摘要:
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.
摘要:
A two-wire load control device (such as, a dimmer switch) for controlling 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 first circuit coupled between a first main terminal and a gate terminal of the thyristor to conduct current through the gate terminal, a second circuit coupled between the first main terminal and a second main terminal of the thyristor to conduct current through the load when the thyristor is non-conductive, and a control circuit configured to individually control the first and second circuits. The control circuit renders the first circuit conductive to conduct a pulse of current through the gate terminal to render the thyristor conductive at a firing time, and allows the first circuit to conduct at least one other pulse of current through the gate terminal after the firing time.
摘要:
A load control device, such as an LED dimmer switch, for example, may be configured to automatically determine whether to provide a forward or reverse phase control signal to a load. As disclosed herein, such a load control device may provide a plurality of different control signals to the lighting load, for example, during an initial set-up procedure. The load control device may provide the plurality of different control signals to determine an appropriate control signal for the load. Each control signal may be characterized by a load control type and a switching time. The load control type may be one of a forward phase control type, a reverse phase control type, or a full conduction control type. The switching time may include, but is not limited to, switching times of approximately 0 μs, 10 μs, 50 μs, and 100 μs.
摘要:
A load control device may control the amount of power provided to an electrical load utilizing a phase control signal that operates in a reverse phase control mode, a center phase control mode, and a forward phase control mode. A load control device may be configured to determine that the electrical load should be operated via a phase control signal operating in a forward phase-control mode. After determining to operate the electrical load via the phase control signal in the forward phase-control mode, the load control device may provide the phase control signal in a reverse phase-control mode for a predetermined period of time to the electrical load, for example, to charge a bus capacitor of the electrical load. Subsequently, the load control device may be configured to switch the phase control signal to the forward phase-control mode and provide the phase control signal in the forward phase-control mode to the electrical load.
摘要:
A load control device for controlling power delivered from an AC power source to an electrical load includes a thyristor, a first current path for conducting current through a gate terminal of the thyristor, and a control circuit for controlling the first current path to conduct a pulse of current through the gate terminal to render the thyristor conductive at a firing time during a present half cycle. The first current path is able to conduct at least one other pulse of current through the gate terminal between the firing time, and a second time that occurs before an end of the present half-cycle, but is prevented from conducting pulses of current between the second time and the end of the present half-cycle. The load control device includes a second current path for conducting current through the electrical load if the thyristor becomes and remains non-conductive during the present half-cycle.
摘要:
A load control device may control the amount of power provided to an electrical load utilizing a phase control signal that operates in a reverse phase control mode, a center phase control mode, and a forward phase control mode. A load control device may be configured to determine that the electrical load should be operated via a phase control signal operating in a forward phase-control mode. After determining to operate the electrical load via the phase control signal in the forward phase-control mode, the load control device may provide the phase control signal in a reverse phase-control mode for a predetermined period of time to the electrical load, for example, to charge a bus capacitor of the electrical load. Subsequently, the load control device may be configured to switch the phase control signal to the forward phase-control mode and provide the phase control signal in the forward phase-control mode to the electrical load.
摘要:
A load control device for controlling the power delivered from an AC power source to an electrical load includes a thyristor, a first current path for conducting current through a gate terminal of the thyristor, and a control circuit for controlling the first current path to conduct a pulse of current through the gate terminal to render the thyristor conductive at a firing time during a half cycle. The first current path is able to conduct at least one other pulse of current through the gate terminal again after the firing time until, a transition time before the end of the half-cycle, but prevented from conducting pulses of current after the transition time until the end of the half-cycle. The load control device may comprise a second current path for conducting current through the electrical load between the transition time and the end of the half-cycle.
摘要:
A load control device, such as an LED dimmer switch, for example, may be configured to automatically determine whether to provide a forward or reverse phase control signal to a load. As disclosed herein, such a load control device may provide a plurality of different control signals to the lighting load, for example, during an initial set-up procedure. The load control device may provide the plurality of different control signals to determine an appropriate control signal for the load. Each control signal may be characterized by a load control type and a switching time. The load control type may be one of a forward phase control type, a reverse phase control type, or a full conduction control type. The switching time may include, but is not limited to, switching times of approximately 0 μs, 10 μs, 50 μs, and 100 μs.
摘要:
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.
摘要:
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.