Hi Welcome to everyone's favorite segment: the Mail bag. We'll get straight into it. First one here is from Chris Peters in Danville California There you go in the United States of America that crazy Aussie block. that's where you need to send stuff and we have a t-shirt, pen and keychain.

but it could be more interesting than that. It's got make Air 2013 on it. So are these items from uh, the Make Air which of course I couldn't get to. Of course that would be the Bay Area make aair.

The biggie, although the New York ones on uh in a very shortly I think and uh, let's have a look cardboard stiffener we have a letter. we look at that. What t-shirt have we got? I Love shirts Black? All right. let's have a look.

oh look, it's a M There you go. Hang on. haven't got a wide enough zoom on this thing maker 2013 Look at that. Beautiful! Is that the official um makeer Fair t-shirt or I I don't think so it hasn't got make aair on it look Ive got a goodie bag, a candy necklace oh my goodness I haven't seen those since I was a kid.

a swirl pop and keep C and make on Texas Instruments cool. So this is obviously the uh goodie bag I don't know, did everyone get these when you went through the door? I'm uh, not sure anyone who. well I'm sure he'll tell us I should read the letter shouldn't I I mean this is ridiculous hi Dave since you couldn't go to Make Air I thought I would send some make air to you Awesome! This was the first time he attended. Very surprised how big it was.

110,000 people over a two-day period last year. Fair. So huge, so many different time. really difficult to describe.

Yep I know. Anyway, we've got the make Aair Sydney coming up on the 24th the first ever. Sydney uh maker. there's been one in Melbourne before and uh one in Adelaide but not in Sydney on the 24th of November and I'll actually provide a link uh down below for uh submissions.

If you want to get like a table or display anything or participate in make Aair Sydney then uh, the link will be down below. Uh, you made a point to find Jeff uh kaiso nice talking sign signed his make a fair bag hi to Jeff Hope you enjoy the te shirt. My wife even added a lolly for you I Hope you enjoy it. Awesome! and uh Christopher is from Faultline Audio.

net. Thanks very much Chris Got ourselves a make keying I'm an imp ventor keep K and make on Arduino I have supplied a little button I've got a makeup pen with a little ruler on it, inches and millimeters. that's surprising for you Yanks and I've got make special issue Woohoo! Want to make a Tesla coil? I've never actually had Make magazine. so there you go.

Architech Oo inside make Aair Brilliant! 42 awesome projects. Definitely there it is. There's the make aair. um, fold out.

definitely going to have to read that. Awesome! And it looks like we have a sticker pouch as well. Like a um a whole swag of stickers. goodness.

Yeah! Wow! Arduino blah blah blah. Oh technical. Illusions There you go, there's Jerry projected Ari Game systems fantastic and what on Earth is that it's a Fishmobile? Oh goodness. Well there you go People who want to scan it, scan it and you can check out the fish.

Mobile car has over 300 lb of batteries, computer, 31 custom circuit boards and 5 mil of control system wire featuring two Sol Conductor Six different singing dancing fish and lobsters perform every Opera to punk and rock. Check out the website. oh that's gold. it really is.

So that is a huge swag. Thank you very much! Chris makes it feel like I Went there awesome I'll get there one day. Next up we have a book from Cooko Press in uh the US and I Haven't heard of Cooko Press before but I think I might know what book this is if it's the one I'm thinking of let's find out it invol actually it's very it was released at the Uh Make Affair so let's have a look uh it is going to be a come on there we go. No it's not the one I was thinking of No wonder I Haven't heard of uh Cooko Press because um I thought it was uh the make a book that um I am in and which I will provide a link down below.

Um, there's an interview with me in the book along with Uh Jerry Ellsworth and a whole bunch of um, uh, other uh, people in the community. which will you will know so it's not that book Um, the Dog Barks when the phone rings. An engine's guide to solving problems A More Problems There's our engineer Token engineer become a better Problem Solver Look at this. This is fascinating I Never heard of this one.

The transition from engineering school to real world problem solver can be rough. Suddenly there is not just one correct response to a problem. There might be an infinite number of correct Solutions where some are simply better than others. Some problems are so layed and twisted that the solutions seem absurdly complex and it's written by Bob Schmidt is who is an electrical engineer with four decades experience in Hardware Software and Systems Designed with over a dozen patents.

He has solved problems as an engineer, as a manager of global teams, as an entrepreneur o that evil word Bob also shares more Parables for engineers at pretty Good Problems Solver.com Good on you Bob And we got a letter from Bob in Clos Please find a copy of my book. The Dogs Bark When the Phone rings. An Engineer's guide to solving problems. This book is really intended for engineering students and recent graduates.

Awesome! Um, your experience will probably make most of this book seem obvious, but maybe you will find a few laughs in there. I Send this with full understanding. You're welcome to do anything you like with the book. I Certainly will read it first, of course, read it or not.

Comment or not. give it away. Parking on a bookshelf? put it under a wobbly Table leg. anything you like.

Believe that my publisher has enabled distribution in Australia through Ingram. So this book should be available in Australia sometime in September but is it available as an Amazon Kindle or other electronic download? That's what I want to know? I'm a bit of a Kindle uh fan these days Anyway, thank you very much Bob at pretty Goodrs Solver.com and the first page I opened it up to talks about sensitive nodes. Awesome. Yeah, that sort of stuff.

Practical stuff you don't learn. Um, no. Do I mean circuits or noes that easily get their feelings hurt by criticism? Do I mean parts that intentionally respond to touch? No, Um, there you go. How the heck do I know what a reasonable measurement is? Ah, this sounds.

This sounds really quite neat. Tear Downs As a debugging tool. There you go. Fantastic problems.

Tear down exercise. Let you remeasure the performance and visual component. Woo! It's all in here. instrumenting software.

Let's go to the index. Oh, here we go. Dave Best wishes for your continued success. Thank you very much! Bob Bob's your uncle Bob is my uncle, but not this.

Bob and there's our index. Looks quite good. Barriers to good: It's all about communication, communicating clearly. What don't you know? everything? When you leave school, that's for sure finding the stuff you don't know.

Experiments: Deb Bug by division stimulus response testing Oh excellent. If I could see it I could fix it. Measurements, Instrument software tools, intermittent problems. Oh, there're a bastard.

Nothing like an interment problem and good red hairing to go with it. Um, how to think? Part One: Pretty important. How to think? Part Two: It was so important he added two parts. The great idea does not have to work to be a great idea.

Very true. Study your mistakes Yes, fail is you know learning is all about failing. So there you go: 243 Pages Excellent. What's the index like a A? It's pretty sparse.

It's pretty sparse, but you know. Anyway, you know this is a book that you just read from cover to cover. You don't sort of. you know, uh, reference individual bits.

Oh, where's noise floor? You know you're not going to look up noise floor perhaps. So it seems like a more, uh, conversational, uh style book that, uh, something like uh I would write so yeah. I'm definitely going to enjoy giving this one a read. Ah, dead trees.

Love it. I Like this little bit here is one of the most important things I can teach you. There is a giant difference between customers and investors. If you do most things right, a customer will not want his money back, his or her money back.

In fact, the better you do things, the more likely the customer will give you more money. Of course they will. In contrast, even if you do everything right, an investor wants all of their money back. All of it.

No all of it times 100 Clear enough. Got it right? Bob Next up we've had one I've had sitting around for quite some time from Uh Worth Electronics and uh, it is a Um Energy harvesting kit to go. So beautiful I do uh I do like energy harvesting so I do have an energy harvesting kit so um I can't remember who it's from I I'm pretty sure it's not this one. um and I've had that for I don't know for four years or something.

they had it for quite a long time so um I may have to. uh oh this one. Oh, Linear Technology with Energy Micro. Ah man, this one is serious.

Look at this from Worth Electronic Design Kit Energy Har Harvesting solution to go linear Technology Energy Micro. It's got a whole bunch of stuff. Complete solutions for harvesting energy, energy management, storage, blah blah blah blah blah. There's the auto code if you want to check it out.

IC 7485 I'll provide a link as I do to all stuff and this looks W comprehensive Look at this. We got a pelia check it out which can and we've got a um another giant gecko. Fantastic can always do with a giant gecko. we've um, seen that featured on the blog before.

that is an excellent uh little board I like it as part of the watch. um uh thing that I did a while ago. Anyway, the um the sharp low power LCD display got ourselves a a solar cell and uh, what do we hook onto there? is that a uh piso power I don't know demo Circle board multisource board. so uh, converting thermal energy into uh Power that's basically what we're uh doing there.

so um, with that uh with that Pia device on the uh on the heat sink stuck onto the board there. So we're going to have to check out what energy harvesting chips actually used on this I tell you what, they've gilded the Lily on this case I mean look at that's just sex on a stick. Look at that custom foam. um insert oh man jeez, they really have gone to town there and I just love the smell of this rubber.

Oh yeah, smells like a pair of thongs. Whoa look I didn't do anything and uh my board. My giant gecko board just spr rung to life. There we go and uh I don't know what's that uh Fahrenheit that's temperature and uh that's a Fahrenheit and 22.2 de see it's jumping around a bit but there you go.

Um, it's obviously getting power from. is it getting power from the solar cell or from the thermal? or both? Perhaps multiple sources? I Guess that's the idea that they want to demo here and I haven't actually uh, looked at it yet but uh, we're looking. looks like we got different energy harvesting chips. This is really quite neat.

It looks like you can evaluate the different types. Oh beautiful. but uh, by default I didn't touch anything and it just, uh, just sprang to life. Fantastic! I'm covering that solar cell and it's slowly dying.

You can still, it's just hanging in there, still just got enough power, so clearly it's getting most of that or all of that from the solar cell hasn't uh, hasn't sprung back yet. but uh. anyway, we can still operate this thing. this switches between I mean that LCD is getting pretty dim there, but uh, it's still operating so we can switch between Uh Fahrenheit and Celsius as the main display there.

Excellent. And what we've got is uh, four different Uh energy source circuits here you can set using this particular Uh jumper here. One's for the Uh supplied solar cell, one's for a diode, uh, voltage drop, or solar cell. the other is the Uh Teg powered Energy Harvester which is T stands for thermoelectric generator which is of course the uh, the Pelia device up there on The heat sink.

And then we've got a p Electric Energy Harvester which can, um, hook up to an external p Electric uh element. It's not on board, but that's what that connector up there is. you just connecting your particular uh, you know, poo thing, shock, vibration, all that sort of stuff. or if you're walking or something like that, you know you can generate, um, a tiny amounts of uh Power And this is what energy harvesting is all about.

And in this case, they've got some uh storage caps on the back. just some very high value uh, ceramic um SMD caps on there just to store a bit of energy. but uh, there you go. That is rather neat.

and uh, the documentation here which I will uh, provide a link to this uh uh website. but as you can see, these are the different devices. LTC 3105 for the solid cell. It tells you all about the micropower monolithic booster.

got the Pia element and what? LT C Parts the P element. They're all LTC uh energy harvesting uh chips. but there's an inductive energy uh Harvester Fantastic! So there you go. This is a really nice little starter kit for energy harvesting.

It really is fantastic. I like it and I just checked the price and yep, it's not cheap folks1 99 but um, you know, if you I mean it's all there. um, all the different types of energy harvesting. So if you're really serious about experimenting, then uh, it's worth every set.

I Mean the giant gecko board alone is worth about 80 US bucks or something like that. by the way. um, Energy micro um were bought out by um silicon Labs so they're not no longer Energy micro. Oh boohoo, we've had them on the amp so this kit craps all over the other energy harvesting kit I've got.

which is you know, just got one particular type. pretty ordinary I think um, but yeah. I'm definitely going to have to do some videos on energy harvesting and well, if you want energy harvesting videos, uh, please leave it in the comments, let me know and encourage me to actually get off my ass and do some energy harvesting videos cuz there's some great you know, really low power measurement uh stuff you can do with these uh, energy kits which you know I really can't get into to uh doing that sort of stuff in a mail bag. It'll uh, take me quite some time to uh set up those things and uh, perform the experiments and of course worth Electronics Aren't shy about telling you what parts on all this system are theirs? Look at this.

They got the USB connector of course the battery holder. they got the Caps they got uh, looks like what's that? a little lead or something and they got the switches and they got the inductors and they got the connectors over here and the pots and a man the connector H caps. They do everything everything so thank you! Very much Worth Electronics That is an awesome energy harvesting kit! I Don't think you can do much better than that. Now of all the linear technology chips used on this thing, uh, the most interesting by far is the LTC 358.

The other ones are just basically, uh, just run-of-the-mill Well, not run-of-the-mill but uh, you know, pretty good. Uh, low power? uh, low voltage boost converters? That's pretty much all they are. Like the one for the solar cell for example. Um is is just your average boost converter, but this 358 Um is quite a useful energy harvesting device.

And let's actually, uh, take a look at the thing here. Um, it's specifically this is for the P electric energy input from that uh terminal because we don't have a P Electric element on the board. Uh, we have to add that separately. but it can do not only p Electric but other sources as well.

So let's take a look at it. quick look: 950 Nano Quiescent current Um output it with no load on the thing. 450 nanoamp input quiescent current in ultra low voltage lockout mode 2.7 to 20 volt input operating range. So this one specifically doesn't go down to low voltages.

but as we'll see, it, allows us to do quite a few useful things. And it's got an integrated Uh Fullwave Bridge rectifier in it, hence the ability to rectify the Uh AC coming from a P Electric element and it's pretty beefy. up to 100 milliamps of output current. Of course, in P Electric mode, you usually not going to be generate that kind of stuff, but it's a generically useful chip and you can select the output voltages all of you know 1.8 2.5 3.3 3.6 Very nice.

And of course it has a uh high efficiency Uh Buck DC Todc converter in it. It's got input protection and under voltage lockout. Unfortunately, it comes in a pain in the ass 10 lead Dfn package. Evil.

But anyway, this is how simple it is. Here's your here's your P Electric element here. hook it up to the two pins, nothing else required, and just a couple of Uh caps here and an output inductor and that's it. and the output capacity here.

This 47 Microfarad 6V Of course that can be like that whole storage array you saw there before of all those chips. I'm not sure what values they were probably like 100 microfarads each or something at at 6 volts. or you could use a super cap for example there. and uh, let's go down and have a look some of the useful applications.

We won't worry about the graphs and stuff like that, but here's the fullwave bridge rectifier Basically, so it's just a bridge rectifier with, uh, a separate input voltage, so you can actually use it as like a dual Source uh converter there and and just digital control to set your output voltage. So nothing too fancy. But what that allows you to do is if we go down the bottom here, here it is. Here's our, uh, just a regular P Electric one as we saw before.

Nothing much doing there. but then we get into some of the other applications. Look at this. This is a dual rail uh generator so you can share the same petric element of course, just in parallel across both chips.

so you can generate a 3.6 volt rail for example, and a 1.8 volt rail showing there. And uh, then this is, um, an example of the Dual source with energy harvesting with battery backup. So we got our external 9volt battery there. You need a reverse protection diode of course.

Otherwise, because as we saw in the internal diagram up here, where is it? Here we go. There is nothing, uh, stopping the P Electric element, reverse charging your battery on your VIN over here. so you obviously have to put that series diode in for any uh, external power source and down here. this is quite neat.

Look at this. Um, danger. Will Robinson Um, high voltage. You can actually just hook it up directly to the mains like that with a couple of series resistors.

And because it's just a full- wve brid direcor fire, then you can just use it. Um, as a nonisolated. of course, that's why they put all of the you know. danger, danger, Danger.

Use Isolated. uh, uh, isolation Transformer when testing blah blah blah. So it's not an isolated means isolated one. Um, so just be careful with that.

but that is quite neat and it accepts I'm not sure what frequency range it uh, accepts over, but apparently it is uh, uh, quite broad of course. and this one is quite neat. Electric Field Energy Harvester Look at this. it's just telling you.

Basically, um, just to get two copper panels there and uh, just place them 6 in away from a fluorescent light fig and that's going to generate enough power to you know, charge up your super cap or charge up your lithium ion battery or do whatever uh, you want to do. And here's an example with a super cap of course, it being used with a solar panel here. so you can actually feed the solar panel via a series resistor into one pin of the P Electric element because it's just a diode. Bridge Of course you can feed DC into there as well.

and uh, then get your output voltage and the super cap of course stores everything because you don't need any. uh, reverse diet on there cuz that's or uh, series diet in there to prevent uh, back discharge into the chip because the chip just shuts down when uh, it, it does that for you. effectively. it just shuts down when there's not enough input voltage to charge the super cap.

so your super cap can then continue to charge all your circuitry while this chip shuts down if your light goes away, for example, with your solar cell, and then once again, uh, you can hook this up to the thermoelectric generator. So this is a pretty versatile chip. It accepts with that diode bridge in there accepts pretty much any Source you want to throw at it. I really really like this thing.

It's a shame. it's uh, not in a you know, a nice S So8 package or something like that would have been nice. but uh. anyway.

I like it and we got another one here from Jamco Electronics who had a couple of uh uh, sucks of the Sav On uh, the mail bag here so let's pop it open. it's opto Electronics what does that mean I don't know. um, obviously a kit. uh, Jamco do kits.

so uh I think I've got a couple of previous ones I still haven't uh assembled? I'm going to do that one day. A lot of people keep asking for um, you know, can I do like kit assembly videos with all the kits I've got? well maybe, but uh, you know what do I do? What's uh, so excited about? uh, you know, seeing me assemble kits I guess you know? um not very exciting at all. I suspect oh oh no. hang on I'm going to have to just slice the buggery out of this thing.

It's obviously when you know how the end just pops off a it comes electronic do-it-yourself and components. Check this out! once again, nice little Jazzy case right? Dave Thanks so much for for requesting our Sky Rider kit. Oh did I Um, please let me know if you have any questions. look forward to hearing from you.

Thank you very much! Um Francis it's one of those um wands by the way that you, uh, just hold. you know it's got a microcontroller on it. These were all the rage. Uh, years ago? they're still quite funly.

It's a good beginner kit and uh, you can experiment with that firmware. so it's basically just a microcontroller once. this one a pick or an appil or whatever and you basically got some leads on there and you put them on and you wave it like that and you can get a message on Via Persistence of vision. And the good thing about this kit is that it's all through Hole.

There we go. They even give you a proper uh, socket through hole, leads, individual resistors, all in individual little baggies like that. Fantastic. and uh, a battery holder.

How do you get a three? How do you stick the battery? I Guess you sort of. oh yeah, it come. you know, then it makes it into a grip like that. That's all right, right? Nothing wrong with that.

Probably don't have a voltage regulator, they probably just run it off. Um, the three AAA cells or whatever. Um, but yeah, I mean this is one of the things, right? You know people ask, oh, why don't you do SMD kits and well, you know this is dropped it. This is the reason.

Um, because it's bad enough with through hole. you know you've got a bag, individual resistors, and individual caps and stuff like that. Imagine a complex kit with all SMD Parts which basically don't have any labeling on them and you got to cut them off the individual strips. and oh, just far too hard.

don't even want to think about it. And they got reasonably detailed, uh, beginner instructions here with you know, step-by-step photos. I Mean you know if you're relatively, uh, well, if you've built a couple of kits, you're just going to hoe, uh, straight into this thing and uh, get the sucker working. Yep, pick a 16 C84 Classic.

It's not even the F84, it's the old C84. This must be, um, quite an old uh kit. then to use the C84 anyway. there you go.

Um, I'll provide a link down below if you want one of these. Sky Riders They are quite fun. Um, not sure of the price, but it'll be linked in down below. You can get it from Jameco.