Hi Welcome to everyone's favorite segment mailbag. Let's get straight into it. This one is from Emmett L Brown No idea who Emmett our Brown is so let's let's give it a go. Everyone loves a mail bag so she's not packed very well.

What the hell? What a t-shirt we'll check out and what's that is this? It's a Microsoft Surface tablet. Um, with some young-looking dude on there doing a piece to camera? What Video blogs? No future in video blogging? What are you doing? There's absolutely no future in video blogging. That's crazy. Shut up.

Shut up. Can't shut this guy up. Cannot shut this guy up. Here's me: I'll shut up.

Yes! April 4th 2009 I Was going to insert a joke about Doc Brown a falling off a toilet but David said that no I want to get it. So no there is no fall off a toilet joke we talk about. Anyway, this is the 1000th episode and I thought we'd do our a medley of stuff that people like different segments so got to be brief. Let's get to it, shall we? Everyone loves a tutorial.

Let's get to it. Come on. Transistor as a clamp in then I is one you may not have seen before. you probably won't find it in any textbook really or pretty much information on this anywhere.

and it's a bit of a naughty circuit. We're going to use transistors the way you shouldn't use them, but there's a reason for it and it does actually work from a big-name manufacturer. Let's look at Bipolar Junction Transistors how we can turn those into a clamping? Zener diode, a bipolar clamping Zener diode that can use in either direction to clamp impulses and overloads, and ESD and all sorts of other stuff. So let's take a look at it.

This is a configuration here. The two collectors join the two bases joined and we've got emitters either side. It's really weird. They're both NPN is, but one slipped up the other way, So you might think, how can this conduct well? We'll find out.

now. don't take a look at this. Let's go straight over to the equivalent circuit here: base collector, emitter of an NPN BJT Bipolar Junction transistor. You probably won't see this configuration in your usual explanations of the equivalent circuit of a transistor, but because we're using it in a certain overload mode, it becomes relevant.

There's actually a Bipolar Junction transistor. B can be modeled as basically two zeners inside. There's one Zener from base to emitter. In fact, because it's fully biased like that, it's actually our working as a diode, but it's in its reverse configuration.

If you look at the data sheet VEB o or the voltage sometimes called V RB BR for breakdown is the emitter base of breakdown voltage in reverse, it will break down and act like a Zener and about 5 to 10 volts. I've done a whole video on Zener diodes. It's really cool. Detail down below.

Check it out. It's typically for most Bjts can be high over typically five to ten volts. It's actually an avalanche breakdown. Anything under five volt is actually a Zener I Explained that in the other video linking down below and base to collector.

we've got what's called V CBO and you usually find Ve Bo and V CBO in the absolute specs of a datasheet. Like, don't exceed these Magic smoke escape Warning: Will Robinson So usually we don't want to operate, but today we are. We going to be pretty naughty. So in the reverse configuration here, because of the construction of the BJT, it has a much higher than a voltage, typically 20 to 100 volts.

Something like that can be higher, but we'll run with these. So how does this work? Well, Your base emitter Junction Like this: If you've got a positive voltage here and a needy voyage here, basically me, that is just your dire drop. It's just a diode. It's a Zener diode, but in the full configuration, so no point 6 volts in near enough, then I'll reverse because we're actually using base emitter base.

Positive negative: it's acting like a venom to give us a roughly. we'll call it six volt drop. So anything over six point six volts here will cause this to conduct and clamp. so in, if you've got a series resistor on the input, it clamps everything.

fantastic and likewise in the other direction. Negative and positive Bi-directional 0.6 volts and six volts total clamp at plus minus 6 point 6 volts or thereabout. Let's go to the bench and check it out is the same configuration that we had before. We've basically gotten our Zilla's I've got pen double to double to S4 Agenor input series resistor here, and the voltage of the supply input here, the voltage of the Zener across here, and the current flowing through the circuit here.

so you can see at one volt for example, there's no current flowing through there and it's just. it's as if this isn't there because it's not clean yet. But as soon as we reach the threshold values, you know notice that there's basically no our current there. Okay, but if we start might start to conduct a little wee bit because these aren't great transistors.

Let's take it up to 10 volts. Bingo. It clamps at Eight Point Two, six volts and we can actually go up higher. Let's go up to twenty volts.

It's still claps at Eight Point three volts. and because it's bipolar, it works in the other direction. Negative. There we go.

I Just inverted the input voltage minus twenty volts. it still clamps at Eight Point Three. Then freakin' tastic and these are quite fast clamps in great use for overloads. Now we can actually show the AC our configuration of this, so let's plug it in.

I've got a couple of disproves here. Don't really need it, not really higher voltage, but check that out, we can see how one waveform. There we go. It's actually clamped it like that.

There we go. We actually turn it down like that. There's actually two waveforms in there. You'll see because it's not clamped so they're equal.

But once you actually go up in voltage, then you'll find that it clamps. there. we go and we'll go up up and said start to clamp fan tastic. So it's a bi-directional clamp.

I Love it. Where is it? Where's this thing used typically in fluke multimeters? They use this circuit all the time. The Classic Fluke 87 here. Check out this.

I Don't have my poker, but there is a couple of transistors down in there. so I've actually use that for the I cut three input clamp in. Okay, let's have a look at another one. the Fluke 3000 meter.

flip that open and over and so there. Check it out. This actually has two parallel configurations of those for extra power dissipation, but this is quite handy to use these. The very first impulse are clamping response and used for these thousand volt a Cap 3, which I believe is eight kilovolt impulses, so it clamps those quite nicely a short sharp.

They're not high power dissipation, but they're okay and you might reuse these elsewhere in your bill of materials. So very handy to reuse parts. so there you go. That's a common use for those, so I hope you enjoyed that tutorial.

Now let's get back. It wouldn't be a thousand video if we didn't have a whole bunch of scopes. So what I'm going to do here: I'm actually generating. Let's do a quick review comparison.

I'm generating a 500 micro volt RMS signal and we've got the classic Tektronix triple to five analog scope with 500 micro volt per division range and there's the input signal. Now let's actually compare this. so we comparing the noise across several different scopes. now I've actually frozen and captured this.

Let's have a lot of Keysight 3000 here. You'll notice this is not a true 1 millivolt per division scope. So we're getting a whole bunch of quand horrible quantization noise on there that is just absolutely awful. You wouldn't want to use this scope if you're doing low signal work at all.

The Tektronix Mvo 3000 this one is a real worried. Look at the amount of noise on there. Look at it. You'll see that other scopes are much better.

So this is only one Billy volt upper-division minimum, but there's a lot. By the way, this is a one mega. It's sideways and all the Scopes are set the 20 megahertz bandwidth limit and the same memory depth of 1. Meg There's no averaging or anything else turned on.

So yeah, the Tektronix MTO 3000 Really? Luisi I Don't know where that's coming from and you'll see that in the contrast of this. Rohde Schwarz RTB to double a 4. Check it out. This is 1 millivolt per division.

But and this. is a 10-bit ADC But look how nice that waveform is. Absolutely beautiful. Low noise, Awesome work.

Rohde Schwarz The Hey made one up here. one milli volt per division and that one's got a little bit of noise on it. But otherwise, the freezingly clean result on the Hey Meg / Rodents Quartz the new Keysight 1000 X-series scope. This actually is supposed to have a better 1 millivolt range, but as you can see, it's very similar to the Tektronix so there's a ton of noise on there.

Not a great result at all. The Array Goal 2000 Series: Let's have a look. Once again, there's some higher frequency stuff on there. this has supposedly a no.

It doesn't have a true 500 milli volt range because you can see some quantization our amplification on there like you can actually see. Just not as bad as the keysight, but still bad anyway. The Teledyne Lacroix 1 millivolt per division. What a bad response.

A fairly clean waveform. everyone's favorite there I Go 1054 Z or not as a 1 millivolt per division range. Very very noisy. Not the noisiest as we'll see, but still not a great result.

And then the new segment 1000 X-series that supposedly has a true 500 micro volt per division range and it's a pretty good result. Fairly clean look at that. You can see some noisy details on there, but that's an excellent excellent result from low noise measurement with a true favorite of microvolt range. And then ah, this.

GW in stick. This is the worst of the bunch. Look at that, that's just horrid. We're like let's just not even go there and the oh one as a 12 a 14 bit converter, but it's actually only 12 bits at the moment and what we're looking at is a 12 bit.

The 8 bit is a little bit. it doesn't show the detail in there, but it's still pretty clean, so that's actually an excellent result on the old one. Very nice, but it's only got one milli volt per division, so there you go. That's just a quick comparison of all these different scopes.

Hope you liked that. and I'll leave that set up and do some more tests on that in the future. Now everyone loves hair downs on the Eevblog and I've got something special. Let's check it out, will? You might have seen this on a previous video which I'll link it down below where I did the Channel 7 TV Transmitter teardown.

This is the 300 watt amplifier that transmitted the analog TV signal in Sydney for about 20 years. This one 300 watt. So as I said, this one was the preamplifier. A 3-hour what preamplifier for the video signal and also to use the same one.

Might have even been this one for the audio. so the audio went out of 300. Watts The video went out of several hundred kilowatts. It's got to phase a shift input here so that you can parallel these things up and tweak them for the same phase so that they load equally.

but that's just an input output and overload indicator. So let's take a look inside this baton. Yes, we have the schematics. You're ready for it.

Oh yeah, the RF aficionados are wetting their pants right now. Look at this thing. Ah, I have to do a detailed teardown. This will be very short, but look at all the rigid coax lines here with that little stargates inside.

Look, look little rigid coax penetrators. Here's the power supply. It operates off 28 volts DC system supply. and let's take a look at the topology used in this thing, shall we? And I'll take you briefly through.

Oh by the way, I do have a schematic. I'll linked in and down below for those playing along at home. Now the input signal comes in down here and it goes into a limited circuit because you don't want some feeding in some input signal that then blows up your air plethora. Now you know, couple of million people in Sydney can't watch their TV signal so it just clips and limits the input signal so it doesn't damage anything else.

And there's a phase adjust Now goes into a circulator which I'll explain shortly and then there's a couple of pre amplifier transistors over here and then that leads up into another circulator which then goes into two circulators which basically split the signal out like this into two separate channels. So there's actually two power amplifiers in here to complete separate stages like this: I Believe they do this for redundancy so that if one blows that, the other one still goes and they can't affect each other. It recombines in a circulator and then comes out down here that's tapped off for an overload indicator display like that. Beautiful now.

I Promised to briefly mention circulators, so let's give that a go. Let's have a look at these circulators down here. What a circulator does. It's a passive device that uses ferrite and it basically does RF power protection.

So it basically circulates the power through to a dummy load here. So some idiot shorts the output of the antenna here. Then what it will do is automatically dump all the energy into the load. Like this: the load is internal.

Well, no, it might be external, but it it dumps it into the load instead of blowing up your transistors over here. Very, very nice. and you can probably see the power resistors going to be under there near the output circulators from combining. There you go.

It is very, very nice. A bit of kit and I'll have to do a more detailed teardown on that, so hope you enjoyed that now one that we all like an Eevee but hopefully is debunking. So let's have a look at a debunk, shall we? Tada right? Which product is going to win the Product of the Century award Because Century is only 17 years old? So oh, it's a lot of contenders. Isn't there? you know? Batteries, a solar, freakin' roadways, and all sorts of stuff.

But this one I think takes take the sheer number of the dollars that have been invested in this and just the sheer ridiculousness of the idea. let's take a look, shall we? The winner is Drumroll You Beam. Now if you haven't seen, I've done a blog post two years ago debunking the UVM concepts as have many others, including the former Vice President of Engineering at U. Beamers even debunked this is how bad it is.

Okay, now if you don't know what it is, it is ultrasonic wireless power transfer. It's like Wi-Fi for charge in Whoa! That gets all the investors juiced. I've done it. Yeah, it's going to be the energy infrastructure of the future.

Oh by the way, twenty eight million bucks. They sucked out of the investors for this boondoggle. Unbelievable. They reckon it's safe.

They reckon it can be used in buses, trains, planes, cafes, gyms, hotel, then stadiums. If we can sit in a stadium. If I had my phone. Here it is.

sit in a stadium and big huge staying phone magically charges. What's that? Yeah. Unbelievable and all power. TVs Without wise you can see TVs in the middle of the room.

These magically work. Whoo Pixie dust. Um, now They were very secretive for a couple of years and then they finally revealed some stats. I've been working on this for like five years? Okay, and they finally said, oh, we can do a four meter radius and At and we can charge a phone at one point five watts.

Yeah, it's not nearly as good as USB can do. Especially USB See these days, you can wonder why anyone needs wireless charging at all. Really, with how fast modern charges can actually go. And they release their specs for how much what their transmit power is.

a hundred and forty five DB to 155 DB at 60 kilohertz SPL sound pressure level. Now we'll talk about that in a minute. now. look the power.

With ultrasound in air, different mediums of different things, it drops off with a square of the distance approximately. Yeah. Three Eub per meter. Nice round number.

That's actually what it kind of is in here. So it even if you're a 1 meter away just with the air alone, no other losses, you lose 50% It's only 50% efficient and so it 2 minutes. The efficiency is already 25% right off the bat before you start including. and that's assuming 100% efficient transducers, no nonlinearities at 100% focus.

By the way, if you have, if they've got an array like this, it's actually slightly bigger. Bit bigger than this, then they can actually turn on only parts of it and get a smaller aperture size and that will have a better, naturally different natural focus distance. And I believe with roughly the size of the transmitter they've got, it's about maybe a meter and a half. Guesstimate is the natural focus distance so that it's been forming as well.

So they can do electronic be informing to follow your phone. So they've got some very cool tech actually to locate where your phone is and then be inform. It's about a half second lag which you can see in their video. A full info.

Granted they've got some cool tech but let's just look on it and well actually let's not. This has to be sure. I could go into the numbers here. 145 to be 155 SPL is like gives that we can basically get maybe my estimate at a meter you know, 2 meters you might.

you can get that one and a half. What? It's not a problem and there's two ways to analyze. This one is with a continuous a fixed transmit power and the other one is with a variable transmit power where they change the size of that transmit aperture and pump more energy in to maintain 1.5 watts at every distance. for example, that's their figure.

If they could charge quicker they'd be boasting about it. but that's the best they could boast 1.5 watts. It's getting down towards trickle charging and it drops off is square distance, but it doesn't matter. This thing.

No, it does not violate the law of physics. Yeah, and yes, it does work. This thing can work. You can charge a mobile phone using ultrasound at several meters.

It is possible, but the efficiency is down in the single-digit percentage and in practice it's going to be possibly sub one percent efficient because things is affected by temperature pressure, which is altitude, humidity. There's nonlinear effects the saturation in the air because you're pumping in so much pressure, sound pressure level. the atoms just molecules to go and they can't do it like them, but they just die. They saturate poor little things and you know you can't get you reach a saturation point anyway.

we could go through there is it doesn't matter, The numbers do not matter with this. I'll show you a whole bunch of stuff on another whiteboard where I've got some major points that just blow the scene right out of the water. Let's go. And by the way, I'll link in a video of the CEO of you beam I challenge you to try and sit through all 15 minutes of it.

It's really bad. Take it away. Meredith for each technological hurdle deemed insurmountable by the experts, I Would spend just a few hours thinking about the problem from a variety of approaches, so I was able to solve problems when the PhD experts couldn't with just a few hours of really simple research. every single argument over why the technology couldn't work has been indisputably wrong.

This taught me to be skeptical of experts, but expertise represented a narrow way of looking at things. Engineers are inherently linear thinkers and tend to take a very binary approach to solving problems. As a non expert, I had an advantage because I could look at a problem from different angles because I just didn't know it was possible. By thinking outside the box.

by thinking around corners, you can out thank the top thinkers. And now eight months later I have four of the top ultrasonic engineers in the world working for me. We're working with me. It's going to work and it's going to be awesome.

And I can't wait to give the middle finger and smiled. All the engineers that criticize the crap out of me. This is why you been. It will never work on any ultra sonic charging technology.

Why it's not practical. Let's go to number one: the efficiency. It's going to be bad. As I said, if it's 1% I'll eat my tinfoil hat at 4 meters.

like give me a break. It's the worst efficiency charging technology by an order of magnitude on the market. And remember, it's going to be very bad for the planet. If everyone implemented this, the planet will be screwed.

Energy Usage Energy consumption is one of the biggest problems we have on this planet. You might know of the Energy Star legislation where it's actually against the law to sell products in some countries that have aren't very efficient, charges, mobile phones, and things like that. They need a certain standby power. They need a certain efficiency.

otherwise you no matter, cell in the Mips regulations, all that, some stuff. So right there off the bat, this thing shouldn't have even made it past the first concept. It's just the efficiency. Who's going to want this? It's just ridiculous for the planet.

Unbelievable. Anyway, Cost: The cost. You need hundreds of these transducers that can do 140 555 DB SPL in this thing. And for the transmitter.

Hundreds and hundreds of them. And you need maybe a hundred of them for a phone size thing. We've got like a hundred of these things on the back of a phone and these are already sold in massive volume. At seven for the automotive industry, this several dollars each, you might be I'll pick them up on Aliexpress for like 50 cents or something, but there's no way that Willy Wonka's transducer factory is going to churn out transducers of this.

You know, capability and efficiency anywhere near a practical consumer. Cost is just ridiculously so many of them. Uh, and it will compare that with a competition in a minute. Sighs.

How thin can you make these things? Really? You can't look at their design. They've spent five years on this. tens of millions of dollars in development. And they've got a brick.

An actual a big brick. which they you know you have to hold in a certain direction like it's going to be flat. On to the thing. There's a reasonably hold it like that crazy nobody's going to want that.

There's no way it's ever going to get soon enough thinner than a Qi charger that we'll look at. It's just right off the back. There it's gone. And safety and legality.

Let's have a look at that. But on their website it's all about safety. And but most countries actually have is a legislation or recommended safe levels of 110 DB SPL. So UB is up to three thousand times higher than what almost every country recommends as a safe limit fault.

Restonic And look, it's ridiculous. Don't let them convince you otherwise. On the website, it's just and waffle Now five. And this is the facepalm.

This is where it should never have made it off the bloody napkin you come off the idea or ultrasonic phone charging. Okay, let's on the back of the napkin. Let's see how pretty feasible this is. People put and use phones face up, on a surface so gonorrhea, receiver transducers on the back and in a cafe.

which is one of their big usage scenarios. Things not going to charge at all Zero. It's ridiculous and people hold them in their hands at odd angles like that. Once you tilled it like that, you'll notice that they hold them in there demo perfectly.

Like that with their fingers. Wow Course it's going to work, but when you note people hold them like that at angles and wince their hands on the back, you've lost half your transducer area. Anyway, it's ridiculous and people store them in their bloody pockets. Bloody modern, huge phones barely fits in my pocket, but they store them in their pockets.

their bags where it's absolutely useless there is right there Off the bat should not have been funded or made it off the back of a bloody napkin. It's just not a practical charging environment. Let's compare it with the competition, the Qi charger. My phone has a Qi charger already built-in wireless charging.

It's already built into most on good.what on the phones on the market? it's called Qi and it's already built-in and very efficient. Upwards of 50 percent efficient. Pretty good order of magnitude, better than you being will ever be. And its best.

And it's cheap. You can buy one of the charging pads for five bucks on Ebay, delivered, delivered to your home like it's been. There is no competition. There's no way that Willy Wonka's transducer Factory is going to churn out these things for anywhere near the cost of what the Qi charger and the fitness of a Qi charge with the coil in there tiny little sliver of a coil and just the controller charge a chip to go with it.

if it. there it is - every one of these points is a showstopper. It's just dumbest idea ever. Anyway, that wins a product of the century, decade, year.

Whatever. it's pretty dumb. Anyway, let's wrap it up so that's it. It's a thousand episodes.

hope you enjoyed it. that was pretty much done I think it was done in a single take and that was the idea. Bit of a medley or everyone's favorite segments I could have done it in more Tudor I'll play around those scopes a bit more. that amplifier teardown is a bloody Ripper it's a Bobby Dazzler so it needs more detail on that.

But thank you for everyone who has supported me from day dot when I uploaded I'm just a silly little idea I had for a video blog onto my personal YouTube channel posted on Oz Electronics and I don't know I thought maybe a thousand people had watch it but I got a thousand in the first week or two and it's been grown. Two years later, this sitting in a lab off-the-cuff doing this of a crap is my full-time job has been for six years. so thank you that everyone who said subscribed viewed me summer viewed every video from day one. Awesome work and everyone on the forum and everyone all my advertisers who've kept me a financially afloat and all that sort of jazz.

And yeah, this is probably Video 998 officially numbered an 1100. I don't know I've done a crapload of videos. it's kind of thousand in the title. It's pretty official so there you go that wraps up.

Thank you very much and hope you enjoyed it. Catch you next time! Is it done? Whoa. Whoa. Single tape You.