Bassbinotoko Distortion should be less than 1% if the pots are adjusted correctly. And if the mystery brand 8038 chip behaves the same as the original Intersil ICL8038.

Bassbinotoko RP3 adjusts the duty cycle, but it's only intended for trimming the sine or triangle distortion. You'll have to calculate or experiment with the values of RP3, R5 and R6 if you want greater range.

Bassbinotoko This is a very basic projector model that was discontinued in 2018. No DVI or HDMI inputs, just analog VGA and RCA composite video, like a projector from 20 years earlier. It has no "smart TV" or media player capabilities at all.

Bassbinotoko Some semi-pro AV gear like camcorders and VCRs can be configured to respond to different remote codes. That's probably not the case for air conditioners. You probably also don't want to open up the AC and wire relay contacts from a Sonoff switch across the switches on the control panel. Or modify the BW-RC02 with two remote IR blasters and add a Sonoff relay to select between them. So, there's two more reasonable options: get a second BW-RC02 and position it so it only controls the one air conditioner (and the AC can't receive signals from the first BW-RC02). Or, swap one of the air conditioners for a different make or model from somewhere else in your home.

Bassbinotoko It's not a thermistor. It contains an imperfect copy of a DS18B20 digital temperature sensor.

Bassbinotoko 5 amps should be plenty of current. Lower voltages are OK if you don't need high power for thick wires or double-sided boards with large copper areas. I've used a T12 iron at 12V (from a battery) and it worked fine. I've seen comments that the voltage regulators in some T12 soldering controllers overheat if you run them at 24 volts, so to be safe I use a 19V laptop power supply.

Bassbinotoko Maybe 15 watts, since it's barely half the area of a name brand 25W panel. I'd consider this for a camping trip where flexibility and light weight were more important than power output and long life.

Bassbinotoko That would require an inverter to convert the battery voltage to 230V 50 Hz. I wouldn't advise using the same type of sockets and plugs for 12V DC devices as for 230V things, unless you lived deep in the forest where no grid AC power was available, and the only appliances were 12V DC.

Bassbinotoko The controller regulates the charging of a 12V lead-acid battery. It provides a couple of USB charging outlets, and a voltmeter which displays the battery voltage. It can be set to automatically turn lights on when it gets dark, then turn them off again at dawn or after a certain number of hours. The 10 amp controller is fine for panels up to at least 100 real watts.

Bassbinotoko I don't know. The relay in mine is a "Golden" brand, GI-1A-5DH, 10A 250VAC. Extrapolating from the rating on a different relay in my junkbox, it might be OK for a 0.125 HP motor at 120V, or a 0.25 HP motor at 240V. To be on the safe side, I'd prefer to use the Sonoff to energize a much bigger relay (aka contactor, motor starter) that has a bigger current and HP rating.

Bassbinotoko If by some chance you did receive the US power supply, all you would need is an adapter plug (not a transformer) since the US supply is rated for 100 to 240 volts, 50-60 Hz.

Bassbinotoko If they are installed in parallel (69 style), the iron will be more sensitive to movement.

Bassbinotoko There's a spot (with a jumper across it) for a blocking diode. I'm considering adding a Schottky rectifier salvaged from a scrapped circuit board, but the best option might be an "ideal diode" (or anti reverse irrigation) module.

Bassbinotoko If you can resist the temptation to turn the volume up all the way, a 10 amp, 12 volt supply should work. If you want it to play louder, either use a spare car battery hooked to a trickle charger, or try the ATX power supply from a discarded computer (google how to do that).