Hi welcome to Tear Down Tuesday Sorry if I'm making some people motion sick, but we've got something a bit unusual today. We have a 3D rocker. What the hell is a 3D rocker? Well, as its name implies, it's a threedimensional rocking platform. It rocks something around and around and around in three dimensions.

it's from Stewart Scientific. It's the 3D rocking platform st9 and um I scored this for next to NX and well I don't know. It just has to be useful for something. I don't know.

it's just kind of cool. and here it is shaking my new uh A10 if I can read it PPS 3205 T 3s power supply. Um, it's rated up to 10 kilos this one I believe. And this power supply is not too far off the mark and as you can see, it's just designed to rock these things at a very slow or Rock things at a very slow rate.

I Think this one goes from about five revolutions per minute up to 70 revolutions per minute. So at 60 of course, it'll rotate at once per second and it's a spit of scientific um. laboratory, uh apparatus that is designed to shake. Uh, you know.

flasks of chemicals or beakers of chemicals. stir them up in a three-dimensional motion and you can get all different types of these things. You can get ones that just shake them in a linear like a linear shaker like that that just shake back and forth or in One Direction only left, right, back forth. And this one just rocks like that.

so it's good for stirring. Uh, you know liquids and things like that? If you're you know if you're into chemistry or whatever, and you're you know you need to mix chemicals in a certain predictable way. Uh, or samples specimens. Whatever.

That's what these things are designed for. So I thought well, you know it's practically free and well I don't know. It's got to be useful for something. Surely, if you got any good ideas, let me know.

So this is not going to be an exciting, uh, tear down from a technical point of view, folks, Because what? What's inside this thing is a Mains onoff switch. There's a motor onoff switch and there's a variable speed controller. and really, um, inside? I Don't expect anything more than just a basic, um, you know, motor speed controller. Probably very similar to ones used in, uh, handheld drills or something like that.

similar, sort of, you know, motor controller. uh, system. one little board in there to drive that driven directly from the mains and well, that's it. But I Thought: maybe we can make it go a little bit faster.

Maybe we can make it go up to 11 on the dial? What do you think? and no, there's not going to be any fancy. Mechanicals Inside I Don't think it's just a, uh, it's just a regular motor which just then, um, turns like an angled offset, um, pivot joint, uh kind of thing. I Don't know I Don't know. My mechanical engineering is probably a term for that sort of uh, you know, uh, pivot type joint which then, uh, rocks the platform on top so it's just a it's a basic drill that just turns around so well you know it shouldn't be.

um, hard at all to uh, reverse engineer the circuit in this and uh, hack the thing I'm presuming anyway and hide to all my UK viewers made in the United Kingdom in the Old Dart and no, there's absolutely nothing interesting on the back, just an I Mains input connector and uh, and as you can see, it comes from Glaxo or what I think they're now called Gxo Klein Smith They're a pharmaceutical company here in Australia so you know, eh, mixing chemicals? Who knows what they're doing with this thing and it does have this arm here on the side. but uh, I don't think it, you know it. it just maybe it doesn't Actually, you know, exert any force on there. So I think it's just there to uh, stabilize it or something like that.

Perhaps that's I I think that's its only role I don't think it's uh, you know, really, there's a huge amount of mechanical stress on that I see like there's a compliant rubber in there and and really, it just it sort of bounces up and down. So I think it may be just uh I don't know, taking out some sort of vibrational mode or something like that. perhaps? nothing exciting on the bottom? Of course we've just got some screws here that looks like it holds this base on and I think it's just going to pull off like that. So I'll probably expect the motor to be mounted on the top, fixed to the top case and then you know the controller board just mounted on the bottom here Somewhere like that and that's probably all she wrote.

So let's take it apart. Here we go. Let's take this thing. Yep.

I can see inside? Yeah, it's exactly what I thought hang on, there's some cable tires holding it in place I may have to flip it around and that's all we got inside. A little tiny controller board here as I expected. and uh, there's our motor with a little Optical encoder on it. We'll have a look at that in a bit more detail.

There's the feedback sensor which goes back to the controller. keep it at a uh specific uh, rotational, uh, speed and um, well, that's it. Bobs Your uncle and here we have a basic brushless uh AC motor. You can tell it's brushless because of the external coil around here.

There is no uh brushes like you would find um, brushes and contacts like you would find in an electric uh drill for example. That's why in drills you because they have the brush contacts on there connecting the coil inside. That's how they generate. You know you see Sparks coming out of it from those uh brushes and uh, they've got a very limited uh lifespan.

These things are, um, incredibly reliable because there's no brushes to wear out or anything like that. They just use the optical uh encoding here to uh as a Tacko to set the uh speed driving this thing and that's it. There's a permanent magnet inside the rotor down inside there, and uh, that's all there is to it. Very simple.

and there's our photo transistor and Led combination in there, and of course our wheel with the black marks embedded on it. so that as it, uh, as it spins around, of course it interrupts the Um LED and the photo transistor in there. and uh, it can get a pulse out of that which feeds back and controls the speed very well. fairly.

Uh, precisely on these particular types of Motors Um, very simple, very reliable, and it looks like we have a reduction mechanism. uh, down in here cuz there's the shaft which goes through into there and uh, that just uh turns that you can see as I turn the wheel Here, you can see that just rotating very, very slowly if I put some speed on that. There we go, you can see it rotating so there's a fair Fairly big uh reduction there. but um I don't know how fast we can.

uh, get this motor up to I Guess we'll find out. And here's our control board. Uh, very simple one. TDA 2086a I Assume that's a motor controller, don't know that one off the top my head.

We'll have a look at the data sheet for that thing. but um yeah, powered directly from the mains. Here's the mains input here. We' got our big Uh dropper resistor there.

Yes, the power is turned off because this folks is all. this board is at Uh Main's potential so you don't want to go probing around in this thing. um, with your scope. I've done a whole video on that and how you can blow the ass out of your scope.

You've got to use a proper high voltage uh differential probe or a portable scope which I uh tore down last week. and if you have a look at the Uh Earth terminal here coming from the IC Mains input, of course it goes to the Uh metal bottom of the metal case and also goes up to the Uh top here on the Um metal or the metal shazzy up here for the motor. but it doesn't of course go to our board over here. Now of course the in the Uh men's system, the multiple Earth neutral system uh, back at your house or or your Uh board or whatever distribution board or panel or whatever it is.

Of course your Uh Earth down here is connected to your neutral and your neutral will be connected all the way and that'll be the negative. the neutral input on your IC Mains connector will of course be the ground in quote marks or the negative uh point on your board over here. So in theory you you can if your wiring system is all correct and hooked up properly. In theory you could connect your ground lead of your scope probe over to the negative point of the circuit, but in practice you do not do that.

You need a proper isolated high voltage differential probe, so if you hook your scope probe up to that, of course you would have this huge uh Earth Loop between your oscilloscope going all the way back to this thing and well, it's not a nice situation and if your PowerPoint or wiring is incorrectly wide, um, it's can be incredibly dangerous. Take care when you're probing and playing around with these things, folks. keep one hand behind your back and check this out. We have a little trim pot down in there so I wonder if that sets the uh maximum speed or not? I don't know.

It's uh, worth a tweak. Well let's take a look at this thing spinning. I've uh, powered it up and let's take it right down to sort of. That's like minimum and it's just got enough Tor to just switch over there and I take it up to the first marker which is uh I don't know.

It's uh, one revolution per uh minute. So that's the speed. One revolution per minute. 10 and then woohoo full on up to 70 revolutions per minute.

But of course this is faster because we have a reduction gear um inside the thing of course as you can see, there really isn't uh much else on there. There's a triac of course for the motor control and uh, a huge power dropper resistor to power the circuit. and we've got our um Mains rated uh cap of course. but and really, there's not much uh to these things.

We're going to have our triac of course, which uh is our power device which uh, controls the uh motor, uh, chops the voltage up going into the motor and uh, we've got a big Power resistor over here. some uh, little ceramic standoffs down there. that's of course. uh, directly.

uh, Main's powered and really, um, not much else. Um, the circuit's probably uh, straight out of the app note and I've reverse engineered this board and I got a horrible looking circuit like this which ends up if I redraw it looking quite smart and funky like this that you can see in this Dave CAD drawing. Now as I said before, it'll probably be very, very similar to the Uh app. Note Well, the actual data sheet the TDA 2086 A here it is and uh, it's I don't know if it's still a current part was a bit difficult to, uh, find the Um data sheet for it, but TDA look here is the uh typical Universal motor application as they call it for the TDA 2086a.

And yes, if you actually put them side by side, it is absolutely identical to what I reverse engineered here. No surprises whatsoever. Now there's a ton of detail on how this uh thing works. It's you know, it's fairly complicated and the data sheet has, um, some brilliant explanations, theory of operation, and all that sort of stuff.

So if you're ENT all your uh, motor control and things like that, highly recommend you download the data sheet and take a good look at it. But the Uh circuit is, uh, nothing special at all. Here's our motor here. Uh, the triac is a T410 600.

um, nothing special. direct Gate Drive from the chip of course. and uh, that controls the speed. and we've got a taco here, which is our um photo transistor.

Here's our Uh LED here. Here's our Uh 2 W power dropper power resistor here which goes through in series with the photo transistor LED there and um, through another diet and that is the V+ for the Chip And If you do the math uh, power equal I 2 R on this thing, then for a 75k 2 wat resistor in series with that Led current, you'll know that that can only be drawing. uh well, there can only be 5 milliamps maximum current through that to dissipate 2 wat power in that uh dropper resistor there. So likely it's running at.

you know, half that or uh, 2 and 1 half milliamps or something like that. Anyway, um, it's got an internal regulator so that generates the power for the chip. There's also a Minus 5vt internal uh generator as well. Actually, when I'm talking about minus5 Vols Here, this one here isn't actually V+ it's actually V minus and that's -5 Vols there.

So the whole thing's operating on negative potential, so this cap down here will actually be negative like that. and this, uh, what you think is ground down here is actually uh, positive in respect to the minus5 Vol Rail there. That's why if you have a look at the Uh board here, this capacitor down here is actually it looks like it's back to front like that. But because that's actually -5 Vols there instead of + 15 and you're probably asking, well, why do they put this uh diode here in series with the supply here? Well, if you just of course you could if you didn't use that, uh Taco at all, Of course that would be wired straight through and you just have the chip and the circuit uh, drawing power from there.

But of course this draws its own power. And um, as the calculations before, even a couple of milliamps can have very significant power. You know, a watt or two couple of Watts dissipated in this power resistor here. So if you had that shorted directly through power in your circuit, you'd still need that one or two wat big resistor there.

And if you had the separate lead powered from the same uh powered from the mains rail as well, you'd need an additional Uh Power resistor in there just to power the you know, two or 3 or 5 milliamps going through that Led. So this is just a way to cheat because you got such a high Mains voltage here, you can just cheat and put the LED in series. so you uh utilize the current flowing through there and you only need one dropper of power resistor. Neat circuit optimization.

and then we've got a voltage syn uh signal coming from here which is just your Main's input and your current sink coming from across your triac there. So and the rest of these down here all have to do with how the block diagram this thing works and how this all works can get relatively complicated. Go into the details. we got difference limits.

we've got frequency to current converters and all sorts of weird and wonderful stuff. and you'll find one difference in the schematic here in that the triac. There's no uh, load current monitor resistor like there is down in here because uh, that this uh pin five here is actually got a dual pin functionality and it's not actually utilizing any uh load current sensor in in this particular application doesn't really need it. So unfortunately our Um series pot down in there isn't really going to do much.

I Think it just. uh. it mainly adjusts the uh, lower speed uh threshold of the thing and that's that's probably it. It just stops completely so and it takes longer to start up so that's no good for increasing our speed.

If anything, it just lowers it. And for some bizarre reason, the circuit actually does have three parallel resistors in here. I Mean this is a 50k pot. I Mean there's no current flowing through this thing at all, but they do actually have three parallel resistors wired into the circuit.

I Have no idea why. trimming? All right? What I'm going to do now is have a quick probe of the Um Gate Drive signal on the triac there. So I've got my uh fluke scope meter here. No, I'm not going to use my regular scope my regular grounded scope.

of course. this one is a floaty in scope. so I can do that as long as I don't touch the probes down there. I'm all fine.

Sorry for the crapiness of the Uh signal here, but you can see the positive and negative transitions. uh DC coupled. Um here on uh where 5 milliseconds? uh per division? uh 500? MTS uh per division vertical there so you know we're just over. you know, 650? MTS or thereabouts? Um, positive and negative? Peaks and I've got that at about 10 RPM or thereabouts.

Uh, so let's take that up to 70 and we can see it sort of jump over the place as it's trying to hunt to, uh, keep this thing at a stable speed. This scope is really slow folks. it's uh, absolutely terrible. so we can't see all the F We There we go.

can't see the fine detailing there. and if I physically stop it with my hand, hang on. There we go. Oh, it's it's stopped.

It's barely going at all. and if I let it go again, it slowly recovers, back hunts, and it generates the required uh trigger signal to keep this thing at a constant speed. Okay, so I've got 30 RPM on there with no load at all. and if I put my hand, what I'm going to do is I'm just going to put my hand on here like this and just sort of apply a bit of force like that just to hold it sort of.

You know, just to give it a bit of extra force. and let's see what happens. there we go. You can see it expand out the uh on time so you can see that pulse really expand out and where it the time when it's widest there, that is when it's actually trying to really, uh, go against my hand.

So because this thing's moving up and down, it's now gets my hand so it goes really wide. Like like that, it's really trying to keep it going and on the other part of the cycle then I'm not applying much pressure. now. if I try and apply a constant amount of pressure I can maybe try and keep it over there but a it's pretty hard but unfortunately folks tear down.

Tuesday has come to an end I have run out of time today I have to get home and of course people will complain if I don't edit and upload the video today. So which is uh Tuesday there it is. Check it out, it really is Tuesday it's uh, 6:00 p.m. I got to head home and uh oh, lots of things happening today.

Big uh server upgrade uh just took place actually. So my um Eev blog and uh Forum uh website. they're all run on a dedicated uh server and that just got uh upgraded and that's done by uh host Gator who's my web host provider and they upgraded me to new hardware you know, standardized Hardware at some uh Xenon uh Zenon processor. however you pronounce it something like that dedicated server.

it's all running. seems to have happened really smooth, but if there's any issues at all, uh, please let me know that'll uh, that'll happen in the next couple of hours. Just change the IP addresses and all that magic geeky stuff penguin stuff. So anyway, um, hope that goes all smooth.

Lots of stuff happening at the moment. I'm was, um, hoping to uh uh, play around with this, uh, more measure some more stuff, hack it and things like that, but unfortunately, um I might have to leave that for a part two, you know what they saying Show Business Always leave them wanting more. Catch you next time.