Protective circuit is provided for wiring accessory including switch circuit and switch controller. Switch circuit possesses control terminal, and is electrically connected between input terminals that allow electrical connection to both ends of series circuit of AC power grid and load, and is switched between conductive and non-conductive between both ends of series circuit according to control signal to control terminal. Protective circuit includes current sensor that detects electric current flowing through switch circuit, and protective switch that is electrically connected between control terminal and potential reference point, and turns on when current value of electric current detected through current sensor exceeds threshold value.

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 coupled to conduct current through a gate terminal of the thyristor, a controllable switching circuit coupled between the gate coupling circuit and the gate terminal of the thyristor, and a control circuit configured to control the gate coupling circuit and the controllable switching circuit. The control circuit may cause 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.

The present invention provides an LED lamp and a temperature control circuit applied to the LED lamp. The LED lamp includes at least one LED unit, a magnetic ballast, and an LED drive circuit. The magnetic ballast is coupled to a power and configured to limit and stabilize a received alternating current. The LED drive circuit includes a temperature control circuit. The temperature control circuit is coupled to the magnetic ballast and connected in parallel with the LED unit, is configured to detect an internal temperature of the LED lamp and adjust an output power of the LED unit, and includes a thermal sensitive module having a negative temperature coefficient thermistor and a phase cut circuit. The phase cut circuit is coupled to the thermal sensitive module, and adjusts the output power of the LED unit by decreasing a resistance of the negative temperature coefficient thermistor when the negative temperature coefficient thermistor detects that the internal temperature of the LED lamp is higher than a specified temperature threshold.

A two-wire 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 coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

A control unit controls a bidirectional switch so as to turn the switch from ON to OFF when an amount of time, varying according to a lighting level, passes since a starting point of a half cycle of an AC voltage. When a voltage between both terminals of a capacitive element, connected to a control terminal of the bidirectional switch, becomes equal to or greater than a threshold voltage, the bidirectional switch turns from OFF to ON A first charging/discharging regulator circuit and a second charging/discharging regulator circuit each make a rate of fall of the voltage between both of the terminals of the capacitive element when the bidirectional switch turns from ON to OFF lower than a rate of rise of the voltage between both of the terminals of the capacitive element when the bidirectional switch turns from OFF to ON.

A multiple location dimming system may include a smart dimmer (e.g., a main load control device) and one or more remote dimmers (e.g., accessory devices) for controlling the amount of power delivered to a lighting load. The multiple location dimming system may be installed in place of a multiple location switch system (e.g., having three, four, or more multi-way switches), and may not require a neutral connection at any of the control devices of the multiple location dimming system. The main load control device and the accessory devices of the multiple location dimming system may be configured to display a present intensity level of a lighting load on one or more visual indicators. The accessory devices may have the same or different user interfaces as the main load control device, and may provide additional functionality over that which the main load control device offers.

A two-wire 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 coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

A two-wire 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 coupled between the source and the load, a gate coupling circuit coupled between a first main load terminal and the gate of the thyristor, and a control circuit coupled to a control input of the gate coupling circuit. The control circuit generates a drive voltage for causing the gate coupling circuit to conduct a gate current to thus render the thyristor conductive at a firing time during a half cycle of the AC power source, and to allow the gate coupling circuit to conduct the gate current at any time from the firing time through approximately the remainder of the half cycle, where the gate coupling circuit conducts approximately no net average current to render and maintain the thyristor conductive.

System and method for controlling one or more light emitting diodes. For example, the system includes a bleeder configured to receive a rectified voltage generated by a rectifying bridge, and a dimmer detector configured to receive an input voltage generated by a voltage divider, determine whether or not the rectified voltage is associated with a TRIAC dimmer, and output a control signal to the bleeder. The voltage divider is configured to receive the rectified voltage, and the input voltage indicates a magnitude of the rectified voltage.

The present invention refers to an Electrical Power System (EPS) or Power Supply for a smart dimmer for controlling the intensity of illumination of a dimmable lighting load within an electrical installation that has two or three wires in the switch box (two-wire and three-wire switches). The Power Supply is able to detect and control different types of lighting technologies, such as incandescent or LED bulbs. The Power Supply also provides a voltage signal indicating the current consumed by the lighting loads.