This should be interesting. It's a remote control fan control module from China and this was described as 300 W Air Conditioning Fan Circuit Board Universal Control Module and remote control comes as the main circuit board. Well, I'll show you what it comes up. Cost: 959 Shipped from China Could be useful for repairing uh, small air conditioners, not ones of compressors, just the standard ones that use water as a cooling agent.

So in inside the box is the console that goes in the top of the unit with clicky buttons and LEDs and the infrared receiver. We've got the main control circuit board I say the main control circuit board I'd call this more the power circuit board but the look of it. uh that has the Trxs that switch the power and the power supply and then we got a remote control with the use little tab. um for controlling it with a little are we going to be able to see the LED Oh a little little glimp of the LED I think yes, you can barely see it right? Tell you what, we'll open this unit up and I'll take some pictures.

let Zoom down and we'll see what the circuitry is like and how this thing is used. I Kind of know how it's used. It's basically it's a five triacs. Three of them.

the big ones are for the fan speed control and uh, one of them is for The Swinging The Fan Batters and forwards or you could use it for an iron if you wanted and the other one is for a pump I think for pumping cold water over one of the Uh filter materials to actually give a cooling effect. So there is the magic chip with no number on it. There's a surprise and we have the clicky buttons. We got the infrared receiver and we've got the LEDs right.

Tell you what? I'm going to take some pictures of these and then we'll reverse engineer it one moment. Please is reverse engineering is complete. Let's explore. So on the box underneath a big sticky label they'd put over it to show the stock number was basically a guide to how to wire it, but it's irrelevant.

Once I've removed the label, it showed a completely different circuit board with the chip on board and the remote control infrared receiver on board. Um, and only four outputs whereas this one has five. so that's completely irrelevant. But the instructions are there kind of in Chinese if you need them, but my instructions will be much better.

Let's Zoom down in this. So this is the main power card. It has a capacitor that is 1 microfarad 400 volt and it creates a 5vt supply courtesy of some various resistors, smoothing capacitor, decoupling capacitors and diods in the back, and then a 5.1 volt zener that Supply then goes up up this connector to the remote module and it then controls five triacs. three for the motor, the main fan motor low, medium high, and uh, a couple of small ones for the swing, the ocut that moves the thing backwards and forwards, or the grill backwards and forwards or rotates the grill and uh, cold which seems to well I'm guessing it runs the pump for the uh, evaporative cooling effect.

There's also a little beeper. now. this little link here is either bridged out if it's not used or I think you can put a float switch there to control the pump and all it does is it breaks the feed to the track on the back of this Cirer board not a lot on the back of the Ciruit board on the back. we've got some diodes as part of the power supply with the sticky stuff.

The circuit board was pressed up against the controller. let me just bring the controller in here and it had peeled some of the uh adhesive sticky pad here for just jamming onto your case of whatever you're actually fixing. uh, so that was quite hard to move so I just took the pictures with it on uh but we've got the discharge resistor for that capacitor. Quite a low value relatively speaking 220k.

it's going to be pushed, it's going to be dissipating a bit. uh. And then we've got a couple of diodes which I'll show you in the schematic couple of resistors to limit in Rush current and uh filtering for the Uh power supply and then just a couple of like little uh surface mount decoupling capacitors. The only other things worthy of note in the back here are 330 ohm resistors for the gates of the tracks.

and there's also a beeper with a resistance of 15 ohms. and it's got a one microfi. Well, it says I haven't measured it CU it's in circuit I could measure that just by unplugging it. but anyway, it says basically one micard.

it's a small capacitor just to limit the current that can flow to the of uh the Beeper coil when it makes PP noises PP noises. Yes, good description. Let me zoom out a little bit for this. This is the remote control module and it has eight LEDs They're wired Multiplex so there's four LEDs and one Multiplex channel for and the other and the switches are also part of the multiplexing to save pins.

It has the infrared receiver which is just bridged across the uh same Supply as the microcontroller. couple of resistors for the LEDs cuz they're multiplexed and then one resistor here for the Uh feedback from the switches. All the switches are sort of common to that. um, not much else to see.

Let's go straight to the schematic and this schematic is pretty big. so I've divided it into three sections and we got live coming on Here it goes through a fuse and then it becomes the plus 5vt rail. So it's not just live feeding loads via these tracks. Uh, I've only drawn one in here just as a reference and I've just drawn the controller as a block.

but there. I'll show you the controller schematic. The neutral has the inrush limiting resistor. It's got a 1 microfi 400 volt capacitor with a 220k resistor across it.

Now, because one leg is referenced to the means of the DC Supply It can't use a bridge rectifier. So what it does is it simply uses one diode here to steer the current to the Uh capacitor here. Then there's a decovent capacitor, a resistor low value resistor, and then the clamping Xenor Diode 5.1 volt and then another decoupling capacitor. But um, because the capacitive dropper just can't operate in just halfwave, it needs this other diode that basically shunts uh, the other half of the main cycle via the capacitor via this diode.

so it can basically go into a state that it can actually pass current again. so it can basically charge and discharge in each half cycle. but it's only being used in half that. which is surprising because it's going to be using a fair amount of current.

when in a certain mode, I'll show you that mode. I've got lots of little Neons connected to that circuit board, so I'll show it working. Then the power basically goes out. This is what I'm going to show you next, the power going out to the control board.

Uh, which has that paper connected between the positive Rail and that capacitor to it? Um, so let's go to the control circuit board which is very minimalist and for Simplicity I've only drawn four LEDs and two buttons. see these colored lines these are the multiplexing lines they uh, turn on in sequence 1, 2, 3, 4, 5 uh I've only drawn two in because otherwise basically it was an extension. this it would have got very cluttered. so the supply comes up from the board and it's got another local decoupling capacitor, the infrared receiver going straight into the microcontroller, the microcontroller to light the bottom LEDs it pulls this resistor low which only Powers these LEDs that one's probably high or just floating and then it sequentially goes through these lines 1, 2, 3, 4, 5 and whichever LED is supposed to be lit, it will only go positive for that Led and therefore that say, for instance, uh, only Led1 was to be lit.

Only the pink line here would go positive in that sort of Step through sequence and that Led would light. Then once it's scan through the bottom LEDs it turns this resistor these LEDs off by taking the resistor high or just floating and then it pulls this resistor low and then it scans sh again and uh, whichever ones have to be lit only goes positive for that one. so that's how it could control all those LEDs off Just a few lines, but those scanning lines are also used for the switches and I'm guessing it's done separately I'm guessing that the Um both these Led resistors will be turned off so to speak. They'll be taken high or just left floating and then it steps through lines and then detects if a switch is pressed by the current flowing through the switch that's pressed to this 2.2k resistor and then back to the input.

And that's just to protect against things like multiple buttons being pressed, uh, while it's scanning and uh, causing a sort of like an issue. Um, that is it. The only other thing here is we've got one line going back down that ribbon cable for the Beeper and we've got uh, five lines going back for the Triax. Let's take a look at the Tria driving now.

I Looked up a previous video I did to show what these fan motors look like inside. For all the different settings, they have one base winding, one main winding, and then by switching the other windings in in series, it effectively increases the impedance of that winding that runs at lower speed. The capacitor is normally just basically dangling out the motor, but it has a connection internally to the neutral and uh, an auxiliary winding that gives the fan direction. It's sets the basically direction that the Fan's going to run.

it gives it gives it Direction That's the only way to describe it really. When you turn it on at the high setting, it's only this coil that is energized and then these ones are called energized via the capacitor. but this is the main one and it will run at high speed at medium. These two in series so a much High impedance Co that run at lower speed and so on.

The resistors are all 330 ohm and the swivel one is a much smaller track. These are BT 134s these are Mac 997a When it's wed to spivel the Louver or the whole unit, it turns this track on to switch that motoron and there's the one for the pump for the evaporative cooling that pumps the water over the filter. and there is its extra float switch and all it does is it breaks the signal to the Uh triac via that resistor to turn that Uh pump off. If the reservoir is run dry, that is it right? Tell you what, let's take a look at it running.

So here it is. I Have put I'll try and get these out The way that was me getting a spraying. a little nipping a nerve in the fingers there that wasn't a zap I Don't think it was a zap. it's not powered up yet and it does have a discharge resistor.

Oh, this is so frustrating Anyway, right? The buttons are in Chinese The translation didn't work too well. This is the time function and you've got the 1 Hour, 2 hour and 4 Hour they Li in a binary sequence. If you press it once it goes 1 hour, press it, and again it goes 2H hour. Press again one and two light to show it's 3 hour, press again, four.

So basically in the combinations it can go up to 7 hours. This button here is for the cooling and it toggles this Led on here, on and off and pump turns the triac on off for the pump. if the floats switches, uh, high enough. This button here is swivel and it lights that Led for the swiveling and then you've got the power on off.

You get infrared receiver and then you got the mode for the speed and it's low, medium and high. Unfortunately it was translated as low stroke and G Fang but it is low, medium and high. The remote control has uh Power it's got the speed uh control. It's got swing, enabl and cold enable for the pump, the timer for stepping throughout, and then it's got mode which beeps and does nothing.

Let's see if these Neons are even visible. So I'm going to make sure there's no loose metal strands on the bench and I'm going to bring this module in which is now live at Main's voltage. Note that this ribon cable, uh and all the circuitry in the remote here is live at Main's voltage. Now let's see if we can bring this in.

Wobble Wubble Wobble Power on you. You may notice a neon is lit that is the uh low setting on the fan. Then you. press this button and it sets.

goes to the next one. I'll just get my fingers out the way when I do that and then you press it again and it switches up to the high settings. so low, medium, and high. We have the timer setting and that steps through the LEDs on this one.

two, then one and two, then four, then four, and one and so on in a binary sequence up to 7 hours and then off again. We have the Cool the Cool lights this Led here and also toggles this output on here. The swivel does the same it uh lights the swivel Led up here and it also toggles on that and we can control it also via the remote control here. So I can toggle through the speeds by using the remote control.

I can cycle the pump on and off. I can cycle the swing on and off and then you can set the time as displayed on here. and then there's a Mode button which doesn't really do I'm not sure what the Mode button does. hold on.

going to turn it off and on again and then going to press Mode Nothing Don't know what the mode does, it's possibly just for another function. So the worst case scenario here. Why oh maybe Mode does something. Mode is chasing backwards and forwards between the settings.

So uh, Mode. Just basically, that's awful. H Mode just ramps the fan speed up and down right. We know what it does now.

Excellent. So the worst case scenario here is. uh, swivel and cool and one of the motor outputs well. it's going to be activating.

So that's driving three tracks at once. It's driving these. LEDs We could go one step F Further, we could get all the LEDs on here. That's the worst case scenario.

I think for uh, all the LEDs lit and the uh, the neon's L I Kind of want to know what the voltage across that uh, Xenor Diode now I wonder if it's managed to maintain its uh, 5 volts. Let's probe this live circuit board that's just wobbling everywhere. It's not fun I'll try not to touch it and scream let's bring in the meter and let's see if it's managing to maintain its 5. Vol So there is the negative and there's the positive.

It's gone down to four volts so it is dropping the voltage a bit if it does that, but that is it. Should you have a need to, uh, fix a fan, then this module is available. Not sure how well I' rate it for safety. there is.

There is one thing could happen that would damage the fan. may do something horrible if more than one of these triacs turns on. If it was to crash I Mean it's unlikely, but it could happen, then technically speaking it would. Bridge Let me bring that schematic back in to show you what it would do if it turned on more than one of these tracks.

It would effectively Bridge windings out across the Corde of the motor so to speak and that could actually result in basically, well, a shorted turn effect with a shorted section of windings, guessing that the motors's probably have a thermal fuse in them for if that happens. But um, there is no other protection, but that's just that's fairly common. That's what other units are like too. So there we have it.

it is the Um Universal I. Like the fact that China sells all these Universal modules, also notice this one I've just noticed it now. it says 300 W and 100 W I Bet the 100 wat just as the small TRS but they've This is the luxury version of the big TRX But I like the fact that China doesn't just have these modules. One module that did not arrive it was from AliExpress and unfortunately they didn't ship it in time so AliExpress canceled The order was for a complete Washing Machine replacement control board for Universal use.

It was quite interesting, the only component that wasn't standard in it. It would only drive the washing machine motors that had the Uh, field and and rotor type winding that you basically use a dimmer to control for the speed. But the only thing that wasn't standard about it was that it came with its own water level sensor. So I guess they just it's a bit random what's in machines.

but I Like these modules. I Like the fact that they're geared up to being able to take existing products that have failed electronically and just put in a new control system. a universal module that's a really good, an entertaining thing.