Electronic circuit controlling a multiple operation apparatus fitted with an electromagnetic mechanism

Claim 1

Control device of an electrical apparatus having a movable contact and an electromagnetic driving mechanism with an electromagnetic coil inducing a change in condition of the movable contact at each time the electromagnetic coil is energized, said control device comprising a power supply circuit to said electromagnetic coil and a control unit inserted in said supply circuit to energize or de-energize the coil, said control unit including a controlable static switch and an electronic control circuit capable of delivering control pulses for the triggering of said static switch for a predetermined time-length T, so as to limit the current supply passing through said electromagnetic coil, said electronic control circuit including: a synchronous pulse generating circuit to trigger said static switch when the voltage of said power supply circuit drops close to zero; a monostable trigger circuit for supplying the pulse generating circuit with a single pulse of time-length T, and; a logic control unit having an output connected to the input of said trigger circuit; said logic control unit comprising a plurality of outputs delivering distinct output signals according to the condition of input signals applied to the input of the logic control unit; and a selector connected between said logic control unit and said monostable trigger circuit to choose the operating mode of said apparatus, the number of positions of said selector being identical to the number of logic control unit outputs.