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US 4,073,003 AGranted
High efficiency low-loss power supply
AssigneeRaytheon Company
InventorDerek Chambers
Life of this patent
Estimating the term…
Abstract
A synchronized power supply for use with display systems and data processing equipment in general in which information is displayed on a screen such as a cathode ray tube in which the power supply is synchronized to the display such that internal synchronization is maintained regardless of variation in external synchronization. A unique converter arrangement transfers regulated power to the loads at high efficiency such that both improved power supply and display operation result.
Claims17
In combination:
- a transformer, said transformer having a primary winding and first and second secondary windings;
- a single transistor switching element;
- means for a DC current to said switching element through said primary winding;
- and
- means for turning said switching element ON and OFF at a predetermined rate, said turning said switching element ON and OFF occurring only when the voltage across said switching element is substantially zero, a high voltage being produced across a load coupled to said first secondary winding when said switching element is OFF and a low voltage being produced across a load coupled to said second secondary winding when said switching element is ON, all input current for producing said high voltage and low voltage flowing through said single transistor switching element.
2 more elements
A DC-to-DC converter comprising:
- a transformer, said transformer having a primary winding and first and second secondary windings;
- a single transistor switching element;
- means for supplying DC current to said switching element through said primary winding;
- and
- means for turning said switching element ON and OFF at a predetermined rate such that said DC current is converted to an asymmetric waveform and switched across said primary winding at a predetermined rate, a high voltage being produced across a load coupled to said first secondary winding when said switching element is OFF and a low voltage being produced across a load coupled to said second secondary winding when said switching element is ON, all input current for producing said high voltage and said low voltage flowing through said single transistor switching element.
2 more elements
A pulse width modulated switching power supply comprising:
- a transformer, said transformer having a primary winding and first and second secondary windings;
- regulator means for switching an input DC current from a DC voltage source to produce an asymmetric waveform, across said primary winding, said switching occurring in response to a synchronization signal, and said switching occurring only when the voltage across a single transistor switching element is substantially zero all input current to said regulator means flowing through said single transistor switching element;
- synchronized oscillator means for deriving said synchronization signal from an external source such that said synchronized oscillator means is synchronized to said external source within predetermined limits of frequency variation of said external source and for generating internal synchronization when said external synchronization frequency exceeds said predetermined limits;
- and
- transformer means for coupling said asymmetric waveform to first and second loads coupled to said first and second secondary windings, a high voltage being produced across said first load when said switching element is OFF and a low voltage being produced across said second load when said switching element is ON.
2 more elements
A synchronization circuit comprising:
- means capable of being triggered in response to an external pulse applied to a first input of said means, said means comprising a one-shot multivibrator having a predetermined reset time duration;
- means coupled to a second input of said first mentioned means for triggering said first mentioned means when said external pulse does not occur within a predetermined time duration;
- and
- means for switching power in response to said first mentioned means, said switching means comprising a transistor, switching occurring only when the voltage across said transistor is substantially zero, a high voltage being produced when said switching means is OFF and a low voltage being produced when said switching means is ON, all input current for producing said high voltage and said low voltage flowing through said single transistor switching element.
1 more element
In combination:
- means for converting an AC voltage to a first DC voltage;
- means for converting said first DC voltage to a second DC voltage;
- means for generating a third DC voltage at a higher voltage than either said first or second DC voltages;
- means for synchronizing said first, second, and third DC voltages such that all of said DC voltages are synchronized to each other and to a cyclic characteristic of an external system;
- and
- means for maintaining synchronization between said first, second, and third DC voltages when said cyclic characteristic varies beyond predetermined limits.
3 more elements
In combination:
- a transformer, said transformer having a primary winding and first and second secondary windings;
- a single transistor switching element coupled to said primary winding;
- digital control means for turning said switching element ON and OFF at a predetermined rate, said turning said switching element ON and OFF occurring only when the voltage across said switching element is substantially zero, a high voltage being produced across a load coupled to said first secondary winding when said switching element is OFF and a low voltage being produced across a load coupled to said second secondary winding when said switching element is ON, all input current for producing said high voltage and said low voltage flowing through said single transistor switching element and said primary winding.
Dependencies are inferred from the claim text.