Remote Fan Controller (IR)

The reciever most likely has failed parts. This is not something you will be able to service yourself unless you can have a means and the skills to troubleshoot it. I am sure that the manufacture does not support service for this type of unit because of the service cost. If you can find out the manufacture of the particuler receiver you have, you may be able to buy a new replacement, if the cost is feasible. If you contact the dealer where the fans were bought, they may be able to give you a contact for spare parts.

Jerry G. ======

I wonder whether the fan is generating enough noise to crash the microcontroller? Perhaps a suppressor has gone, or the power supply drops out enough to crash it when the fan's running? I'd look at the supply rails on a scope to see what happens.

Just a thought...

Theo

Hi Theo

I thought about the Fan generating too much noise, but I get the exact same result with just the light connected. (Removed the Live to the Motor).

So it seems to be something else. I have checked the 3 main caps with a normal ohm meter, and they seem to be ok (with the value increasing up to a point, reverse the polarity of the test leads, and the value again increases to the same point).

I do not have an ESR meter though, so if somebody thinks it is the caps, then I will go and sub them.

The unit costs about R280.00, ($37US), and >> The 3 have the problem as follows:

Ok, Step further now. With both the fan and light disconnected (but power applied), checked with a DC Voltmeter the voltage going to the IR receiver (and the single chip on the controller board). Getting a nice stable 6 volts.

But when i press a button to turn the fan on, the voltage drops to about 3 volts (within 2 seconds). During the time that the voltage is dropping, the receiver still responds. but after that 2 sec time, it no longer responds.

There is 1 transistor that runs the light circuit, and 3 transistors for the fan circuit. Pulling the 3 fan transistors, and then trying, the voltage does not drop, and the receiver keeps on responding.

Looks to me like the trannies are drawing to much power, and loading down the low voltage.

The circuit does not have any transformer, so it looks like it has another way of reducing the mains voltage down to the 6v.

I have replaced all the caps I had stock of, and all the resistors check within range. Can anybody venture at a guess of whether there is a problem in the tranny stage, or in the power reducer (not being able to supply current under the load of the chip driving the trannies)

Thanks P

The power supply is probably a mylar capacitor and a zener diode. Try changing that capacitor, if it's bad, the psu cannot supply enough current.

Hi All. Here is a controller that is highly similar to the one that I am talking about :

BTW James, If I substitute the cap, do I have to use a mylar (during the test), or will any cap with the same voltage and cap rating work? I have not seen a Zener on the board (though the places that are marked for Zeners have resistor-like components in them - do they do zeners that look like resistors?)

I have tried googling the powersupply as you have suggested it is, but cannot find any more info on it. Does anybody have a proper name for it ?

Peter

Looks like the Cap (0.6uF I think) and the 48v Zener are in parallel. Am I looking at the right part of the cct?

Also, if it is the right part, how does the voltage get down to 6v for the IR Detector and Chip?