I'm one of the inventors on many of the recent filings, and in some cases, such as the one listed above, every single one of the inventors has left the company. Now it could be that many are filed and simply not published for the public to see, or that the company is pursuing a trade secrets rather than patent approach (would be 'unusual' for a  hardware company in my opinion, but possible), but it's not nearly the in-depth and broad range of patents that you see with Energous. Further, the uBeam patents don't seem to cover Energous' applications and fields, while Energous cover uBeam's.

It would be interesting to know how a company plans to defend its patents, both in prosecution to the patent office and in court during litigation when they don't have the inventors on staff anymore, and in some cases there is clearly a poor relationship between the company and the former employee/inventor (looking at no-one in particular ;) ).

I would expect this to be quite troubling to uBeam, as a startup - especially one with no product, licensing deals, or third party evaluation/demo - is heavily reliant upon its IP portfolio for valuation purposes, and to have to defend patents, or work to nullify others, is an expensive legal proposition. 

What should also be considered is the effect on potential investors, as uBeam discloses to them during any fundraising that they do have competition in the IP space, from a company with apparently a similar or larger portfolio, that is larger and more significantly funded such as Energous. Since the last publicly stated fundraising round for uBeam was in July 2015, it's entirely possible that fundraising is going on right now.

Overall, it's a tremendously interesting development, and one I'm looking forward to seeing how uBeam respond to this aggressive encroachment by Energous.