588 results about "TRIAC" patented technology

Exemplary embodiments provide an impedance matching circuit for providing variable power from a dimmer switch having a triac to a switching power supply couplable to solid-state lighting. An exemplary impedance matching circuit includes a first resistor coupled to receive a first current from the switching power supply; a second resistor; and a transistor coupled in series to the second resistor, with the transistor responsive to a gate voltage to modulate a second current through the second resistor in response to a detected level of the first current through the first resistor.

An exemplary embodiment provides a current regulator for controlling variable brightness levels for solid state lighting. The current regulator is couplable to a phase-modulating switch, such as a dimmer switch, which is coupled to an AC line voltage. An exemplary current regulator includes a rectifier; a switching power supply providing a first current; an impedance matching circuit; and a controller. The impedance matching circuit is adapted to provide a second current through the phase-modulating switch when a magnitude of the first current is below a first predetermined threshold, such as a holding current of a triac of the phase-modulating switch. The controller is adapted to determine a root-mean-square (RMS) voltage level provided by the phase-modulating switch from the AC line voltage and to determine a duty cycle for pulse-width current modulation by the switching power supply in response to the comparison of the RMS voltage level to a nominal voltage level.

The invention disclosed herein is a dynamic dummy load to allow a phase control dimmer to be used with LED lighting. The invention includes providing a dynamic dummy load to provide a load to the dimmer when the LED electronics do not provide sufficient load due to start up issues or ringing in the circuit, the dynamic dummy load providing a reduced flow of current when the LED and its converter electronics provide sufficient current draw from the dimmer. The system generally includes a power source electrically connected to a phase control dimmer, the phase control dimmer electrically connected to converter circuitry to convert the AC power output of the dimmer to DC power output for powering the LED lighting, a dynamic dummy load electrically connected in parallel with the converter circuitry, the dummy load varying its current draw in response to operation of the converter circuitry.

A smart dimmer for control of a lighting load from an AC power source can replace any switch in a three-way or four-way lighting control system. The smart dimmer can be connected on the line-side or the load-side of a three-way system with a standard three-way switch in the other location. According to one embodiment of the present invention, the dimmer includes two triacs to control the intensity of the connected lighting load. The dimmer preferably includes two gate drive circuits coupled to the gates of the triacs for rendering the triacs conductive each half-cycle of the AC power source. The gate drive circuits include sensing circuits for detect whether the gates currents are flowing after the triacs are rendered conductive. A controller is operable to determine the state of the lighting load in response to whether the gate current is flowing or not flowing.

A central vacuum cleaning system control subsystem for use in a central vacuum cleaning system having a motor includes a central vacuum unit control module with a receiver for wirelessly receiving command signals, and a power stage for controlling the motor in accordance with command signals received through the receiver. The control module is stable in high ambient temperature. Current flowing to the motor is sensed, and motor overcurrent and undercurrent conditions are determined. The control module determines when the motor is in an overcurrent condition. Power stage has a triac for controlling power to the motor. The control module also has a microprocessor that compares the current sensed against a normal operating current to determine overcurrent condition. Power to motor ceases when overcurrent condition exists. A generator is powered by air flow in a cleaning system for production of electrical energy.