I'm looking to specify (well, suggest) a RC snubber network for someone over on diy.se who is having EMI problems with his ceiling fan knocking out his TV briefly on turn-off:
Thing is, I cannot find any information on the winding resistance and inductance of a garden-variety ceiling fan motor. Is this something I'd have to measure myself, or has this ever been specified or measured for a typical US ceiling fan motor?
EDIT for those who haven't read the link: the fan turning off causes the TV screen to go blank (no picture) for a few seconds, but the TV stays powered all the while.
Best Answer
I recommend you use a 1uf (or larger) 150v AC, capacitor across the motor power leads (no resistor needed). This should help suppress the electrical noise but since your problem started about 3 months ago, that tells me that something changed 3 months ago. Possible changes:
1 - new TV
2 - new cable box
3 - cable box moved and plugged into the same circuit as the fan switch
4 - fan motor grounding disconnected
5 - if fan has internal noise suppression, it went bad