Built your own split system?
 

They have these new gizmos now, and they look interesting..

Universal Split Air Conditioner Control System A/c Control Board - Buy Air Conditioner Control System,A/c Control Board Product on Alibaba.com

"Universal split air conditioner control system a/c control board"..

Amazon.com: Universal Deluxe AC Control System Replacement For Minisplit Ductless AC: Electronics

"Universal Deluxe AC Control System Replacement For Minisplit Ductless AC"
http://ecx.images-amazon.com/images/I/41NaKu-mTsL.jpg


Someday, they'll make one to work with an Inverter system..

Sir, you just made my day. I'm buying one of these TODAY to stick on my current beast.

Not eligible for prime shipping, which means it's not coming from an amazon warehouse.
Tell you when it gets here.

Good luck with being the 1st on your street to try one.. :)
(We were first to own a microwave oven, on our street).. ;)

I was thinking if the loads are too big, maybe other relays or SSR could be subbed.?.

I'm trying out some meds (for the tree pollen).. Wife's birthday dinner tonight.. No beer.. :(

I saw one of those units (Chinese site) that said it had "Reset" as a selling point.
Maybe it was a power-fail-restore type thing..

Looks like the control has 30 Amp contactors for compressor and aux heat, 7 Amp sugar cube relays for everything else. Main thing I'm worried about is what comes out of the relays? Line voltage? 12VDC? Neutral? My guess is it switches one line leg, like your Sanyo control board. In that case, I will have to either switch coils on my reversing valve or use a doorbell transformer to get 24VAC. Maybe I'll get lucky and the designers put low voltage coming out for the reversing valve.

Found a close-up shot of what should come in the box:
http://www.teamwork.com.sg/Thumbnail...%20QD-U12A.jpg
I wonder why the wall and remote controls don't match? Maybe they had extra Hayashi remotes that week.

I'm not a licenseded HVAC tech, but I think I am certificated enough to install this device.

I have my fingers crossed that all 3 temp sensors will be in the box (ambient, pipe, defrost). The unit description says it does, but you never know...

In other pictures, it seems like two sensors were copper and one was black encapsulated.
U12A Universal air conditioner control system with PCB, wall mounted control and remote control

The "instructions" are just a couple of pictures..
The 4-way valve on my Sanyo is 230vac.. So, it seems like you should be able to use a step-down transformer. See Ebay..

The package came in the mail today. USPS Priority Mail from Hollywood, Florida. Yay! I don't know where the pics and such came from, but the stuff in the box I got looks just like the label on the box. And it did come with three sensors. No batteries for the remote control, though.
http://ecorenovator.org/forum/attach...m-imag0136-jpg
Top view of the control board
http://ecorenovator.org/forum/attach...6&d=1462569568
The two chips on top of the board are identical. They are buffer chips that are being used to control all the relays and the swing motor. Just about the same as any random window shaker unit.
http://ecorenovator.org/forum/attach...1&d=1462568921
Checking the bottom of the control board reveals that everything is switched by one line of the power cord. This means I will have to conjure a way to make it run correctly.This also means it can run off 110 or 220 Volt (or both with relay mods for a couple bucks...) line power. If the board was transplanted into something like Xringer has, but with a single speed compressor, it could very well need no extra work besides wiring. The chip on the bottom is the embedded controller. Someone could probably find a programmable controller with the same pinout as this chip if they looked.

Got the unit rigged up today. I have some accommodation to do.
Before shot of the victim: a whirlpool 1 1/3 ton twisty knob window unit with reversing valve added.
Attachment 6937
The thing wired up dead easy. No cutting wires or crimping connectors at all. Basic wire color coding / matching skills required. Once it got turned on, I figured out a problem: the reversing valve is active in heating instead of cooling mode. So it is trying to cool in heating mode and vice versa. Like I said, a cheap (or maybe free, if the on-board reversing valve relay has a normally closed contact) relay mod will change that. If I hadn't lost that coin toss, I would have had a "correctly" operating unit without any extra work.
Attachment 6939
I tapped into the other hot line for the "neutral" connection for the board. I had to run one extra wire: a "neutral/ground" wire to the doorbell transformer I am using to energize the reversing valve. All I have on hand is 110/24 volt doorbell transformers.
Attachment 6940
I ran out of free time today, so I left the unit in its current state of almost working perfect. Still haven't looked for remote batteries yet.

EDIT: I did a little research today, and found that the sugar cube relays in this controller (HRW-112LM1) are form A, which means SPST normally open contacts. I will either have to find a replacement relay that is form C (SPDT contacts) and swap the RV relay or rig in a logic inverting transistor to make it do what it should.

OK, so I rigged my countermeasure in today. I found a few relays, but they were all the wrong size to fit in the board. I robbed an NPN transistor out of one of the donor boards ( a PN2222a, Fairchild equivalent of 2N2222) and rigged it between the micro and the relay driver IC. I desoldered the input pin from the board and filled the gap with super glue. I found a good ground on the board (hole for a capacitor not stuffed) and stuck the emitter of the NPN in it. I tacked a 10K resistor between the micro output pin for the RV and the base of the NPN. I twisted the end of a leg of a 1K resistor around the driver IC pin previously desoldered and removed it. I melted a teeny blob of solder into the eye and tacked it onto the end of the pin. I twisted and tacked the leg around the NPN collector, then ran the other leg of the resistor to a regulated 5 Volt hole in the board (other leg of the capacitor not stuffed: C5 next to U3). See pics in previous post for reference.

Long story short, the transistor did its job. The thing cools in cooling mode and heats in heating mode. Got everything stuffed back inside the unit, secured parts with screws, and set it to cool the outdoors while I washed my car. I took some pics, but they all ended up smeared or out of focus enough not to be proud of. The awesome thing today was finding out the control panel in the kit is nearly exactly the width of the bezel for the twisty knob plate. Plus I found some batteries for the remote control and played with the unit that way.

Sooooo, what does this do?

Iamgeo,

I believe the main, original intention of the manufacturer was to provide an inexpensive solution for window and mini-split owners whose units have suffered a control board failure, keypad failure, struck by lightning, etc. Original, factory control boards are very expensive to replace. Complete system replacement even more not cheap.

Xringer experienced one of these failures recently, and the cheapest, refurbished control board available for his unit is around 300 to 400 dollars (depending on the source). A whole new system is in 4 figure territory. This line of controls will not work with his system, because he has a variable-speed compressor. These controls will only work with single-speed compressors. I'm really glad he shared the link, as this type of control is perfect for the hacked heat pumps I tinker with.

I finished up the install today (for now). I also heated and cooled the outdoors a little to get an idea of how this control functions.

It looks like this now:
http://ecorenovator.org/forum/attach...4&d=1462754456
I stuck the control panel and a piece of coroplas to the metal cover plate that now covers the new guts. I stuck the remote control to the coroplas with a piece of velcro. Now it is ready to live another lifetime in a new window or wall.

I played around with the remote control, and figured out it doesn't sync with the main unit until you change modes. It has 5 modes: cool, dehumidify, auto, fan, and heat. In heat mode, you have to use the remote to disable or enable aux heat vs. heat pump. In auto mode, you have to set the temperature on the control panel. Changing the temperature with the remote does nothing in auto.

I figured out the unit also has a predictive temperature control loop of some kind built into it. I originally had the thermometer (black plastic covered sensor) fastened to the indoor coil with romex nail clips like most of the window units do. The heating or cooling of the coil would throw off the temperature a little due to the close proximity. Rigged this way, when I set the unit close to the outdoor temperature, the unit did not shut off exactly when the setpoint was reached. The unit would run for a minute or two and overshoot the target temperature a bit. When the compressor cut off, the blower ran for a minute or more. After a couple of these cycles, the sensor was very close to the setpoint by the time the fan shut off.

Ok. Now I understand.

I was looking through qunda's website and found this:
http://www.qunda.com/images/kz/06-1.jpg
Model no. QD30
Inverter air conditioner control panel

Seems smallish. Maybe for a 9,000 BTUh system?

Group of QD30 inverter air conditioner control panel general purpose inverter inverter air conditioning control system modification

https://img.alicdn.com/imgextra/i4/8...!!87286379.jpg

Not seeing where the IDU connects up.. Or even how that could work..?.

https://img.alicdn.com/imgextra/i4/8...!!87286379.jpg

From the description page, this is a versatile control that ccould be rigged a number of ways. It is a slave module that seems to be able to use a number of control modules as an input. It can take a common on/off command or who knows what kind of speed signal. I wish i could read Chinese.

Whatever input signal it takes, it responds by supervising the compressor. It has some thermistor thermometers that I imagine you would fasten to the rig to tell the control board what is reacting how. The chip next to the bridge rectifier looks a lot like the one inside the sanyo that died...high voltage and pwm signal goes in, 3 phase drive signal goes out.

CN2 looks like it's got frequency step input controls. 5 or 10 Hz up or down. And a common / ground?
Still not seeing the comm line to the IDU.
So maybe those Up & down lines get bumped by a controller that runs the IDU? fed by IR remote..
Or maybe the IDU runs as a Stand-alone, using Fan-mode? (Sanyo IDU works in Fan, without anything but 230vac)..

Is CN3 the 4way-valve control line?? :confused:

Maybe I can get someone to translate some of this for us. I'll post if I get any info.

New link: https://www.aliexpress.com/item/32956162411.html

They are making some interesting pcbs these days.. Inverter support!

Universal DC Inverter control system for split air conditioner QD82 Drive strong DC compressor/outdoor/indoor DC fan motor/electronic expansion valve

Scroll down the page to the wiring details...


Amazon has the QD81B version.. https://www.amazon.com/CHUNGHOP-Univ.../dp/B07S89QC4S

I was just snooping around, and found this thread because it looked interesting.

Maybe I don't know what I'm talking about but, this link https://www.amazon.com/CHUNGHOP-Universal-Controller-Conditioner-Conditioning/dp/B07S89QC4S states that the controller is at a fixed frequency, and therefore no longer an inverter A/C unit. (for Xringer)

Because of the DC motor design, the boards have to be 'inverter' type controllers.
But, the frequency of the controlling clocks (which controls the RPMs of the motors) will become fixed. The OEM boards vary the RPMs, thus control the amount of power being used.
My Living room Unit will use 1200w when it starts and then drop down to 470w after the room starts to cool. Then will drop to just a few watts when the room is at target temp.

Buying one of these 24k BTUh replacement boards is risky, because it might run the old Sanyo at a full 24k BTUh, sucking down full power until the thermostat shuts it off. Meaning it would work a lot like Old-Tech USA HVAC.
Not really desirable, but maybe better than nothing.
What would be great, if one could manually adjust the Fixed frequency. Make it run at RPMs in a lower power range. Like 400 to 800 watts.
Which would never deliver the full 36k BTUh heating or 24k BTUh cooling the Sanyo hardware is capable of, but it would be satisfactory for the average day.

Running this old Sanyo at full RPMs, would work. But, because it can produce almost instant cooling or heat in a large area. It might easily over-heat or cool rooms real fast. Blasting out 36,000 BTUh of heat when only 12,000 are really needed.. LOL!
(Spec on 24k Sanyo is 24k cooling and 36k BTUh heating)..

Cheers,
Rich

Thanks.
I wish that I understood the systems. In my mind it should be easy to configure an Arduino or RPi to receive the clock signal and vary an output to drive an SSR (or several) all whilst watching a temp sensor. :)Anyway, I will back out now before making a mess of the situation.:o

I think the indoor unit uses an AC motor on some of these M/S systems. My Sanyo uses a DC 280 volts, 47W brushless in the indoor fan. At least that's what the label says on the replacement motor.

But the two motors in the outdoor unit (fan & compressor) have their own DC controllers.
I think they might work like the brushless motors used in RC airplanes. (but don't quote me on that)! https://youtu.be/bCEiOnuODac
Anyways, both motors use feed-back from some type of speed (RPM) sensors to control their speeds, and the main-board CPU sets those speeds based on feed-back signals from the outdoor & indoor unit temperature sensors and the indoor thermostat.

In other words, it's not simple to run the hardware without some smart firmware.. :)
I would like to learn more about how these things work, but I've got way too much other stuff on my plate these days.

Cheers,
Rich

What he said...

A lot of the variable capacity mini-split systems have brushless DC motors inside the pot. Most have 3 phase stators and a permanent magnet rotor. The control systems are all somewhat proprietary, custom matched to a particular brand of compressor.

Most of the compressors work just like a front load washer or treadmill motor: high power DC is switched in and out of the circuit in a manner that makes the motor turn. Older models use some sort of rpm sensor for feedback, newer models monitor the motor current and back EMF to determine position and speed.

For a good read on this type of system, look up NXP document AN5387. It's for a refrigerator, but the strategy is the same. A lot of the newer mini-split compressors are double-stacked as well: 2 compression stages in one shell (Mr. Slim, hyper heat,etc.).

thanks for the new gizmo sir,

by the way is it available on EBay? or any online store? thanks in advance

The search terms might be too convoluted for Ebay..
This link Aliexpress is still okay.. https://www.aliexpress.com/item/32956162411.html

I know its not 100% related to the thread but did you spot any controller for air source water heater thta could be used for hydronic? I try to convert one (alredy a air source water heater) but the temp is limited since its a pool heater. My machine is not inverter technologie.