A circuit includes two thyristors coupled in anti-series. An AC capacitor has first and second electrodes respectively coupled to two different electrodes of the two thyristors. The first and second electrodes are coupled to receive an AC voltage. A control circuit detects discontinuance of application of the AC voltage to the AC capacitor and in response thereto simultaneously applies same gate currents to the two thyristors. A current path through the two thyristors (one passing current in forward mode and the other in reverse mode) discharges a residual voltage stored on the AC capacitor.

A battery charging circuit can include: a primary rectifier circuit configured to rectify an input AC voltage into a rectified voltage signal; a DC-DC converter configured to generate a charging current according to the rectified voltage signal, in order to charge a battery; a control circuit configured to adjust the charging current by controlling an operation state of the DC-DC converter according to a charging requirement, in order to make an average value of the charging current meet the charging requirement; and where the charging current is controlled to be zero when an absolute value of the input AC voltage is lower than a predetermined threshold.

The present description concerns a converter comprising an AC-DC conversion stage comprising a first thyristor, a first power supply circuit delivering a first reference voltage between a first node and a second node, and a second power supply circuit delivering a second reference voltage between third and fourth nodes, the cathode of the first thyristor being coupled to the first node of the first power supply circuit by a first switch and being connected to the fourth node, the second power supply circuit comprising a first rectifying element coupled to the second node of the first power supply circuit and coupled to the third node.

A rectification and boost-buck control system for alternating current, includes a processor, a commutation detection circuit, a chopper circuit and a switch circuit. The chopper circuit includes upper bridge elements connected to corresponding phases of the alternating current. The switch circuit includes lower bridge elements connected to the upper bridge elements. The commutation detection circuit is configured to detect commutation signals. Based on the communication signals and current output current and/or current rectified voltage, the processor is capable of outputting a conduction angle control signal to the chopper circuit and output a switch control signal to the switch circuit to adjust on-off time of the chopper circuit and the switch circuit to thereby adjust the current output current and/or the current rectified voltage.

A switching device is provided. The apparatus includes a switching circuit and a noise filter. The switching circuit is capable of switching a connection destination of a first power conversion circuit other than a second power conversion circuit among the plurality of power conversion circuits between a phase corresponding to the first power conversion circuit and a certain phase of the external power supply. The second power conversion circuit corresponds to the certain phase of the external power supply. In the noise filter, a capacitor is provided on a side of the multiple-phase AC supply of the switching circuit.

Provided are a power supply circuit, a power supply device and a control method. The power supply circuit includes a primary rectifier unit, a modulation unit, a transformer, a secondary rectifier and filtering unit, a current feedback unit, and a control unit. The power supply circuit removes a liquid electrolytic capacitor at a primary side. Moreover, the control unit may determine a type of a voltage of input alternating current, and set a current limit value in the current feedback unit according to the type of the voltage of the alternating current.

A switching power supply device according to an embodiment of the present disclosure includes: power supply circuits corresponding to phases of a polyphase AC power supply as an external power supply; a switching circuit configured to switch a connection destination of another power supply circuit other than a specific power supply circuit corresponding to a specific phase of the external power supply among the power supply circuits to a phase corresponding to the other power supply circuit or the specific phase; and a control unit configured to connect, to each phase of the external power supply connected to the switching power supply device, the other power supply circuit corresponding to the phase, and connect the other power supply circuit as a surplus to the specific phase when the number of phases of the external power supply is smaller than the number of the power supply circuits.

A method of controlling a secondary-side rectifier switch of a flyback converter, can include: detecting a slope parameter of a secondary-side detection voltage along a predetermined direction, where the secondary-side detection voltage is configured to represent a voltage across a secondary winding of the flyback converter; and controlling the secondary-side rectifier switch to turn on when the slope parameter is greater than a slope parameter threshold, and a relationship between the secondary-side detection voltage and the ON threshold meets a predetermined requirement.

The invention relates to an energizing circuit of at least one magnetizing coil of an operational brake, the energizing circuit being configured for energizing the magnetizing coil, which energizing circuit comprises a rectifying bridge connected to the supply network, the output terminals of the rectifying bridge being connectable/connected to the input points of the magnetizing coil,

characterized in that the energizing circuit comprises at least one reduced voltage circuit or external DC supply, whose outputs are connectable via to the to the input points of the magnetizing coil via a controllable operation switch of the energizing circuit. The patent application also comprises claims for a passenger conveyor and for a method.

A power converter including a compressor as a load includes a compensation current output (80) allowing compensation current (Ic), which compensates for leakage current (Ia), to flow. A controller (50) receives a detection signal from a rotational speed sensor (55) which senses the rotational speed of the compressor (CM). When the rotational speed has increased to a set rotational speed at which the leakage current (Ia) is lower than or equal to its limiting value (Lmax) (e.g., the limiting value specified under the Electrical Appliances and Materials Safety Act or by the IEC) in a state where the compensation current output (80) is off, the compensation current output (80) is switched from an on state to an off state. This may reduce the leakage current from the compressor with low power loss.