A load control device for controlling power delivered from an AC power source to an electrical load may comprise a thyristor, a gate current path, and a control circuit. The control circuit may be configured to control the gate current path to conduct a pulse of gate current through a gate terminal of the thyristor to render the thyristor conductive at a firing time during a half-cycle of the AC power source. The control circuit may operate in a first gate drive mode in which the control circuit renders the gate current path non-conductive after a pulse time period from the firing time. The control circuit may operate in a second gate drive mode in which the control circuit maintains the gate current path conductive after the pulse time period during the half-cycle.

A load control device for controlling the amount of power delivered from an AC power source to an electrical load is operable to conduct enough current through a thyristor of a connected dimmer switch to exceed rated latching and holding currents of the thyristor. The load control device comprises a controllable-load circuit operable to conduct a controllable-load current through the thyristor of the dimmer switch. The load control device disables the controllable-load circuit when the phase-control voltage received from the dimmer switch is a reverse phase-control waveform. When the phase-control voltage received from the dimmer switch is a forward phase-control waveform, the load control device is operable to decrease the magnitude of the controllable-load current so as to conduct only enough current as is required in order to exceed rated latching and holding currents of the thyristor.

An electronic system and method include a controller to actively control power transfer from a primary winding of a switching power converter to an auxiliary-winding of an auxiliary power supply. The switching power converter is controlled and configured such that during transfer of power to the auxiliary-winding, the switching power converter does not transfer charge to one or more secondary-windings of the switching power converter. Thus, the switching power converter isolates one or more secondary transformer winding currents from an auxiliary-winding current. By isolating the charge delivered to the one or more secondary-windings from charge delivered to the auxiliary-winding, the controller can accurately determine an amount of charge delivered to the secondary-windings and, thus, to a load.

The present disclosure relates to a multi-voltage driving control method, apparatus, and device, and a computer-readable storage medium. The multi-voltage driving control method includes the following steps: obtaining a voltage sample of a mains supply, and determining a voltage region corresponding to the voltage sample; determining a driving circuit corresponding to the voltage region according to the voltage region and a default working voltage region; and controlling an electrical appliance to operate by the driving circuit. According to the multi-voltage driving control method provided by the present disclosure, a working voltage range of a mains supply is determined by detecting the mains supply in an electricity use environment; a working state of a circuit is dynamically adjusted according to a change of an input voltage of an electrical appliance, thereby achieving stable work of the electrical appliance in a multi-voltage environment.