CHATTER PREVENTING DEVICE

PROBLEM TO BE SOLVED: To provide a chatter preventing device of relatively simple constitution, by providing a chatter detection means based on a maintaining time of an opening/closing condition of a magnet switch contact and a control means of a power source based on a detection signal of this detection mess. SOLUTION: When chattering is generated in a magnet switch 52C, opening/ closing of a contact are repeated, a time maintaining an opened condition (or closed condition) is shortened. This maintaining time is detected by a chattering detection means formed by a CR charging circuit 14 and an OR gate IC1, a chattering generation detection signal is output to a control means comprising a compressor driving relay 1Y, self holding relay 1X, etc. In the control means, based on a detection signal, power supply to a drive circuit of the switch 52C is stopped. As a result, the switch 52C is not energized thereafter, so that the switch itself and a connection equipment can be protected.