Electrical dimmer system employing alternately applied silicon controlled rectifiers
First Claim
1. A dimmer control system comprising, in combination:
- first and second conductors spaced apart from each other and respectively connected to the positive and negative terminals of an AC voltage source;
a first silicon controlled rectifier discrete current switching device and a second silicon controlled rectifier discrete current switching device, each of said switching devices connect between said fist and second conductors such that said first discrete current switching device conducts current to a load during a portion of the half cycles when positive AC voltage is applied to said first conductor and said second discrete current switching device conductors current to said load during a portion of the half cycles where positive AC voltage is applied to said second conductor;
first and second gate energization circuits respectively, connected to said first and second silicon controlled rectifiers;
said first gate energization circuit comprises a first capacitor and a first diac connected in series with the gate terminal of said first silicon controlled rectifier and said second gate energization circuit comprises a second capacitor and a second diac connected in series with the gate terminal of said second silicon controlled rectifier.
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Accused Products
Abstract
A dimmer control system includes two discrete silicon controlled rectifiers which respectively energize a lamp load during alternate half cycles of the input AC voltage. The separate placement of the SCRs ensures that much lower temperatures are reached than would occur if a single triac were used to energize a lamp during both half cycles. The system also includes a pair of diacs which energize the respective SCRs when a respective capacitor directly connected to each diac discharges through one of them. The system further includes a respective capacitor charging circuit for each capacitor, each of the two charge circuits including a series connections of the gate to cathode junction of the SCR other than the one which the capacitor being charged discharges through, a diode, a common fixed resistor, and a common variable resistor.
23 Citations
8 Claims
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1. A dimmer control system comprising, in combination:
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first and second conductors spaced apart from each other and respectively connected to the positive and negative terminals of an AC voltage source; a first silicon controlled rectifier discrete current switching device and a second silicon controlled rectifier discrete current switching device, each of said switching devices connect between said fist and second conductors such that said first discrete current switching device conducts current to a load during a portion of the half cycles when positive AC voltage is applied to said first conductor and said second discrete current switching device conductors current to said load during a portion of the half cycles where positive AC voltage is applied to said second conductor; first and second gate energization circuits respectively, connected to said first and second silicon controlled rectifiers;
said first gate energization circuit comprises a first capacitor and a first diac connected in series with the gate terminal of said first silicon controlled rectifier and said second gate energization circuit comprises a second capacitor and a second diac connected in series with the gate terminal of said second silicon controlled rectifier. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification