K8041

I have a small problem with this fan timer. It has all been put together by a friend and for the most part is works, the timer and switch have no problems as well the fan does turn on and off delay work. My problem is that the fan will get a “bump” of voltage about every 5 seconds for a fraction of a second when the circuit is off. The led is not turning on and the switch leads are even disconnected. There is also a constant 116v reading on the fan line even before the trigger has been switched. Any ideas would be appreciated.
Thanks Pat

Most likely, it is a very small fan.
Because it is so small, the small amount of power that leaks via the snubber network R17/C7 is probably enough to make it run.
You could increase R17 to e.g. 470 ohm / 0.6W and decrease C7 to 47nF/275VAC/X2

Actually it is powering a small 12v power supply. I also check diode 1 and it seems to have resistance both directions, more one way than the other. While diode 2 seems to be only one direction. Could this be a problem as well?

Hi,

You may want to lift one leg of D1 off of the board.
You maybe reading back through T2 and that might be why you are able to read in both directions.

Ah yes thank you, I will try the other resistor and capacitor and get back to you.
Thanks for the help!

Hey I finally found the resistor and capacitor but the problem is still there. It seems to take longer to before get a jolt of power but still happens about every 10 seconds. Maybe try smaller capacitor and bigger resistor again?
Thanks Pat

Yes, further reducing the cap might help.

Hallo,
Ik hoop dat ik mijn vraag in het Nederlands kan stellen.
Mijn probleem is dat ik de aansluiting SK2 niet aan een fan wil aansluiten maar een 220v ~ relais wil aansluiten,
die 4x wissel bediend. kan dit of heb ik het verkeerde kit gekocht?
Hans

Please: English or French (see forum rules). This is an international forum and we want as many people as possible to benefit from your posts.
Please edit your post.
Thank you.

My problem is that I don’t want to connect a fan to the connection SK2 but a 220v ~ relais will connect,
that 4 x Exchange contacts. Is this possible or have I bought the wrong kit?
I hope it is clear what I mean.
Best regards Hans

Kit has not been designed to drive a relay but you can give it try.
You will have to remove R17 and C7