Light-dimming device includes: first and second terminals; switch including switching device connected between terminals; adjuster for varying conduction angle of switch; controller for controlling switch and power supply module for supplying power to controller. Controller includes zero-cross detection circuit for detecting zero-cross of AC voltage, control circuit for generating PWM signal of on-duty ratio corresponding to conduction angle from adjuster, and driver circuit for turning device on and off by PWM signal. Controller allows device to conduct and then turn off within variable period of time, from start of half cycle of AC voltage, shorter than half cycle. Circuit starts generation of pulse in PWM signal when prescribed period of time, shorter than variable period of time, from zero-cross of voltage elapses.

An electronic device is disclosed for controlling a high-voltage power source with multiple low-voltage switches. The electronic device includes a low-voltage DC power supply that allows for low-voltage wiring and components to be used to control the high-voltage power source using multiple low-voltage switches. The electronic device includes a single pulse generator that generates a pulse signal upon activation of any one of the multiple switches. The pulse signal activates a bistable circuit controller that is coupled the a high-voltage electronic switch to control high-voltage power to the load.

An electronic device is disclosed for controlling a high-voltage power source with multiple low-voltage switches. The electronic device includes a low-voltage DC power supply that allows for low-voltage wiring and components to be used to control the high-voltage power source using multiple low-voltage switches. The electronic device includes a single pulse generator that generates a pulse signal upon activation of any one of the multiple switches. The pulse signal activates a bistable circuit controller that is coupled the a high-voltage electronic switch to control high-voltage power to the load.

A power supply unit for use with thermostats or other like devices requiring power. A power supply unit may be designed to keep electromagnetic interference emissions at a minimum, particularly at a level that does not violate governmental regulations. A unit may be designed so that there is enough power for a triggering a switch at about a cross over point of a waveform of input power to the unit. Power for triggering may come from a storage source rather than line power to reduce emissions on the power line. Power for the storage source may be provided with power stealing. Power stealing may require switching transistors which can generate emissions. Gate signals to the transistors may be especially shaped to keep emissions from transistor switching at a minimum.

A power supply unit for use with thermostats or other like devices requiring power. A power supply unit may be designed to keep electromagnetic interference emissions at a minimum, particularly at a level that does not violate governmental regulations. A unit may be designed so that there is enough power for a triggering a switch at about a cross over point of a waveform of input power to the unit. Power for triggering may come from a storage source rather than line power to reduce emissions on the power line. Power for the storage source may be provided with power stealing. Power stealing may require switching transistors which can generate emissions. Gate signals to the transistors may be especially shaped to keep emissions from transistor switching at a minimum.

The invention discloses a standby control circuit and a display device. The standby control circuit includes a standby module, at least one power board, and a transistor switch control module comprising at least one transistor switch whose number is equal to that of the at least one power board, each transistor switch is connected between one power board and a mains supply input terminal, the standby module is configured to generate a trigger signal and send the generated trigger signal to each transistor switch, and each transistor switch is configured to be turned on upon receipt of the trigger signal sent from the standby module so as to connect the power board connected thereto with the mains supply input terminal.

The present invention discloses an energy-saving electronic touch switch, comprising a touch sensing module, a power supply module and a switch driving module, wherein the touch sensing module is used for receiving a touch sensing signal inputted by a capacitive touch switch, and controlling the action of the switch driving module according to the touch sensing signal, so as to switch on a power supply circuit for the load; and the power supply module feeds power to the touch sensing module. The touch switch can drive various loads and has a wider range of possible loads including inductive, capacitive or purely resistive loads and high-frequency switch power supply loads, such as energy-saving lights, AC (Alternating Current) motors, LEDs (Light Emitting Diodes) new light sources, common fluorescent lamps, and the like. The energy-saving electronic touch switch overcomes the disadvantages of small load range and weak load capacity of conventional switches. The energy-saving electronic touch switch employs chips with low power consumption such as LDO (Low Dropout Regulator) voltage regulator chips, touch chips, and the like, which can reduce the overall power consumption, wherein the overall power consumption is less than 2.2 mW and the single static overall power consumption is less than 10 mW (measured under an indicator lamp). The energy-saving electronic touch switch simplifies circuits and improves the power supply utilization rate.

A bidirectional power switch includes first and second thyristors connected in antiparallel between first and second conduction terminals of the switch. The first thyristor is of an anode-gate thyristor, and the second thyristor is of a cathode-gate thyristor. The gates of the first and second thyristors are coupled to a same control terminal of the switch by respective dipole circuits. At least one of the dipole circuits is formed by at least one diode or at least one resistor.

A bidirectional power switch includes first and second thyristors connected in antiparallel between first and second conduction terminals of the switch. The first thyristor is of an anode-gate thyristor, and the second thyristor is of a cathode-gate thyristor. The gates of the first and second thyristors are coupled to a same control terminal of the switch by respective dipole circuits. At least one of the dipole circuits is formed by at least one diode or at least one resistor.

A system for measuring soft starter current includes a current monitoring system having a controller and a current transfer device that includes a first solid state switching device. A first current sensor is coupled to the first solid state switching device and the controller to sense off-state current of the first solid state switching device. The controller is configured to determine an operational status of the first solid state switching device.