Photoelectronic safety device

Claim 1

In a photoelectronic safety device for disconnecting a user apparatus from a supply line by means of a remote-control switch when faults or irregularities arise in the line, the user or the safety device, the combination comprising: photoelectric means connected to the supply line and including at least three lamps star connected and shunted across said supply line, the star center of said star connection of said lamps being grounded, and at least three photoresistances connected together in series and each facing one of said lamps, said photoresistances being responsive to the light signal emitted by said lamps and to the variations of said light signal, an electronic controlled switch including a TRIAC having a gate connected to one end of said series of photoresistances and an anode connected to the other end of said series of photoresistances, a relay connected between said anode and said supply line and controlled by said TRIAC, a control circuit including a switch controlled by said relays, a manually operable push button, a contactor and a coil for operating said contactor, said contactor controlling said remote control switch provided on said supply line, and said coil being connected between said push button and the cathode of said TRIAC, and adjustment means for said lamps for adjusting said light signal emitted by said lamps and determining the level of sensitivity of the device.