Load control device for high-efficiency loads
First Claim
1. A load control device for controlling power delivered from an AC power source to an electrical load, the load control device comprising:
- a thyristor adapted to be electrically coupled between the AC power source and the electrical load, the thyristor having first and second main terminals through which current can be conducted to energize the electrical load and a gate terminal through which current can be conducted to render the thyristor conductive between the first and second main terminals;
a gate coupling circuit electrically coupled to the gate terminal of the thyristor to conduct current through the gate terminal;
a control circuit configured to control the thyristor to turn the electrical load on and off, the control circuit further configured, when the electrical load is on, to control the gate coupling circuit to conduct a pulse of current through the gate terminal of the thyristor at a first time during a present half-cycle of the AC power source to render the thyristor conductive, and to control the gate coupling circuit to allow the gate coupling circuit to conduct at least one other pulse of current through the gate terminal of the thyristor after the first time during the present half-cycle; and
a power supply configured to conduct current through the electrical load when the thyristor is non-conductive to produce a supply voltage across an energy storage capacitor to power the control circuit;
wherein, when the electrical load is on, the control circuit is configured to prevent the gate coupling circuit from conducting pulses of current through the gate terminal of the thyristor before the first time of the present half-cycle to maintain the thyristor non-conductive until the magnitude of the supply voltage exceeds a predetermined threshold.
1 Assignment
0 Petitions
Accused Products
Abstract
A two-wire load control device (such as, a dimmer switch or an electronic switch) for controlling power delivered from an AC power source to an electrical load includes a thyristor for controlling the power to the load, a gate coupling circuit electrically coupled to a gate terminal of the thyristor, a control circuit configured to control the thyristor to turn the load on or off, and a power supply configured to conduct current through the electrical load to generate a supply voltage across a capacitor when the thyristor is non-conductive. When the electrical lead is on, the control circuit is configured to maintain the thyristor non-conductive after a beginning of each half-cycle until the magnitude of the supply voltage exceeds a predetermined threshold.
71 Citations
27 Claims
-
1. A load control device for controlling power delivered from an AC power source to an electrical load, the load control device comprising:
-
a thyristor adapted to be electrically coupled between the AC power source and the electrical load, the thyristor having first and second main terminals through which current can be conducted to energize the electrical load and a gate terminal through which current can be conducted to render the thyristor conductive between the first and second main terminals; a gate coupling circuit electrically coupled to the gate terminal of the thyristor to conduct current through the gate terminal; a control circuit configured to control the thyristor to turn the electrical load on and off, the control circuit further configured, when the electrical load is on, to control the gate coupling circuit to conduct a pulse of current through the gate terminal of the thyristor at a first time during a present half-cycle of the AC power source to render the thyristor conductive, and to control the gate coupling circuit to allow the gate coupling circuit to conduct at least one other pulse of current through the gate terminal of the thyristor after the first time during the present half-cycle; and a power supply configured to conduct current through the electrical load when the thyristor is non-conductive to produce a supply voltage across an energy storage capacitor to power the control circuit; wherein, when the electrical load is on, the control circuit is configured to prevent the gate coupling circuit from conducting pulses of current through the gate terminal of the thyristor before the first time of the present half-cycle to maintain the thyristor non-conductive until the magnitude of the supply voltage exceeds a predetermined threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A load control device for controlling power delivered from an AC power source to an electrical load, the load control device comprising:
-
a thyristor adapted to be electrically coupled between the AC power source and the electrical load, the thyristor having first and second main terminals through which current can be conducted to energize the electrical load and a gate terminal through which current can be conducted to render the thyristor conductive between the first and second main terminals; a gate coupling circuit electrically coupled to conduct current through the gate terminal of the thyristor; a power supply configured to conduct current through the electrical load to generate a supply voltage across an energy storage capacitor when the thyristor is non-conductive; and a control circuit electrically coupled to the power supply to receive the supply voltage, the control circuit configured to control the thyristor to turn the electrical load on and off, the control circuit configured to prevent the gate coupling circuit from conducting pulses of current through the gate terminal of the thyristor after a beginning of a present half-cycle of the AC power source to maintain the thyristor non-conductive until a magnitude of the supply voltage exceeds a predetermined threshold, the control circuit further configured to subsequently control the gate coupling circuit to conduct a pulse of current through the gate terminal of the thyristor to render the thyristor conductive, and to control the gate coupling circuit to thereafter allow the gate coupling circuit to conduct at least one other pulse of current through the gate terminal of the thyristor before an end of the present half-cycle. - View Dependent Claims (14, 15, 16, 17, 18)
-
-
19. A load control device for controlling power delivered from an AC power source to an electrical load, the load control device comprising:
-
a thyristor adapted to be electrically coupled between the AC power source and the electrical load, the thyristor having first and second main terminals through which current can be conducted to energize the electrical load and a gate terminal through which current can be conducted to render the thyristor conductive between the first and second main terminals; a gate coupling circuit electrically coupled to conduct current through the gate terminal of the thyristor; and a control circuit configured to control the thyristor to turn the electrical load on and off, the control circuit configured, when the electrical load is on, to control the gate coupling circuit to conduct a pulse of current through the gate terminal of the thyristor at a first time during a present half-cycle of the AC power source to render the thyristor conductive, the control circuit configured to control the gate coupling circuit to allow the gate coupling circuit to conduct at least one other pulse of current through the gate terminal of the thyristor between the first time and a second time that occurs before the end of the present half-cycle, the control circuit further configured to prevent the gate coupling circuit from conducting pulses of current through the gate terminal of the thyristor between the second time and an end of the present half-cycle to allow the thyristor to become non-conductive and remain non-conductive until the end of the present half-cycle; and a power supply configured to conduct current through the electrical load to generate a supply voltage across an energy storage capacitor when the thyristor is non-conductive; wherein, when the electrical load is on, the control circuit is configured to prevent the gate coupling circuit from conducting pulses of current through the gate terminal of the thyristor before the first time of the present half-cycle to maintain the thyristor non-conductive to allow the power supply to generate the supply voltage across the energy storage capacitor. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27)
-
Specification