What kind of switch can I buy?

Question

to make an electric circuit turn off and on 10 times a second? (for an appliance)

Answer 1

Switch? I think your needs would be better served with some kind of a counter IC which shunts current with a solid state relay when it reaches a certain number denoting a period of time, then reopens after a set period of time. Should be pretty easy to build with some of those jellybean ICs and transistors that have been best sellers since the time of the Carter Administration, but I can't help you with a schematic or anything.