Multiple output dc voltage regulator

Claim 2

In a system for producing a multiplicity of regulated DC voltages from a source of unregulated DC voltage, the combination comprising: first means for providing a DC reference voltage related to a given one of said regulated voltages; a transformer having a primary winding and a multiplicity of secondary windings; a switch connected in series with said source of unregulated DC voltage and said primary winding; a multiplicity of rectifiers and filters selectively connected to said multiplicity of secondary windings and to said primary winding to produce said regulated DC voltages as said switch is turned on and off, and to clamp the winding connected to the filter producing said given one of said regulated voltages while said switch is off to a level of said regulated voltage produced while said switch was on; means for comparing said given one of said regulated voltages with said DC reference voltage; and control means responsive to said comparing means to turn said switch on when said given one of said regulated voltages falls below said reference voltage, said given one of said regulated voltages being produced by charging current through said primary winding into a filter connected in series with said primary winding at an end opposite said switch, said charging current being furnished while said switch is on, and wherein other filters connected to secondary windings are furnished with inductive current through said secondary windings while said switch is turned off.

Claim 3

The combination of claim 1 wherein said secondary windings are connected in series with said primary winding, each secondary winding having a rectifier and filter at the end remote from said primary winding.

Claim 4

The combination of claim 2 wherein some secondary windings are connected in series with said primary winding at one end thereof for voltages of a given polarity, and some secondary windings are connected in series with said primary winding at the end thereof opposite said one end for voltages of a polarity opposite said given polarity.

Claim 5

The combination of claim 1 wherein said switch comprises a first transistor of a given conductivity type having its collector connected to said source of unregulated voltage, its emitter connected to said primary winding at the end remote from said filter receiving current to produce said given one of said reference voltage, and its base connected to said control means.

Claim 6

The combination of claim 4 wherein said control means comprises: a boost secondary winding of said transformer having one end connected to said source of unreGulated voltage; a boost rectifier and filter connected between said one end of said boost secondary winding and the other end thereof to provide a boost voltage comprising a regulated DC voltage added to said unregulated voltage at the output of said boost rectifier and filter; and a second transistor of a conductivity type complementary to said given conductivity type having its collector connected to the base of said first transistor through a first resistor, its emitter connected to the output of said boost rectifier and filter, and its base connected directly to said comparing means, and a second resistor connecting the base of said second transistor to the output of said boost rectifier and filter, whereby sufficient voltage to saturate said first transistor is provided by said second transistor when said first transistor is turned on.

Claim 7

The combination of claim 5 including a third resistor connected between the base and emitter of said first transistor.

Claim 8

The combination of claim 6 wherein the rectifier connected to said primary winding to produce said given one of said regulated voltages is connected between the emitter of said first transistor and circuit ground to conduct inductive current from said primary winding when said first transistor is turned off.

Claim 9

The combination of claim 7 wherein said multiplicity of secondary windings are connected in series with said primary winding, said secondary windings having associated rectifiers and filters at the ends remote from said primary winding.

Claim 10

The combination of claim 8 wherein some secondary windings are connected in series with said primary winding at one end thereof for voltages of a given polarity, and some secondary windings are connected in series with said primary winding at the end thereof opposite said one end for voltages of a polarity opposite said given polarity.

Claim 11

The combination of claim 1 wherein said switch comprises a transistor having its collector connected to said source of unregulated voltage through said primary winding, its emitter connected to said given one of said regulated voltages, and its base connected to said control means.

Claim 12

The combination of claim 10 wherein said control means comprises a push-pull amplifier for driving the base of said transistor above said given one of said reference voltages sufficiently to drive said transistor into saturation when said given one of said regulated voltages falls below said reference voltage.

Claim 13

In a system for producing a multiplicity of regulated DC voltages from a source of unregulated DC voltage of a given polarity, the combination comprising: a DC reference voltage of said given polarity related to a given one of said regulated voltages; a transformer having a primary winding and a multiplicity of secondary windings, said primary and secondary windings being connected in series; a multiplicity of filters, one for each of said windings, each having a first terminal connected to circuit ground and a second terminal, and a particular filter having its second terminal connected to one end of said primary winding; a multiplicity of rectifiers, one rectifier for each of said secondary windings connected between one end thereof and a second terminal of a different one of said filters except said particular one, and a particular rectifier connected between circuit ground and an end of said primary winding opposite said one end to which said particular filter is connected, said particular diode being poled to be back biased by voltage of said given polarity; means for comparing said reference voltage with voltage across said particular filter to produce a drive signal when said voltage across said filter is less than said reference voltage; and a switch having input and output terminals connected in series between said source of unregulated DC voltage and said end of said primary winding opposite said one end to which said particular filter is connected, and having a contRol terminal adapted to receive said drive signal to turn said switch on in response thereto whereby driving current is provided to said particular filter when said switch is on, and said primary winding is clamped to voltage across said particular filter when said switch is turned off to produce all of said regulated voltages, each regulated voltage being related to said clamping voltage by a turn''s ratio of one of said secondary windings associated therewith to said primary winding.

Claim 14

In a system for producing a multiplicity of regulated DC voltages from a source of unregulated DC voltage of a given polarity, the combination comprising: a DC reference voltage of said given polarity related to a given one of said regulated voltages; a transformer having a primary winding and a multiplicity of secondary windings, said primary and secondary windings being connected in series; a multiplicity of filters, one for each of said windings, each having a first terminal connected to circuit ground and a second terminal, and a particular filter having its second terminal connected to one end of said primary winding; a multiplicity of rectifiers, one rectifier for each of said secondary windings connected between one end thereof and a second terminal of a different one of said filters except said particular one, and a particular rectifier connected between circuit ground and an end of said primary winding opposite said one end to which said particular filter is connected, said particular diode being poled to be back biased by voltage of said given polarity; means for comparing said reference voltage with voltage across said particular filter to produce a drive signal when said voltage across said filter is less than said reference voltage; and a switch having input and output terminals connected in series between said source of unregulated DC voltage and said end of said primary winding opposite said one end to which said particular filter is connected, and having a contRol terminal adapted to receive said drive signal to turn said switch on in response thereto whereby driving current is provided to said particular filter when said switch is on, and said primary winding is clamped to voltage across said particular filter when said switch is turned off to produce all of said regulated voltages, each regulated voltage being related to said clamping voltage by a turn''s ratio of one of said secondary windings associated therewith to said primary winding.

Claim 15

The combination of claim 12 wherein said switch comprises a first transistor of a given conductivity type having its collector connected to said source of unregulated voltage, its emitter connected to said primary winding at an end thereof remote from said particular filter, and its base adapted to receive said drive signal.

Claim 16

The combination of claim 13 wherein said base of said first transistor is adapted to receive said drive signal by a boost voltage system comprising: a boost secondary winding of said transformer having one end connected to said source of unregulated voltage; a boost rectifier and filter connected between said one end of said boost secondary winding and the other end thereof to provide a boost voltage comprising a regulated DC voltage added to said unregulated voltage at the output of said boost rectifier and filter; and a second transistor of a conductivity type complementary to said given conductivity type having its collector connected to the base of said first transistor through a first resistor, its emitter connected to the output of said boost rectifier and filter, and its base connected directly to said comparing means, and a second resistor connecting the base of said second transistor to the output of said boost rectifier and filter, whereby sufficient voltage to saturate said first transistor is provided by said second transistor when said first transistor is turned on by said drive signal from said comparing means.

Claim 17

The combination of claim 14 including a third resistor connected between the base and emitter of said first transistor.

Claim 18

The combination of claim 15 wherein some secondary windings are connected in series with said primary winding at one end thereof for voltages of a given polarity, and some secondary windings are connected in series with said primary winding at the end thereof opposite said one end for voltages of a polarity opposite said given polarity.

Claim 19

In a system for producing a multiplicity of regulated DC voltages from a source of unregulated DC voltage of a given polarity, the combination comprising: a DC reference voltage of said given polarity related to a given one of said regulated voltages; a transformer having a primary winding and a multiplicity of secondary windings; a multiplicity of rectifiers and filters selectively connected to said multiplicity of secondary windings and to said primary winding to produce said regulated DC voltages; a transistor having a collector in series with said source of unregulated voltage and said primary winding, and an emitter connected to one of said filters adapted to produce said given one of said regulated voltages, and a base adapted to receive a drive signal; and means for comparing said given one of said regulated voltages with said DC reference voltage and producing said drive signal to turn said transistor on while said given one of said regulated voltages is below said reference voltage, whereby the secondary winding connected to the rectifier and filter provided for producing said given one of said regulated voltages is clamped, while said transistor is turned off, to the voltage to which driven while said transistor was last turned on to produce all of said regulated voltages, each regulated voltage being related to said clamping voltage by a turn''s ratio of one of said secondary windings associated therewith to said primary winding.

Claim 20

In a system for producing a multiplicity of regulated DC voltages from a source of unregulated DC voltage of a given polarity, the combination comprising: a DC reference voltage of said given polarity related to a given one of said regulated voltages; a transformer having a primary winding and a multiplicity of secondary windings; a multiplicity of rectifiers and filters selectively connected to said multiplicity of secondary windings and to said primary winding to produce said regulated DC voltages; a transistor having a collector in series with said source of unregulated voltage and said primary winding, and an emitter connected to one of said filters adapted to produce said given one of said regulated voltages, and a base adapted to receive a drive signal; and means for comparing said given one of said regulated voltages with said DC reference voltage and producing said drive signal to turn said transistor on while said given one of said regulated voltages is below said reference voltage, whereby the secondary winding connected to the rectifier and filter provided for producing said given one of said regulated voltages is clamped, while said transistor is turned off, to the voltage to which driven while said transistor was last turned on to produce all of said regulated voltages, each regulated voltage being related to said clamping voltage by a turn''s ratio of one of said secondary windings associated therewith to said primary winding.

Claim 21

The combination of claim 17 wherein said means for comparing And producing said drive signal comprises a voltage comparator and a push-pull amplifier connected in cascade, with the push-pull output of said amplifier connected to the base of said transistor.