Power efficient line synchronized dimmer
First Claim
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1. A dimmer circuit comprising:
- a latchable switch having an unlatched OFF state below a holding current level for controlling delivery of power of an AC power source to a load, the dimmer circuit having an input line voltage terminal and a load terminal, the load terminal coupled to the input line voltage terminal by the latchable switch;
wherein the dimmer circuit is operative for detecting a first voltage across the input line voltage terminal and the load terminal;
wherein based on the first voltage the dimmer circuit is operative to fire the latchable switch at a time that is within a fourth quadrant of a half cycle of an input line voltage; and
wherein when current passing from the input line voltage terminal to the load terminal falls below the holding current level, the latchable switch enters an unlatched OFF state.
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Accused Products
Abstract
There is set forth herein a dimmer circuit for controlling delivery of input line voltage to a load. The dimmer circuit can include a switch coupling an input line voltage terminal to a load terminal. The dimmer circuit can be operative to provide one or more switch firing control scheme for latching the switch.
175 Citations
17 Claims
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1. A dimmer circuit comprising:
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a latchable switch having an unlatched OFF state below a holding current level for controlling delivery of power of an AC power source to a load, the dimmer circuit having an input line voltage terminal and a load terminal, the load terminal coupled to the input line voltage terminal by the latchable switch; wherein the dimmer circuit is operative for detecting a first voltage across the input line voltage terminal and the load terminal; wherein based on the first voltage the dimmer circuit is operative to fire the latchable switch at a time that is within a fourth quadrant of a half cycle of an input line voltage; and wherein when current passing from the input line voltage terminal to the load terminal falls below the holding current level, the latchable switch enters an unlatched OFF state. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A dimmer circuit comprising:
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a latchable switch having an unlatched OFF state below a holding current level for controlling delivery of power of an AC power source to a load, the dimmer circuit having an input line voltage terminal and a load terminal, the load terminal coupled to the input line voltage terminal by the latchable switch; wherein the dimmer circuit is operative, during a conducting phase of the latchable switch, to monitor a first voltage across the input line voltage terminal and the load terminal to detect a change in state of the latchable switch from an ON state to an unlatched OFF state when current passing from the input line voltage terminal to the load terminal falls below the holding current level; and wherein based on the change in state being detected, the dimmer circuit is operative to cause the latchable switch to return to an ON state. - View Dependent Claims (9, 10, 11, 12)
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13. A dimmer circuit comprising:
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a latchable switch having an unlatched OFF state below a holding current level for controlling delivery of power of an AC power source to a load, the dimmer circuit having an input line voltage terminal and a load terminal, the load terminal coupled to the input line voltage by the latchable switch; wherein when current passing from the input line voltage terminal to the load terminal falls below the holding current level, the latchable switch in an unlatched OFF state enters a non conducting phase; wherein the dimmer circuit within a non conducting phase of the dimmer circuit occurring during a positive half cycle of an input line voltage is operative for detecting a first voltage across the input line voltage terminal and the load terminal; wherein the dimmer circuit within a non conducting phase of the dimmer circuit occurring during a negative half cycle of the input line voltage is operative for detecting a second voltage across the input line voltage terminal and the load terminal; wherein during the positive half cycle of the input line voltage the dimmer circuit is operative to fire the latchable switch based on the detecting a first voltage; and wherein during the negative half cycle of the input line voltage the dimmer circuit is operative to fire the latchable switch based on the detecting a second voltage. - View Dependent Claims (14, 15, 16, 17)
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Specification