Hi,
I have a circuit board for a fan delay that has burned out two resistors.
I have drawn the circuit diagram and included it here.
I think it works by closing the switch, this energises the relay and turns the light on (it would run the fan but I have put a light in the circuit here).
When the switch is opened the relay remains closed for a time determined by the potentiometer, as much as 15 minutes I think.
There may be other components burned out but I don't know the values or R3 or R7. could someone help me if they have an idea what the values might be?
An explanation as to how the circuit works would be a great help, I could then follow the signal through the circuit if something else has burned out.
Thank you.
Bob.
There is a possibility I have made an error with my drawing but I have checked and rechecked it.

 

Check the transistor connections again. The relay coil should not be connected to the base.

 

Yes you are right. The BC182LB has an unusual configuration emitter, collector, base.
I have altered the drawing.
I have tried to simulate the circuit in circuit wizard but it fails to put any voltage across the relay coil no matter what resistances I use for r1 and r7.
Is it possible that circuit wizard is not capable to running a simulation with an AC supply?
Would someone mind telling me what the resistances for r3 and r7 are likely to be. They have both burned completely out on the circuit.

 

R3 says 1M which is 1Meg Ohm and R7 says 1 so I would assume it is 1-Ohm. A little late so I don't know if you even need this any more.

 

The circuit uses a capacitive reactance power supply to make DC directly from the 240v AC mains.

The forum rules state that we are not allowed to discuss this type of circuit because of safety issues.

You have also made a few mistakes in drawing the circuit (twice), which does not help the safety argument because it shows that you may not understand the circuit (which is dangerous)...

Moderators will probably close the thread.

 

Hello,

I am closing this thread as it violates AAC policy and/or safety issues.

Quote:
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• Any kind of over-unity devices and systems
• Automotive modifications
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