Abstract: A circuit for controlling a bidirectional switch referenced to a first reference voltage by a control circuit supplied by a first voltage and referenced to a second reference voltage. The supply voltage of the control circuit is connected by a diode to a coupling circuit comprising a node, this node being connected to the collector of an NPN transistor having its emitter connected to the second reference voltage and having its base receiving the output of the control circuit, to a first terminal of a capacitor having its second terminal connected to the first reference voltage, to the emitter of a PNP transistor having its base connected to the collector of the transistor, and having its collector connected to the control terminal of the bidirectional switch.

Abstract: A method and a circuit for controlling a triac intended to be series-connected with a resistive element of positive temperature coefficient or which is at least capacitive, and a winding for starting an asynchronous motor, for supply by an A.C. voltage, the present invention including the steps of: detecting a voltage representative of the voltage across the series connection of the element and of the triac; comparing this detected voltage with respect to a threshold; and blocking a turning back on of the triac when the threshold has been exceeded.

Abstract: A power dimmer for an A.C. load comprising, between two terminals, two one-way switches connected in anti-parallel and controllable to be turned off and turned on, each switch being controlled by a driver circuit setting the turn-off times of each of the switches with respect to a reference value, each driver circuit being associated with a supply circuit comprising a voltage storage element in series with a one-way rectifying element, all in parallel with a voltage-limiting element, the two supply circuits being connected to each other by a capacitor and the respective supply voltages of the driver circuits being sampled across the respective capacitors of each supply circuit.

Abstract: A capacitive power supply circuit, comprising a power storage element between two output terminals for providing a rectified output voltage; in series between a first input terminal for applying an A.C. voltage and a first of the output terminals, at least one capacitor and a first diode; a switch controllable by application of a signal on a triggering terminal; and means for controlling said switch to the on state when the output voltage is in a predetermined range of values.

Abstract: A circuit for controlling the power in a load supplied by an A.C. voltage and directly connected to a first terminal of application of the A.C. voltage, including two isolated-gate bipolar transistors, connected in anti-parallel between a second terminal of application of the A.C. voltage and the load; circuitry for detecting the zero crossing of the A.C. supply voltage in a first direction; circuitry for generating, at each period of the supply voltage, a pulse of predetermined duration for controlling a first one of said transistors, the time of occurrence of the pulse being conditioned by the detection of the zero crossing of the A.C. voltage and by a desired power reference setting a variable delay of occurrence of the pulse with respect to the detected zero crossing; and circuitry for inverting and transferring said pulse to the second transistor.

Abstract: A circuit for detecting an overcurrent in an element in which an A.C. supply current flows, including a first comparator, assigned to the halfwaves of a first sign of the A.C. power supply, receiving on a reference input a first reference voltage setting a first one of the thresholds, a second comparator, assigned to the halfwaves of a second sign of the A.C. power supply, receiving on a reference input a second reference voltage setting a second one of the thresholds, and an input stage providing, to respective interconnected read inputs of the comparators, a voltage proportional to the voltage across the element, the stage including at least one first resistive element introducing a voltage drop between a first one of the terminals of the element and the read inputs.

Abstract: A power dimmer for an A.C. load including, between two terminals, two one-way switches connected in anti-parallel and controllable to be turned off and turned on, each switch being controlled by a driver circuit setting the turn-off times of each of the switches with respect to a reference value, each driver circuit being associated with a supply circuit comprising a voltage storage element in series with a one-way rectifying element, all in parallel with a voltage-limiting element, the two supply circuits being connected to each other by a capacitor and the respective supply voltages of the driver circuits being sampled across the respective capacitors of each supply circuit.

Abstract: A circuit for controlling a bidirectional switch referenced to a first reference voltage by a control circuit supplied by a first voltage and referenced to a second reference voltage.

Abstract: A circuit for detecting an overcurrent in an element in which an A.C. supply current flows, including a first comparator, assigned to the halfwaves of a first sign of the A.C. power supply, receiving on a reference input a first reference voltage setting a first one of the thresholds, a second comparator, assigned to the halfwaves of a second sign of the A.C. power supply, receiving on a reference input a second reference voltage setting a second one of said thresholds, and an input stage providing, to respective interconnected read inputs of the comparators, a voltage proportional to said voltage across the element, the stage including at least one first resistive element introducing a voltage drop between a first one of the terminals of the element and the read inputs.

Abstract: An analog voltage pulse generator, including a first break-over component of Shockley diode type to activate a rising edge of a pulse on an output terminal and a second component of thyristor type to block the first component and deactivate the pulse.

Abstract: The present invention relates to a bidirectional switching circuit including, in series, a bidirectional switching element controllable to be turned off and turned on, and a bidirectional conduction element forming a dipole and automatically selecting the conduction direction.

Abstract: An analog voltage pulse generator, including a first break-over component of Shockley diode type to activate a rising edge of a pulse on an output terminal and a second component of thyristor type to block the first component and deactivate the pulse.

Abstract: A circuit is provided for supplying a load from an AC voltage supply. The circuit includes a control circuit and a bidirectional switch coupled in series with the load. The bidirectional switch includes two one-way switches connected in antiparallel, and the control circuit controls the bidirectional switch based on a relatively low DC voltage. The bidirectional switch is connected to a first terminal of the AC voltage supply, and the DC voltage is referenced to the first terminal of the AC voltage supply. Additionally, an apparatus connected to an AC voltage supply and a relatively low DC voltage is provided. The apparatus includes a control circuit, a load to be supplied by the AC voltage supply, and a bidirectional switch coupled in series with the load. The bidirectional switch includes two one-way switches connected in antiparallel, and the control circuit controls the bidirectional switch based on the DC voltage.