Patent ID: 8339761
Filing Date: 2012-12-25
Classification: H01H

Abstract:
1. A relay failure detecting device in a relay output circuit that is provided with a plurality of relays that, when not driven, connected between a common terminal and a normally-closed terminal, and that when driven, connected between the common terminal and a normally-open terminal, where the individual common terminals of the relays are connected individually to the plurality of outputs terminals in an alternating current power supply, and the individual normally-open terminals in the relays are connected individually to a plurality of power supply input terminals; comprising: a dummy load that is driven by the alternating current power supply through a diode, between the individual normally-closed terminals of the plurality of relays, and that is provided with an evaluating device evaluating, from the state of operation of the dummy load, whether or not there is a failure in the plurality of relays when the plurality of relays is not driven.