Zero-crossover SCR power supply regulator
First Claim
1. A regulator circuit for a power supply including a silicon-controlled rectifier for developing a substantially constant transient-free DC voltate from an applied AC voltage source, comprising:
- zero-crossover circuit means responsive to cyclical variations of said AC voltage source for providing a signal indicative of the zero-crossing of one phase of said applied AC voltage source,switching means responsive to said zero-crossing signal and coupled to initiate conduction of said silicon-controlled rectifier substantially coincident with said zero-crossing of said applied AC voltage source,control logic means responsive to a DC reference potential representative of said developed DC voltage and coupled to provide an output signal to said switching means for suppressing said zero-crossing signal and thereby inhibiting conduction of said silicon-controlled rectifier when said developed DC voltage exceeds a predetermined potential and for triggering conduction of said silicon-controlled rectifier when said developed DC voltage has a value less than said predetermined potential,said zero-crossover circuit means further comprising;
(1) means responsive to a transition from a first polarity of said applied AC voltage source to an opposing polarity for providing a current corresponding to at least a portion of said applied AC voltage source,(2) means responsive to said current corresponding to said AC voltage source for providing a pulsed signal of a predetermined polarity,(3) means for providing a first reference bias potential,(4) logic circuit means responsive to a predetermined algebraic difference of said pulsed signal and said reference bias potential for providing an output signal synchronous with said AC voltage source,(5) differentiating circuit means responsive to said synchronous signal for providing a differentiated output signal to further logic circuit means, and(6) means for providing a second reference bias potential,said further logic circuit means responsive to a predetermined algebraic difference of said differentiated output signal and said second reference bias potential for producing a logic signal output indicative of said zero-crossing of said one phase of said applied AC voltage source.
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Accused Products
Abstract
A circuit for regulating the output of a DC power supply that substantially eliminates turn-on transients induced by the switching of a silicon-controlled rectifier (SCR). A zero-crossover detector senses the AC voltage waveform of an applied power source and provides a trigger signal at the zero-crossing point. The trigger signal is applied to cause induction of the SCR'"'"'s and raise the output voltage when the power supply output drops below a regulated value, and is interrupted so as to inhibit conduction of the SCR'"'"'s and decrease the output voltage when the power supply output exceeds the regulated value.
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Citations
11 Claims
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1. A regulator circuit for a power supply including a silicon-controlled rectifier for developing a substantially constant transient-free DC voltate from an applied AC voltage source, comprising:
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zero-crossover circuit means responsive to cyclical variations of said AC voltage source for providing a signal indicative of the zero-crossing of one phase of said applied AC voltage source, switching means responsive to said zero-crossing signal and coupled to initiate conduction of said silicon-controlled rectifier substantially coincident with said zero-crossing of said applied AC voltage source, control logic means responsive to a DC reference potential representative of said developed DC voltage and coupled to provide an output signal to said switching means for suppressing said zero-crossing signal and thereby inhibiting conduction of said silicon-controlled rectifier when said developed DC voltage exceeds a predetermined potential and for triggering conduction of said silicon-controlled rectifier when said developed DC voltage has a value less than said predetermined potential, said zero-crossover circuit means further comprising; (1) means responsive to a transition from a first polarity of said applied AC voltage source to an opposing polarity for providing a current corresponding to at least a portion of said applied AC voltage source, (2) means responsive to said current corresponding to said AC voltage source for providing a pulsed signal of a predetermined polarity, (3) means for providing a first reference bias potential, (4) logic circuit means responsive to a predetermined algebraic difference of said pulsed signal and said reference bias potential for providing an output signal synchronous with said AC voltage source, (5) differentiating circuit means responsive to said synchronous signal for providing a differentiated output signal to further logic circuit means, and (6) means for providing a second reference bias potential, said further logic circuit means responsive to a predetermined algebraic difference of said differentiated output signal and said second reference bias potential for producing a logic signal output indicative of said zero-crossing of said one phase of said applied AC voltage source. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A zero-crossover control circuit for a polyphase power supply providing a regulated DC output voltage, comprising:
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means responsive to a transition from a first polarity of an applied AC voltage source to an opposing polarity for providing a current corresponding to at least a portion of said applied AC voltage source, means responsive to said current corresponding to said AC voltage source for providing a pulsed signal of a predetermined polarity, means for providing a first reference bias potential, logic circuit means responsive to a predetermined algebraic difference of said pulsed signal and said reference bias potential for providing an output signal synchronous with said AC voltage source, differentiating circuit means responsive to said synchronous output signal for providing a differentiated output signal to further logic circuit means, and means for providing a second reference bias potential, said further logic circuit means responsive to a predetermined algebraic difference of said differentiated output signal and said second reference bias potential for producing a logic signal output indicative of said zero-crossing of said one phase of said applied AC voltage source.
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Specification