A single-input and single-output touch phase-cut dimming controller includes an AC input terminal, a dimming output terminal, voltage dependent resistors, rectifiers, diodes, Insulated Gate Bipolar Transistors (IGBT), resistors, a sampling circuit, a power supply circuit, a driver circuit, a single-chip microcomputer processor, a touch circuit, an over-current protection circuit, and a brightness regulator. The components on each circuit unit are correspondingly connected to and adapt to each other according to the functional requirements of the circuit design. The controller allows full current to be delivered to the control circuit while lowering overall power consumption and improving convenience and compatibility. The new touch dimmer is not limited to mechanical endurance, and has functions such as soft start, over-current protection and current-limiting protection.

A dimmer includes a power supply circuit including a current limiter and a switch, the power supply circuit electrically coupled to a power source and a load, where current is channeled via the current limiter during a power-on of the dimmer and via the switch during operation of the dimmer after the power-on, a triode for alternating current (TRIAC) control circuit electrically coupled to the power source and the load, where the TRIAC control circuit is structured to control operation of a TRIAC configured to control an amount of power supplied to the load; and a processing unit electrically coupled to the power supply circuit and the TRIAC control circuit, where the processing unit is structured to control the switch and the TRIAC control circuit after the power-on.

A load control device (such as, a dimmer switch) for controlling the amount of power delivered from an AC power source to an electrical load (such as, a high-efficiency lighting load) includes a thyristor (such as, a triac) coupled between the source and the load, a gate coupling circuit arranged to conduct current through a gate terminal of the thyristor, and a control circuit configured to control the gate coupling circuit. The control circuit may control the gate coupling circuit to conduct a pulse of current through the gate terminal to render the thyristor conductive at a firing time during a present half cycle of the AC power source, and allow the gate coupling circuit to conduct at least one other pulse of current after the firing time during the present half cycle.

A load control device for controlling the power delivered from an AC power source to an electrical load includes a thyristor, a gate coupling circuit for conducting a gate current through a gate of the thyristor, and a control circuit for controlling the gate coupling circuit to conduct the gate current through a first current path to render the thyristor conductive at a firing time during a half cycle. The gate coupling circuit is able to conduct the gate current through the first current path again after the firing time, but the gate current is not able to be conducted through the gate from a transition time before the end of the half-cycle until approximately the end of the half-cycle. The load current is able to be conducted through a second current path to the electrical load after the transition time until approximately the end of the half-cycle.

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 circuit adapted to detect applied voltage and/or voltage based conditions. The circuit comprises a zero-cross detection circuit and a controller. The zero-cross detection circuit is adapted to output a zero-cross signal comprising zero-cross events based on an applied alternating current power signal. The controller is adapted to store a relationship between a pulse width delta, frequency, and voltage. The controller is adapted to sense the zero-cross signal from the zero-cross detection circuit to determine its frequency and pulse width delta by calculating a difference between a high-time and a low-time of the zero-cross signal, and determine the applied voltage based on the stored relationship. The controller can adjust at least one setting of the circuit based on the determined applied voltage, such as the timing of a dimming circuit. In another embodiment, the controller may directly detect voltage based conditions, such as zero-cross delays a dimmer circuit. The controller is adapted store a relationship between a pulse width delta and zero-cross signal delay. The controller is adapted to receive the zero-cross signal from the zero-cross detection circuit, determine a pulse width delta, and determine a zero-cross delay based on the determined pulse width delta and the stored relationship.

An electronic device for controlling switching circuitry is described. The electronic device includes line voltage measuring circuitry configured to measure a line voltage to produce a line voltage measurement. The electronic device also includes load voltage measuring circuitry configured to measure a load voltage to produce a load voltage measurement. The electronic device further includes a processor coupled to the line voltage measuring circuitry and the load voltage measuring circuitry. The processor is configured to adjust a control signal for a transition of the switching circuitry based on the line voltage measurement and the load voltage measurement to minimize heat generation and electromagnetic interference creation by the switching circuitry.

A load control device for controlling power delivered from an alternating-current power source to an electrical load may comprise a controllably conductive device, a control circuit, and an overcurrent protection circuit that is configured to be disabled when the controllably conductive device is non-conductive. The control circuit may be configured to control the controllably conductive device to be non-conductive at the beginning of each half-cycle of the AC power source and to render the controllably conductive device conductive at a firing time during each half-cycle (e.g., using a forward phase-control dimming technique). The overcurrent protection circuit may be configured to render the controllably conductive device non-conductive in the event of an overcurrent condition in the controllably conductive device. The overcurrent protection circuit may be disabled when the controllably conductive device is non-conductive and enabled after the firing time when the controllably conductive device is rendered conductive during each half-cycle.

Various embodiments may include a dimmer system for controlling the power consumption of a load that can be connected with parallel-connected galvanically isolated dimming channels. The dimmer system may include a plurality of dimming channels, each dimming channel including a sensor for monitoring a temperature of associated switch elements; and a control unit for each dimming channel, the control units configured to shift a respective dimming edge based at least in part on the temperature to distribute power dissipation of the connected load substantially equally across the plurality of dimming channels.

A dimmer switch system for dimming a load includes a master dimmer structured to be electrically connected to a power source and the load and to control dimming of the load by regulating power provided from the power source to the load, and at least one accessory dimmer structured to be electrically connected to the master dimmer via a traveler conductor. The master dimmer includes a first visual load status indicator structured to emit light in a plurality of colors. The at least one accessory dimmer includes a second visual load status indicator structured to emit light in a plurality of colors, and is structured to set a color of light emitted by the second visual load status indicator based on a first control signal generated by the master dimmer on the traveler conductor, and to generate a second control signal on the traveler conductor.