Abstract:
An AC/DC converter includes a first terminal and a second terminal for receiving an AC voltage and a third terminal and a fourth terminal for delivering a DC voltage. A capacitive circuit is connected between the third and fourth terminals. A rectifying bridge circuit has input terminals respectively coupled to the first and second terminals and has output terminal respectively connected to the third and fourth terminals. An inductive element is coupled in series with a first switch circuit between the first terminal and an input terminal of the rectifying bridge circuit.
Abstract:
A control circuit varies the power of a load powered by an alternating voltage, comprising: a first thyristor and a first diode connected in antiparallel between first and second nodes, the cathode of the first diode being on the side of the first node; a second thyristor and a second diode connected in antiparallel between the second node and a third node, the cathode of the second diode being on the side of the third node; third and fourth diodes connected in antiseries between the first and third nodes, the cathodes of the third and fourth diodes being connected to a fourth node; a transistor between the second and fourth nodes; and a control unit for controlling the first and second thyristors and the transistor.
Abstract:
A rectifying circuit includes a first diode coupled between a first terminal configured to receive application of an A.C. voltage and a first terminal configured to deliver a rectified voltage; and an anode-gate thyristor coupled between a second terminal configured to receive application of the A.C. voltage and a second terminal configured to deliver the rectified voltage, wherein an anode of the anode-gate thyristor is connected to the second terminal configured to deliver the rectified voltage.
Abstract:
A control circuit varies the power of a load powered by an alternating voltage, comprising: a first thyristor and a first diode connected in antiparallel between first and second nodes, the cathode of the first diode being on the side of the first node; a second thyristor and a second diode connected in antiparallel between the second node and a third node, the cathode of the second diode being on the side of the third node; third and fourth diodes connected in antiseries between the first and third nodes, the cathodes of the third and fourth diodes being connected to a fourth node; a transistor between the second and fourth nodes; and a control unit for controlling the first and second thyristors and the transistor.
Abstract:
A rectifying circuit includes a first diode coupled between a first terminal configured to receive application of an A.C. voltage and a first terminal configured to deliver a rectified voltage; and an anode-gate thyristor coupled between a second terminal configured to receive application of the A.C. voltage and a second terminal configured to deliver the rectified voltage, wherein an anode of the anode-gate thyristor is connected to the second terminal configured to deliver the rectified voltage.
Abstract:
A circuit capable of receiving, in series with at least one light-emitting diode, a rectified A.C. voltage, comprising: a first gate turn-off thyristor connected to first and second terminals of the circuit; and a control circuit for turning off the first thyristor when the voltage between the first and second terminals exceeds a threshold.
Abstract:
An AC/DC converter includes: a first terminal and a second terminal for receiving an AC voltage and a third terminal and a fourth terminal for supplying a DC voltage. A rectifying bridge includes input terminals respectively coupled to the first terminal and the second terminal, and output terminals respectively coupled to the third terminal and fourth terminal. A first branch of the rectifying bridge includes, connected between the output terminals, two series-connected thyristors with a junction point of the two thyristors being connected to a first one of the input terminals. A second branch of the rectifying bridge is formed by series connected diodes. A control circuit is configured to generate control signals for application to the control gates of the thyristors.
Abstract:
An AC/DC converter receives an AC voltage at a first terminal and a second terminal. A rectifying bridge has a first input terminal coupled via a resistive element to the first terminal and a second input terminal connected to the second terminal, with output terminals of the rectifying bridge coupled to third and fourth terminals of the converter for generating a DC voltage. A first controllable rectifying thyristor couples the first terminal to the third terminal and a second controllable rectifying thyristor couples the fourth terminal to the first terminal. The resistive element functions as an inrush protection device during a first phase when the thyristors are turned off. In a second phase, the thyristors are selectively actuated.
Abstract:
A rectifier bridge circuit includes a first SCR/IGBT switch and a second SCR/IGBT switch coupled to a circuit input to receive an ac input voltage. The first and second SCR/IGBT switches are alternatively switchable to generate a rectified voltage at a circuit output. Control currents coupled to control terminals of the first and second SCR/IGBT switches are power supply sourced from an auxiliary dc source generated by rectifying the ac input voltage. The control currents are generated by current sources coupled between the auxiliary dc source and the control terminals of the first and second SCR/IGBT switches. The current sources are selectively activatable to produce gating currents for switching on and off the first and second SCR/IGBT switches. A controller unit is provided to control the current sources via level shifter circuits. The control implements progressive conduction time of the first and second SCR/IGBT switches so as to provide inrush current limitation.
Abstract:
A circuit can be used for charging a capacitor with an AC voltage. In one embodiment, the circuit includes a capacitor coupled to be charged with the AC voltage. An adjustment is configured to adjust a capacitor charge speed according to a value of the AC voltage. The adjustment circuit includes at least one bipolar transistor coupled to receive a voltage at a base of the bipolar transistor. The voltage is a function of the value of the AC voltage.