Old school mailbag.
SPOILERS:
00:00 - Old School Mailbag
01:09 - TOASTY Quadcopter ESC
08:07 - The best XMAS Tree LED light yet
https://www.elimo.io/
11:26 - Kaiweets ST600Y Multimeter
https://s.click.aliexpress.com/e/_ALpSqJ
16:00 - UK Radio Teleswitch
Protocol: http://downloads.bbc.co.uk/rd/pubs/reports/1984-19.pdf
Forum: https://www.eevblog.com/forum/blog/eevblog1457-old-school-mailbag/
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#ElectronicsCreators #Mailbag

Hi Welcome to everyone's favorite segment: Mailbag. Yes, I'm going old school. just behind the camera with the magic hands here and the big Croc Dundee knife. So let's get into it.

Why am I doing this old school? Well, I'm just too lazy at the moment to set up the main bench. So yeah, whatever. Anyway, thank you very much Manuel Koller from Zurich in Switzerland. Hold on all my viewers in Switzerland and I'm opening this one first because it's too sir.

Doctor Professor Grand Master Jedi Dave Jones Magic Smoke Po Box 7949 2153 should be Northwest, not Balkan Hills. but it'll get here anyway. It's they just changed the name of it anyway. New South Wales, Australia, not Austria.

If you want to send something into the mailbag, let's have a squiz shall we? So this is yeah, I forgot how hard this is, but did I used to really do this behind the camera? Because this is kind of like I've got to get to the side. Oh no, this is just don't know. Oh, I forgot the back content. spoiler, charcoal, copper, tin, damaged electronics, batteries, and magic smoke not included.

Damn it. I'm gonna have to get one of those um, Ibm cans of magic smoke because I'm all out. and uh, that was my knife hitting the tripods. All right, no workers.

Um, yeah, I'm all out. so I'm gonna have to get the magic uh smoke can from Ibm. The rarest henstick. You know how much they go for ebay on ebay these days? Geez.

Anyway, what do we got? Got a note? I bow before the Great Dave we are not worthy. We are not worthy. We're not worthy. We're not worthy.

We're not worried. I'm sending you a motor, an Esc from a Flying Quarter. Oh, I bet. yeah, the magic smoke has escaped.

Uh, which has gone through meltdown? Uh. check Youtube for Rhoda Riot and Final Glide Oz Aussie for more about the topic. Even though properly and insulated with two heat shrinks tape and foam pads, the Esc bursting smoke during a gentle first flight outdoors? I don't know. It has some like um, shoot through or something on the transistors in it.

I do. You know? Anyway, I don't know if you know why they are magically burst into smoke. Leave it in the comments. Oh, hopefully I get the full smell as well.

So there's the operating specs for those playing along at home. Thank you very much. Manuel from uh, Switzerland managed to get oh geez, that's it's that's one sick puppy. Um, all right, let's have a squeeze.

Yeah, no more smoke left in that hang on? Have a sniff? Oh yeah. Yep. Yep. I can still smell it.

Thank you very much Manuel for still including the magic smell even though the magic smoke has escaped. So that's just the um, outer, uh, sheaf thing for it. I don't know what the metal, so oh, is that like the top heatsink cap kind of thing? Those windings look a bit black, don't they? And the board? Oh oh yeah, nah, that's one sick puppy. You can still see some part numbers on there.

It's upside down so all the electrons are going to fall out. Um, there you go. You can I can ju I can't really read those too well on the camcorder screen, but I know it's in focus. Uh, because I've got focus peaking on my camera.
All these little red lines show up on my camcorder screen, which show me that everything's in focus. Mostly seems to be around this top corner. up here. There's a 78m, 78, one two that looks a bit toasty, doesn't it? Wow.

Ends up if you're into Quadcopters and uh, how many of these have you seen? I believe it's uh, relatively common to, uh, you know, get a blown Esc or are they just getting better these days? Um, let us know in the comments down below. All right, let's have a squiz at this under the tagano shall we? I've actually cleaned this up with Isopropyl. believe it or not. So there you go.

you can see the bottom transistors. There are international rectifier jobbies. so and it's a big name brand seven Double Four Zeroes. and if we go over to the battery sheet, these are strong.

So these are 40 volt 90 amp uh, Jobbies And like you know, as you'd expect, these are designed for brushed motor drive um applications and they obviously have not failed. Um, but you can see the three on the top. Um yeah, the magic smokes escaped. They are completely snotted.

This poor sucker here has just spilled all its lollies. Uh, the wheels have completely fallen off the billy cart and the Pcb is just absolutely like burnt to like charcoal crisp. Oh my goodness. Um, that's terrible.

Muriel. Wow. It got so hot. These chips here are just like rotated.

They've just melted off the pads. That's how hot this sucker got and you can see like there's a is that a pad? No, that's just uh via stitching over there and it's just wow. That is completely Gonski. Ah, that's just beautiful.

Anyway, so yeah, the top transistor array is gone. so that would be the positive uh, transistor, the positive rail ones and the negative rail here. So if we have a look at that, I just search for because I don't know the model. I just searched for a generic est esd esc schematic which is electronic Rsp controller and this one here which is Electroneubs.com This is a very nice representation here of what we would have here.

So we've got the three N channel uh ones on the bottom which are okay um and the three P channel ones on the top. I don't know if this has a gate driver no these gate drivers that come, they wouldn't be discreet transistors here that just come directly from the uh driver chip or whatever. But anyway, um yeah, the three P channel ones on the top looks like they're all fried. So what's likely happened here? So there is no what's called, uh, shoot through here.

which is what I might have, um, suggested, uh, before. which is where like both transistors briefly turn on and then boom. Current flows like right through from positive to negative rail. But in this particular case, all the top ones are fried.
So obviously something's happened in the motor, the wire, and something else that's caused a, uh, grounding, um to happen or excess. you know, current and they've just all burnt out. The poor old, um, top P channel job is there. So yeah, what? what? Um, complete and epic fire.

I think that was there another capacitor in there, That's just Gonski? um, but uh, that's that's gorgeous. So yeah. anyway, what would cause that? I don't know. Um, leave it in the comments down below like you know, the motor could, um, the bearings could seize up there.

You know the rotor could stop or it's I don't know what. I don't know. If you're a Quadcopter aficionado, I'm sure you, uh, destroy many of these things. I've heard many of these, uh, the wheels fall off the billy cart and the Esc's uh, fail.

But apparently this wasn't under rated. You know the motor was 20 or 30 amps and this was rated for like double that or something. so there was a decent margin in there I think. um, so I don't think it's rating so I don't know if it's a no name or brand, but anyway, it uses genuine, well, supposedly genuine international rectifier and they they're fine.

The top ones. Oh, that's great. Thanks for sending that in. That's awesome.

And um, for you motor aficionados? Yep, so did something happen in there and that's what caused it? I don't know. Um, don't know what the deal is. Interestingly that they're on opposite sides there. There's all your charring over here over on this side and charring on this side, but these, these are relatively untouched, so I don't know.

There's a bit of symmetry to that. Is that just kawinkidink? Or is there or is there something physically to that? I don't know. Leave it in the comments down below. I'm not into my Quadcopters and Motors cool huh? Thanks for sending that in.

That's awesome. This one comes from the old Dart courtesy of her majesties. Thank you very much. Uh, Simon Martin for sending this in from London.

Um, it does have a Merry Christmas on it. Yeah, these things have been sitting here for a while. I've been on holidays. you know the usual story and it's yeah.

I know it's like almost mid February now. Isn't it unbelievable? Anyway, um, really awkward to use behind the camera. Look at the size of the bloody thing. it's enormous.

Anyway, let's have a squeeze. Oh oh, I like all the like. the very nice Christmas wrapping. We've got the Usbs.

We've got a C for you sea fishing. Oh thank you very much. Um, yeah, that'll have to be for next year. We do enjoy these.

It's another Christmas light. We've got a lot of these. We actually got a big collection of these we bring out every year. Um, Merry Christmas from uh, Elimo Engineering Limited.

Elimo.io Thank you very much. I don't know what micro that is. We've got a little micro down there. the Usb.
Not sure why you went with the vertical instead of the, uh, right angle, but uh. okay. Anyway, I'm sure that, um, have we got multi colors so we've only got the single color jobby there. Anyway, very nice gold trim around the outside of that.

I love how they look like, um, little stars that that is. a nice layout so let's plug it in. Oh there we go. There we go.

Yep, Mult multi-color jobbie. Hang on. Gotta turn the lights off. Well, I won't turn them off, but it does look.

I mean this is the this is the light in the lab that I actually normally use while I'm normally walking working. There's not many lights on, but uh. nice little flickering. Oh look, that's very nice.

Nice flickering action. Wow, that's I That's probably the best. Ah, nice look at this. This is probably the best action I've seen.

Wow, that's very pretty. I like that. Thumbs up. Well done that will have a pride of place on the Eevblog Christmas tree next year.

Unfortunately, not this year. Lmo Engineering Hi Dave Fanny a video since the very beginning and every time I see your bail bags think of myself I should send something. Thank you very much. So I thought I'd take this opportunity to send you one of the trees I designed.

maybe Seed and Huxley will get a kick out of. they will. Indeed, I think it will be their favorite. I pretty much guarantee it will be.

His little engineering company recently turned three years old. Congratulations Didn't fail because like like if you can survive the first three years, you're probably doing all right. It will. uh, also work with power banks.

It will turn themselves after a short time. Yeah, I'm powering it from power bank at the moment. This one doesn't. Uh.

but I do actually have other power banks that yeah, they need like a minimum current and sometimes it's actually quite significant. And if it's under that like pairing small projects like this because this wouldn't take much, this would be even though it's got quite a few leads on there. This is, uh, you know, Pwm didn't sniff of an oily rag kind of stuff. So anyway, use it.

There you go: 80, 20, 167 Uh. Leads are addressable type Arduino compatible. Okay, they're one of those you know whiz-bang things that you can get from the Art of Fruities and whatnot. Um, and fine details and schematics.

I'll link it in down below. thank you very much. Even though it is, I missed Christmas. Sorry Simon.

Thanks mate. All right we have one from China. We have Spoiler Alert a multimeter. Well, it does have the model number there, but I've got no idea what that means.

so let's check it out. Hope it's not a Bloody Nother Kaiwee Kay Wheats, Kai Wheats thing. They keep hassling me and I keep sending me stuff uninvited and I don't know having too many sucks of the mailbag. So let's have a squares.
What do we got? Yeah, looks like it might be them and a bloody well is again. Again, No, we've done this. Haven't we done? We've done this bloody thing, haven't we? It's it's the same, isn't it? I'm just no. Oh god no no.

Okay, I don't think we've done that exact one. It's yet another. um. variant.

Oh god, isn't one of the color? Is it one of the color screen things? I should give them a fair go, but they've had too many sucks at a seven. It's just. I don't know how many bloody variations of these meters can they make. It's Qc passed.

It's got to be good. Um, oh, it takes four four. Oh, I was wondering why they gave me four. I thought they gave me two packs, but no four.

Triple A's leave that off for a minute. That was non-captive and yet color like. Why? Why? Where is the value? Where is the value in that? And like this looks almost identical to the other one in form factor? Okay, 22 degrees Celsius? Well no that's wrong, but it's been in the box. It's actually 25 in here at the moment.

Um, yet. no. it's got the same silly auto thing as before and it's like, no, I don't see the point, especially like I think didn't the other one have these sockets on the bottom and at least that was kind of like useful be like in a pocket sort of form factor even though it's not real. You know this is not a pocket meter so it comes out like a normal meter.

but it's like got a phone form factor and it's got a Led light in the back and um, yeah, there we go, we can. Oh wow, wow, look at that. There we go. Isn't that wonderful? Now I'm sure it operates like the same as previous ones I've done.

I'm I'm not going to waste my time. I'll do a quick tear down. Anyway, it's got self tappers here. no fuse access.

It is. uh, it claims to be 600 volt Cap Three. Yeah, nah. um so let's take this apart.

Does have a metal threaded insert there for the battery compartment, but oh, there we go. We do actually have a Hrc fuse and yeah, this is like it's similar to the other ones. Um, we've seen. Yeah, it's just got the the press jacks just sitting in the plastic like that.

But you know these things are like 20 bucks delivered or something. I don't know. 20 or 30 bucks delivered. And we've got one uh, Ptc on the input.

That's it. There's no mobs, uh, whatsoever. Um, and yeah, I think we've seen this before. We've got a blob, we've got a display drive so it's a multimeter chipset.

Um, then we've got an Lcd uh driver. and then we've got a Um relay in there because this does like auto um switching because this doesn't have a manual range switch. So you know, ultimately, almost certainly like end up with or that's why you end up with a relay in there. Is that one? the latching? uh, Jobbies or whatever.

But anyway, there's our current shunt resistor. I'm not fast. Technically, that's a Hrc fuse. Well, it's a ceramic fuse, you know.
Anyway, looks like we might have one pair of protection resistors there, and that's it for the uh, clamping. But yeah, beyond that I'd like. I don't know why do these exist. so let me know in the comments down below if this oh oh oh look oh look.

I was wondering why the script look I can press on the screen. Look at this. I've just like completely ruined. Oh well, not I haven't physically.

look look what I can do to the screen. This is hilarious. Look at this. I'm pressing on all those poor liquid crystals.

Oh my goodness. got. nah, that's terrible. Muriel.

Oh my goodness. It's kind of funky though. I can kind of produce some funky patterns with that. But oh my goodness.

No, no, no, no, no. Anyway, leave it in the comments below if you think that you know if you find these form factors um, and sort of like, uh, usability and like the screen. If you think these things are great, um, then yeah. leave it in the comments down below.

But I I don't know what sort of niche these are fulfilling. I like, it's just wankery. I don't get it. Thanks to Charles Holly from Dunmo in the Uk.

Uh, to hide all my viewers in Dunmer, I wonder how many I've got anyway. Um, not Austria please? Australia? obviously. Uh, they've had a redirect on this and they've like whacked another sticker over the top. so there was something under there.

Thank you very much. All I know is that spoiler alert. It's electricity equipment. Um, that could mean anything.

Oh really. I don't like doing this behind the camera. I can't believe I did that for so many years. How many years did I do mailbag behind the camera? Anyway, it's padded for our protection.

Looks like we've got we've got two separate items. Or is that no, that's just filler. We've got a doodad and more. filler.

Well packed both ends. so do we have something with um, you know a thingy at either end? Let's have a squiz and aha, this looks yes, this looks electrical equipmenty doesn't it? It's a radio Teleswitch Yorkshire Electricity made by Hortsman Controls Limited Uk. Um, I wonder if this is um, a a radio teleswitch, right? Okay, so is it an Rf thing? My first thought was that oh, it's like a Uh line receiver for the off-peak electricity thing which we have here. but it's a radio based tiller switch.

Okay, there's our big interface like that and it's not that old. Um, is that 2002? So okay, uh, it looks like yep, just like the electricity meters so you don't diddle with it. Um, it looks like you can put is that for um, like one of the like the tags on there, the uh, secure tag. Things best that we read the note.

Uh, greetings from the Uk A two minute tear down. These were rolling up in 1980s in order to do large scale on demand grid tariff control. Yeah, I thought it was some sort of Tara thing think cheap electricity at night and expensive today. Yeah, we we call that off peak here and uh, they put like a one or two kilohertz tone on the uh mains and which can screw up a lot of equipment by the way that's sensitive to any noise on the mains.
You can actually pick that up, you can. I know that some mains powered uh clocks will run. you know, occasionally run haywire and fast if they're not designed, if they're poorly designed and stuff like that. Anyway, yeah, we we do that.

We still have that. We still have, um, some people still have um, uh, off-peak uh things and they have you have an analog receiver in there and um, this signal that they send out at night. You know, at midnight or something. It uh, triggers it and then you know you get your cheap power and it turns on your electric, um, hot water so that you know they do grid, uh, management as you say.

So it's got an 80 amp contactor to control heating loads. Yeah, exactly the same thing. Uh, phase modulated signals on Bbv Bbc Radio 4 long wave carrier at 198 kilohertz. Wow.

there you go. There are a few specs and blogs out there on the system. The whole system is said to be quite resilient. The technology is interesting.

I think it came before cellular networks, the internet, and all those year things. Uh, when this left the Uk, it did work. but as you won't get a long wave, Radio 4 over there probably won't work anymore. We could actually generate it, but yeah, you'd have to know the protocol and you have to modulate it.

Is it just like amplitude modulated jobby or something like that? I don't know. have to look into it. Yeah, there's no back channel for the teleswitch. Yeah, that's the same with our system.

It's purely one way. If it works, it works. If it doesn't, well, your hot water stays. doesn't get hot.

The only way to monitor the system is to watch the electricity demand grid live from a grid point of view. Yeah, In like an overall thing, they can't tell that an individual house has turned on their hot water system. So we've got a linear power supply, joby, and Rf antennas. Normal Am stuff except for the uh, microprocessor.

Okay, so it's amplitude. It is amplitude modulated. Um, to decode the phase modulator and it's got a micro. Oh fancy panty.

Oh, there's a New Zealand youtuber, Um, who specializes in electricity meters. Um, there you go. check it out. I have to link that one in down below.

Anyway, up there standardizing Bs7647 if you're interested. Awesome! Anyway, there's an indicator down there so I guess that indicates that that flicks. that's in like an actuator that comes down and it's red. Um so like that visibly like.

So when you go and check your meter box you can see. I guess if your loads on but you're loaded be your hot water system electric shock risk. So oh no. Okay yeah I'm manually doing that but I don't think he's supposed to do that manually.
I would have presumed that that was just an on off indicator thing and you'll notice down in there it's got a uh, looks like an infrared comms system so they can come around and diddle with it and update the uh, firmware. presumably. All right, I think I've got everything. Let's lift it off and ta-da Well yes, as you'd expect and that is your antenna coil because it's 198, uh, kilohertz or whatever.

So yep, you need a decent uh rod antenna like that if you ferrite in there good old am um antenna which you'd get for your uh, old-fashioned am radio. And it looks like we got shield in as well. But I can imagine like there being a reception problem. I mean yes it is.

I am, but I I don't know. Hands up. Um, if you're in the old dart or if you've got any of these in your own other countries and you've had uh, reception, uh problems. I don't think it could be in the dark dungeon or something and um, yeah, it just doesn't work.

But anyway, um, is that a little relay can or something? Yeah, like point-to-point wiring stuff like that. There's your big contactor. there. It is there.

Oh yeah, they are. Yep, this is not just a manual thing. this actually has got a big solenoid in there. Which then there's your gigantic contactor.

and there's your two big contacts down in there. and it just bridges that. They don't have one. They got two.

That's interesting. Hmm, it's kind of like it doesn't seem really solid. like the there's a pretty wimpy little spring in there that's like holding that. I don't know.

Oh, that's a bit dicky. Well, yeah, there it is. It is. uh, pretty basic.

Just a linear um. supplier with transformer. Is that like a just a single? Yeah, that's just a single diode rectifier. Got a big mains filter cap.

Oh, there you go. Oh Dubliah. Oh classy. Um.

3300 mic joby, and uh, a couple of smaller ones there. What brand are they? We got a Ruby con over there, so yeah, I don't think they're going to be getting the uh, Shenzhen market specials in these things. Oh there it is. Old school illness.

So Rubicon, Elna, and Dublia. that's great. Yeah. Fantastic.

Um, oh no tents. Oh, I take tantalums. Got the heebie-jeebies It's an 87c 800 F and I'm having trouble finding data on that. Um, I even got a reference to Toshiba so I'll try and pull up a data sheet.

but geez, yeah. um, not really a uh, mainstream micro there. And yeah, they just got the crystal. and yeah, well, there's not much else.

There's the uh, analog receiver. over here. there's the Am receiver. What's that part? Um, that'll just you know, be an Am receiver chip that'll just give you a i presume.

would it just give you a data stream output from that from the amplitude modulation? uh, perhaps. Which then the micro uh, decodes. and Bob's your uncle. So yeah, like there's there's nothing doing there at all really.
And there's nothing on the arse end of that either. But uh yeah, I think that is a relay driver down there. So yeah, they might have some discrete down in there driving it. Perhaps.

Yep. Can I crack this bad boy off? That's just a shield, right? Yep. Yep. They've just shielded that.

There you go. Just got some magnetic shielding. Does that prevent people doing it themselves with their magnet? Perhaps. I think that's what it might be.

I think that uh, yeah. I think that's a new metal thing to prevent. Um, because that would be what on the other? No, that's on the top. Yeah, that's on the top side.

there isn't it. You could certainly put a magnet over that and potentially do the contactors and then activate the solenoid so you can get your hot water. Um, during the day and they don't want that. I mean, that's the whole purpose of this thing.

So there you go. What brand is that? Is that? just some Chinese brand? Not sure. So yeah, there you go. Uh, that's interesting.

An Am receiver? It's just got an Am receiver chip. It's just got a little, uh, fly. I presume the F on the M F on the end means that's a flash micro. And of course it would be because they've got a little Ir interface here that you can reprogram it just in case you know they want to change something.

They have to send someone around to every home and they would have to reprogram them all. Let us know in the comments if that ever happened. So there you go. Fascinating! Now, if you've got any details on the um, like the coding system for the amplitude modulation thing, then please leave it in the comments down below.

Thanks for sending that one in! Fascinating! So thanks to everyone who sent in something to the mailbag, I do actually have more, but I decided to like keep this relatively short compared to all my mailbags. Didn't want to open like seven or eight items. Let us know down below, if you think that's a good thing, catch you next time.

Avatar photo

By YTB

20 thoughts on “Eevblog1457 – old school mailbag”
  1. Avataaar/Circle Created with python_avatars Martin D A says:

    Imagine seeing those FET specs when we were spotty youts! 1.9mOhm and 180A in a package 5mm square. Still mind boggling to me. These kids today don't know how good they have it. I used to have to lick the road clean…etc…

  2. Avataaar/Circle Created with python_avatars Mad's Tech says:

    Usually it’s over current from a burst or a short. the manufactures specs are often plucked out of the air most of the time and frankly can be nonsense. Gear is much better now but while they can say 40A per channel things can be vastly different. While the FET’s can be properly rated the boards can actually burn due to the current though the tracks or caps let go with spikes and burn though the board and short and then it’s fire. Things are better today than ever but a Lipo will easily deliver 200A.

  3. Avataaar/Circle Created with python_avatars Richard Garnish says:

    Not only is 198kHz good at penetrating buildings etc., it also comes from a 500kW transmitter right in the middle of the country. We used to get perfect BBC R4 reception on LW, in the basement, in Brussels when we were living there (which was handy when they'd broadcast the cricket on the LW station while the FM frequencies carried the usual dull Radio 4 schedule.)

  4. Avataaar/Circle Created with python_avatars Dr Dr says:

    I love the classic mailbag, hell it's why I became a Patron years ago. I was a bit saddened by the halfsies run time to be honest. 🙁

  5. Avataaar/Circle Created with python_avatars IanScottJohnston says:

    Had a few ESCs go bad in my RC days. Cheap Chinese ones mind you, and they usually die spectacularly given the big LIPO batteries feeding them. What makes it worse is the heatshrink that the ESCs are wrapped in help contain all that explosive energy within and thus the whole lot ends up burnt to a crisp.

  6. Avataaar/Circle Created with python_avatars Joey Strong says:

    I wish kaiweets would just go ahead and try their hand at a decently protected meter with that screen. Something in the ut61e+ range. Not professional but good little workshop ones with decent resolution. I've made it my quest to get the eevblog bm786 after my smd removal stuff and I get a decent oscilloscope not made in China.

  7. Avataaar/Circle Created with python_avatars Leo Pryside says:

    I've destroyed many escs over the years and one common reason why they die is usually due to voltage spikes. Especially these cheap quadcopter escs only use a simple ST32F1 microcontroller to control the mosfets and they make a lot of "mistakes" dont switch fast enough or miscalculate the rotor position, this combined with the high rpm and high back-emf causes voltage spikes. If the input capacitors are not big enough and there is no overvoltage protection like a tvs diode on the input, these voltage spikes are too high for the mosfets to handle which exceeds their rated Drain-Source Voltage. Thats really often why they die, bigger Caps with lower ESR combined with a TVS can prevent this.

  8. Avataaar/Circle Created with python_avatars Mark Robson says:

    Maybe the drone ESC was the type which uses N-Channel mosfet on the low and high side, using bootstrap driver circuits? That's certainly common. Still very burnt.

  9. Avataaar/Circle Created with python_avatars Michael Moore says:

    The value of the Kaiweets quadrupled when you put the batteries in.

  10. Avataaar/Circle Created with python_avatars DingleDodger says:

    kaiweets trying to get that free QA/QC and publicity out of ya.

  11. Avataaar/Circle Created with python_avatars Vince I says:

    I won't lie, I skipped the multimeter segment. Don't judge me 🙂

  12. Avataaar/Circle Created with python_avatars MultiShizmo says:

    ESCs usually use a bootstrap circuit for high side switching of n-channel mosfets, they typically don't use p-channel due to the higher Rds.

  13. Avataaar/Circle Created with python_avatars Geir Endre Jenssen says:

    "Everyones favorite MAILBAG", really?
    To bad it's months between them then.
    "Nah, couldn't be bothered" I guess.

  14. Avataaar/Circle Created with python_avatars Hola! Airzone says:

    I make my own esc's. Never blown a motor, but am all too familiar with the smell of esc smoke 🙂 They are pretty good though and the motors do take a hell of a beating. There's rarely any overcurrent protection, so if anything does go wrong, it's all over. The top mosfets will be the exact same as the bottom. The 3 top side chips are the gate drivers, and it was probably just heat through the board that desoldered them. If I had to guess, one of the fets failing closed. The ESC can't detect that and would happily turn on the opposite side of the half bridge. And then the internal power traces all blew apart – which is why the pcb is splintered near the battery connector. It's pretty rare since the fets normally fail closed. ANother thing that can happen is the mosfets are running too hot, and they desolder themselves in operation and pivot and cause all sorts of chaos. Not sure how the heatsink would impact that.. But I did have one fet rotate 90 degrees on an early board of mine.

  15. Avataaar/Circle Created with python_avatars Janus Kobain says:

    The only fun you had was because of squeezing the display.
    How miserable the device should be then.

  16. Avataaar/Circle Created with python_avatars henrik ostrov says:

    The first code for the led tree is called demoreer100 in the fastled library in arduino edi.

  17. Avataaar/Circle Created with python_avatars Fish's Drone videos says:

    Regarding quad ESC's they have been getting better. I've built about 8 quads lately, only 1 head DOA ESC's and the others are trucking. Even after crashing into wet grass enough to dead short…something. It came back after drying out.

  18. Avataaar/Circle Created with python_avatars mikeselectricstuff says:

    Re. the teleswitch, 198khz should penetrate pretty much anywhere, but nowadays I suspect interference from myriad SMPSUs, LED lights etc. could be a problem. I wonder how secure these are from locally overriding the signal – probably doable mostly in software on a Raspi or similar.

  19. Avataaar/Circle Created with python_avatars Al Armandi says:

    it's a good thing! (the format!) ;). you just decode and reveal the mystery behind one of those old and persistent online ads for me! they use to show the closeup picture of around magnet in someone's hands with a large title, something like "your power company doesn't want you to know this simple trick…" now I know what :))

  20. Avataaar/Circle Created with python_avatars SeanBZA says:

    Going to guess the tiny little capacitor that was supposed to generate the top N channel drive voltage shorted out, likely the little ceramic in the top row that turned to powder. The small desoldered chips likely are the drivers, and they commoned all the top drive connections to save on 2 capacitors, so when it shorted out all the top N channel parts were running linear, and went flambe, and then the top shorted out on one or more phases, and DC cooked the motor, just about the same time the ESC was also doing full flame generation. Stopped when the traces melted through and acted as a fuse.

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