US3600667A - Power supply having parallel dissipative and switching regulators - Google Patents

Power supply having parallel dissipative and switching regulators Download PDF

Info

Publication number
US3600667A
US3600667A US858399A US3600667DA US3600667A US 3600667 A US3600667 A US 3600667A US 858399 A US858399 A US 858399A US 3600667D A US3600667D A US 3600667DA US 3600667 A US3600667 A US 3600667A
Authority
US
United States
Prior art keywords
load
terminal
transistor
dissipative
emitter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US858399A
Inventor
William D Wynn
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
United States Department of the Army
Original Assignee
United States Department of the Army
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by United States Department of the Army filed Critical United States Department of the Army
Application granted granted Critical
Publication of US3600667A publication Critical patent/US3600667A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05FSYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
    • G05F1/00Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
    • G05F1/10Regulating voltage or current 
    • G05F1/46Regulating voltage or current  wherein the variable actually regulated by the final control device is DC
    • G05F1/56Regulating voltage or current  wherein the variable actually regulated by the final control device is DC using semiconductor devices in series with the load as final control devices
    • G05F1/563Regulating voltage or current  wherein the variable actually regulated by the final control device is DC using semiconductor devices in series with the load as final control devices including two stages of regulation at least one of which is output level responsive, e.g. coarse and fine regulation

Definitions

  • ABSTRACT The parallel combination of a dissipative-type [50] Field of Search 323/4, 9, regulator and a switching-type regulator is controlled by a dif- 7 16-25; 307/242, 297 ferential amplifier to provide steady state power to a load.
  • a This invention relates to a low voltage-high current regulated power supply having high efficiency and a fast response time. To achieve the desired parameters, advantages is taken of the advantages of both the series or dissipative-type of regu later and theswitching-type of regulator.
  • the series or dissipative-type of regulator offers a fast response time at the sacrifice of efficiency while the switching-type of regulator offers high efficiency at the sacrifice of response time.
  • both types are used simultaneously with the outputs paralleled.
  • Both regulators are chosen to be capable of supplying the entire load alone.
  • the switching-type of regulator is connected as a slave to the dissipative regulator. When the current through the dissipative regulator exceeds a predetermined low level, the output from the switching regulator will increase until it is supplying the major portion of the load current.
  • the dissipative regulator supplies current at a fast response time. The switching regulator then assumes the load current, supplying it more efficiently than does the dissipative regulator.
  • Voltage reference circuit 8 may be any device for establishing a voltage reference, Le, a zener diode.
  • a small resistor R1 is placed in series with the output of transistor QI. Any increase or decrease in the voltage across R1 is sensed by amplifier A2 through resistor R2.
  • Resistors R1, R2, and R3 comprise a voltage divider which, under steady state conditions, establishes a zero differential input voltage at the input of A2. During this steady state condition the current through R1 would be equal to that predetermined keep alive" current supplied through Q1.
  • T1 and Q4 may be considered as a blocking oscillator, but with one important difference. That difference is that the core in T1 has a very square-type hysteresis loop, preferably with a Br to Bm ratio of approximately 90 percent.
  • Winding D of transformer T1 is a reset winding. Circuit action is initiated by a pulse from pulse generator 6, any state of the art device for delivering a pulse having a predetermined pulse repetition rate. This pulse causes O4 to saturate. With Q4 saturated, the input DC voltage causes current to flow through winding A of transformer T1 to provide outputs from windings B and C of transformer T1. The output from winding B locks Q4 in saturation.
  • the output from winding C of T1 causes power switch Q3 to saturate and deliver power to-the LC filter composed of inductor L1 and capacitor C1.
  • Q4 conducts until T1 saturates.
  • the outputs from windings B and C of T1 reduce to zero and Q3 and Q4 cease to conduct, thus ending the power pulse.
  • the resultant rise in collector voltage on Q4 will cause O5 to saturate and begin a reset cycle for T1.
  • the extent to which the core is reset is determined by the time between the end of a power pulse and the beginning of the next power pulse and the DC level supplied by A2.
  • the DC level supplied by amplifier A2 is in turn controlled by the current through R1.
  • An increase or decrease in the output load current from the predetermined steady state value will cause a change in voltage at the input of A2.
  • This voltage at the input of A2 will cause the output of A2 to increase or decrease, respectively, to thereby adjust the on" time of transistor Q3.
  • the on time of Q3 By varying the on time of Q3, the average power supplied to the load is regulated.
  • a sudden increase in load current, a decrease in load voltage, will be sensed by A1.
  • Q1 will be biased on” to supply the increased load current.
  • the change in the voltage across R1 will be sensed by A2 and the on time of Q3 adjusted to supply current to the load and increase the output voltage until Q1 reduces its output back to the predetermined maximum value.
  • Rectifier CR2 is provided to bypass sensing resistor R1 when vary large load steps occur.
  • Capacitor C2 and resistor R5 determined the particular transfer function of A2. The response time of A2 must be slow compared with the response time of A1 in order to maintain stability.
  • Q2 In the case of a sudden load removal, Q2, with associated components CR5 and CR6, will act to absorb the energy stored in L1. Q2 is normally biased for very light conduction. In some applications where a small voltage surge upon removal of the load may be acceptable, Q2 may be omitted by making Cl large in comparison to L1. Bias voltage via filter 10 is supplied to A1, A2, and pulse generator 6.
  • the area 12 comprises essentially the components of a switching regulator while area 14 comprises essentially the components of a dissipative or series-type regulator.
  • a regulated power supply comprising:
  • said dissipative-type regulator and said switching-type regulator being connected in parallel between said power source and said load terminals, wherein: said power source has first and second output terminals; said switching-type regulator comprises:
  • a first transistor having base, emitter, and collector electrodes
  • a first differential amplifier having first and second input terminals and a first output terminal, said first input terminal being resistively connected to said first load terminal, said second input terminal being resistively connected to said second load terminal;
  • said dissipative-type regulator comprises:
  • a second transistor having base, emitter, and collector electrodes
  • a second differential amplifier having first and second input terminals and an output terminal, with its output terminal connected to said base of said second transistor, its first input terminal resistively connected to said first load terminaL-and with its second input terminal resistively connected to said first and second load terminals;
  • a voltage reference circuit connected between said first input terminal of said second differential amplifier and said second load terminal; said second load terminal being connected to said second output terminal of said power source; said second input terminal of said first differential amplifier being resistively connected to said of said second transistor, said emitter being resistively connected to said 'emitter of said second transistor, and said collector being connected to said second load terminal.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Automation & Control Theory (AREA)
  • Dc-Dc Converters (AREA)

Abstract

The parallel combination of a dissipative-type regulator and a switching-type regulator is controlled by a differential amplifier to provide steady state power to a load.

Description

United. States Patent [72] Inventor William D. Wynn [56] References Cited Lake 1 UNITED STATES PATENTS 3; Q A' 35 3 2 1969 3,096,475 7/1963 Brooks 323/22 (1) m d 17'1971 3,350,628 10/1967 Gallaheret al. 323/4 1 e 3,408,559 10/1968 Bambace et al. 323 22 (T) [73] Assignee The United SlatesofAmerlcaas 3 417 321 12/1968 Cl 323,22 T
mined by'the Secretary of the Army 3,509,448 4/1970 Bland 323/22 x (T) Primary Examiner-Gerald Goldberg POWER SUPPLY HAVING PARALLEL Attorneys-Harry M. Saragovitz, Edward J Kelly, Herbert DISSIPATIVE AND SWITCHING REGULATORS Ber] and Aubrey J, Dunn 1 Claim, 1 Drawing Fig.
521 US. Cl 323/22 T, 307/242, 307/297, 323/25 ['5 i] Int. Cl. G05! 1/56 ABSTRACT: The parallel combination of a dissipative-type [50] Field of Search 323/4, 9, regulator and a switching-type regulator is controlled by a dif- 7 16-25; 307/242, 297 ferential amplifier to provide steady state power to a load.
i f 0| CR2 1, 12
l' 1: i I g 2 4 I fig FILTER 1 /Q2 I J P0 HER SOURCE I LOAD R8 \R6 5 1 Al LEE] R7 8 POWER SUPPLY HAVING PARALLEL DISSIPATIVE AND SWITCHING REGULATORS SUMMARY OF THE INVENTION A This invention relates to a low voltage-high current regulated power supply having high efficiency and a fast response time. To achieve the desired parameters, advantages is taken of the advantages of both the series or dissipative-type of regu later and theswitching-type of regulator. The series or dissipative-type of regulator offers a fast response time at the sacrifice of efficiency while the switching-type of regulator offers high efficiency at the sacrifice of response time.
To provide a power supply with the advantages of both types of regulators without the disadvantages of either, both types are used simultaneously with the outputs paralleled. Both regulators are chosen to be capable of supplying the entire load alone. The switching-type of regulator is connected as a slave to the dissipative regulator. When the current through the dissipative regulator exceeds a predetermined low level, the output from the switching regulator will increase until it is supplying the major portion of the load current. The dissipative regulator supplies current at a fast response time. The switching regulator then assumes the load current, supplying it more efficiently than does the dissipative regulator.
BRIEF DESCRIPTION OF THE DRAWING present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, under steady state conditions, all but a small percentage of the power to load is supplied through switching transistor Q3. Duty cycle control 2 switches Q3 at a fixed rate with the on time being varied as required to deliver a predetermined average voltage from power source 4 to the filter formed by inductor L1 and capacitor C1. A small keep alive current flows through transistor Q1 and constitutes the small percentage of the power to the load that is not supplied through switching transistor Q3. Amplifier Al compares the output voltage to a voltage provided by the voltage reference circuit 8 and provides an error correction signal to Q1. The output voltage signal, provided to amplifier Al, is reduced by voltage dividers R6 and R7 to a level compatible with the reference voltage. Q1 then changes the power delivered to the load until the output voltage is correct and the error signal at the input to Al is near zero. Voltage reference circuit 8 may be any device for establishing a voltage reference, Le, a zener diode. A small resistor R1 is placed in series with the output of transistor QI. Any increase or decrease in the voltage across R1 is sensed by amplifier A2 through resistor R2. Resistors R1, R2, and R3 comprise a voltage divider which, under steady state conditions, establishes a zero differential input voltage at the input of A2. During this steady state condition the current through R1 would be equal to that predetermined keep alive" current supplied through Q1.
T1 and Q4 may be considered as a blocking oscillator, but with one important difference. That difference is that the core in T1 has a very square-type hysteresis loop, preferably with a Br to Bm ratio of approximately 90 percent. Winding D of transformer T1 is a reset winding. Circuit action is initiated by a pulse from pulse generator 6, any state of the art device for delivering a pulse having a predetermined pulse repetition rate. This pulse causes O4 to saturate. With Q4 saturated, the input DC voltage causes current to flow through winding A of transformer T1 to provide outputs from windings B and C of transformer T1. The output from winding B locks Q4 in saturation. The output from winding C of T1 causes power switch Q3 to saturate and deliver power to-the LC filter composed of inductor L1 and capacitor C1. Q4 conducts until T1 saturates. When t-Tl saturates, the outputs from windings B and C of T1 reduce to zero and Q3 and Q4 cease to conduct, thus ending the power pulse. The resultant rise in collector voltage on Q4 will cause O5 to saturate and begin a reset cycle for T1. The extent to which the core is reset is determined by the time between the end of a power pulse and the beginning of the next power pulse and the DC level supplied by A2. The DC level supplied by amplifier A2 is in turn controlled by the current through R1.
An increase or decrease in the output load current from the predetermined steady state value will cause a change in voltage at the input of A2. This voltage at the input of A2 will cause the output of A2 to increase or decrease, respectively, to thereby adjust the on" time of transistor Q3. By varying the on time of Q3, the average power supplied to the load is regulated.
A sudden increase in load current, a decrease in load voltage, will be sensed by A1. Q1 will be biased on" to supply the increased load current. The change in the voltage across R1 will be sensed by A2 and the on time of Q3 adjusted to supply current to the load and increase the output voltage until Q1 reduces its output back to the predetermined maximum value. Rectifier CR2 is provided to bypass sensing resistor R1 when vary large load steps occur. Capacitor C2 and resistor R5 determined the particular transfer function of A2. The response time of A2 must be slow compared with the response time of A1 in order to maintain stability.
In the case of a sudden load removal, Q2, with associated components CR5 and CR6, will act to absorb the energy stored in L1. Q2 is normally biased for very light conduction. In some applications where a small voltage surge upon removal of the load may be acceptable, Q2 may be omitted by making Cl large in comparison to L1. Bias voltage via filter 10 is supplied to A1, A2, and pulse generator 6.
The area 12 comprises essentially the components of a switching regulator while area 14 comprises essentially the components of a dissipative or series-type regulator. I
I claim: 4
l. A regulated power supply comprising:
a dissipative-type regulator;
a switching-type regulator;
a power source; and
first and second load terminals; said dissipative-type regulator and said switching-type regulator being connected in parallel between said power source and said load terminals, wherein: said power source has first and second output terminals; said switching-type regulator comprises:
a first transistor having base, emitter, and collector electrodes;
an inductor connected between said emitter and said first load terminal;
a first differential amplifier having first and second input terminals and a first output terminal, said first input terminal being resistively connected to said first load terminal, said second input terminal being resistively connected to said second load terminal; and
said dissipative-type regulator comprises:
a second transistor having base, emitter, and collector electrodes;
a sensing resistor connected between said emitter of said second transistor and said first load terminal;
a second differential amplifier having first and second input terminals and an output terminal, with its output terminal connected to said base of said second transistor, its first input terminal resistively connected to said first load terminaL-and with its second input terminal resistively connected to said first and second load terminals;
a voltage reference circuit connected between said first input terminal of said second differential amplifier and said second load terminal; said second load terminal being connected to said second output terminal of said power source; said second input terminal of said first differential amplifier being resistively connected to said of said second transistor, said emitter being resistively connected to said 'emitter of said second transistor, and said collector being connected to said second load terminal.

Claims (1)

1. A regulated power supply comprising: a dissipative-type regulator; a switching-type regulator; a power source; and first and second load terminals; said dissipative-type regulator and said switching-type regulator being connected in parallel between said power source and said load terminals, wherein: said power source has first and second output terminals; said switching-type regulator comprises: a first transistor having base, emitter, and collector electrodes; an inductor connected between said emitter and said first load terminal; a first differential amplifier having first and second input terminals and a first output terminal, said first input terminal being resistively connected to said first load terminal, said second input terminal being resistively connected to said second load terminal; and said dissipative-type regulator comprises: a second transistor having base, emitter, and collector electrodes; a sensing resistoR connected between said emitter of said second transistor and said first load terminal; a second differential amplifier having first and second input terminals and an output terminal, with its output terminal connected to said base of said second transistor, its first input terminal resistively connected to said first load terminal, and with its second input terminal resistively connected to said first and second load terminals; a voltage reference circuit connected between said first input terminal of said second differential amplifier and said second load terminal; said second load terminal being connected to said second output terminal of said power source; said second input terminal of said first differential amplifier being resistively connected to said emitter of said second transistor; said first output terminal of said power source being connected to said collectors of said first and second transistors; and a third transistor having base, emitter, and collector electrodes, said base being connected to said base electrode of said second transistor, said emitter being resistively connected to said emitter of said second transistor, and said collector being connected to said second load terminal.
US858399A 1969-09-16 1969-09-16 Power supply having parallel dissipative and switching regulators Expired - Lifetime US3600667A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US85839969A 1969-09-16 1969-09-16

Publications (1)

Publication Number Publication Date
US3600667A true US3600667A (en) 1971-08-17

Family

ID=25328225

Family Applications (1)

Application Number Title Priority Date Filing Date
US858399A Expired - Lifetime US3600667A (en) 1969-09-16 1969-09-16 Power supply having parallel dissipative and switching regulators

Country Status (1)

Country Link
US (1) US3600667A (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2543441A1 (en) * 1974-10-03 1976-04-15 United Technologies Corp LINEAR ENERGY HOLDING POWER SOURCE
US4142113A (en) * 1976-04-05 1979-02-27 Telefonaktiebolaget L M Ericsson Current pulse circuit for ferrite core memories
DE2933029A1 (en) * 1978-08-16 1980-02-28 Lucas Industries Ltd POWER ADAPTER
DE3340395A1 (en) * 1982-11-22 1984-05-24 General Motors Corp., Detroit, Mich. VOLTAGE REGULATOR
EP0377537A3 (en) * 1989-01-06 1990-10-10 Uniphase Corporation Circuit for providing fast output current control in a current mode switching power supply
US5329224A (en) * 1993-10-20 1994-07-12 Ford Motor Company Automotive voltage regulator circuit including serial voltage regulators
US5629608A (en) * 1994-12-28 1997-05-13 Intel Corporation Power regulation system for controlling voltage excursions
DE19917204A1 (en) * 1999-04-16 2000-10-19 Bosch Gmbh Robert Circuit generating stabilized supply voltage for electronic consumer appliances in cars from fluctuating car network voltage
US20070024360A1 (en) * 2005-07-27 2007-02-01 Artesyn Technologies, Inc. Power supply providing ultrafast modulation of output voltage
US20080224769A1 (en) * 2007-03-13 2008-09-18 Piotr Markowski Power supply providing ultrafast modulation of output voltage
US7994761B2 (en) 2007-10-08 2011-08-09 Astec International Limited Linear regulator with RF transistors and a bias adjustment circuit
DE102016100188A1 (en) * 2016-01-05 2017-07-06 Eaton Electrical Ip Gmbh & Co. Kg Control device for an electromagnetic drive of a switching device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3096475A (en) * 1958-05-16 1963-07-02 Thompson Ramo Wooldridge Inc Electrical apparatus
US3350628A (en) * 1964-07-16 1967-10-31 Bell Telephone Labor Inc Current regulator with a. c. and d. c. feedback
US3408559A (en) * 1966-08-10 1968-10-29 Gen Precision Systems Inc Line voltage stabilizer having parallel dynamic and stable impedance paths
US3417321A (en) * 1968-12-17 Nasa Increasing efficiency of switching-type regulator circuits
US3509448A (en) * 1968-06-03 1970-04-28 Hewlett Packard Co Power supply voltage regulator having power sharing regulating transistors and current limiting means

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3417321A (en) * 1968-12-17 Nasa Increasing efficiency of switching-type regulator circuits
US3096475A (en) * 1958-05-16 1963-07-02 Thompson Ramo Wooldridge Inc Electrical apparatus
US3350628A (en) * 1964-07-16 1967-10-31 Bell Telephone Labor Inc Current regulator with a. c. and d. c. feedback
US3408559A (en) * 1966-08-10 1968-10-29 Gen Precision Systems Inc Line voltage stabilizer having parallel dynamic and stable impedance paths
US3509448A (en) * 1968-06-03 1970-04-28 Hewlett Packard Co Power supply voltage regulator having power sharing regulating transistors and current limiting means

Cited By (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2543441A1 (en) * 1974-10-03 1976-04-15 United Technologies Corp LINEAR ENERGY HOLDING POWER SOURCE
US4142113A (en) * 1976-04-05 1979-02-27 Telefonaktiebolaget L M Ericsson Current pulse circuit for ferrite core memories
DE2933029A1 (en) * 1978-08-16 1980-02-28 Lucas Industries Ltd POWER ADAPTER
DE3340395A1 (en) * 1982-11-22 1984-05-24 General Motors Corp., Detroit, Mich. VOLTAGE REGULATOR
US4459537A (en) * 1982-11-22 1984-07-10 General Motors Corporation Up-down voltage regulator
EP0377537A3 (en) * 1989-01-06 1990-10-10 Uniphase Corporation Circuit for providing fast output current control in a current mode switching power supply
US5329224A (en) * 1993-10-20 1994-07-12 Ford Motor Company Automotive voltage regulator circuit including serial voltage regulators
US5629608A (en) * 1994-12-28 1997-05-13 Intel Corporation Power regulation system for controlling voltage excursions
DE19917204A1 (en) * 1999-04-16 2000-10-19 Bosch Gmbh Robert Circuit generating stabilized supply voltage for electronic consumer appliances in cars from fluctuating car network voltage
US6249110B1 (en) 1999-04-16 2001-06-19 Robert Bosch Gmbh Circuit configuration for generating a stabilized power supply voltage
US20070024360A1 (en) * 2005-07-27 2007-02-01 Artesyn Technologies, Inc. Power supply providing ultrafast modulation of output voltage
US7602155B2 (en) 2005-07-27 2009-10-13 Artesyn Technologies, Inc. Power supply providing ultrafast modulation of output voltage
US20090261908A1 (en) * 2005-07-27 2009-10-22 Artesyn Technologies, Inc. Power supply providing ultrafast modulation of output voltage
US7990214B2 (en) 2005-07-27 2011-08-02 Artesyn Technologies, Inc. Power supply providing ultrafast modulation of output voltage
US20080224769A1 (en) * 2007-03-13 2008-09-18 Piotr Markowski Power supply providing ultrafast modulation of output voltage
US20090184764A1 (en) * 2007-03-13 2009-07-23 Piotr Markowski Power supply providing ultrafast modulation of output voltage
US7808313B2 (en) 2007-03-13 2010-10-05 Astec International Limited Power supply providing ultrafast modulation of output voltage
US7859336B2 (en) 2007-03-13 2010-12-28 Astec International Limited Power supply providing ultrafast modulation of output voltage
US7994761B2 (en) 2007-10-08 2011-08-09 Astec International Limited Linear regulator with RF transistors and a bias adjustment circuit
DE102016100188A1 (en) * 2016-01-05 2017-07-06 Eaton Electrical Ip Gmbh & Co. Kg Control device for an electromagnetic drive of a switching device
US10937616B2 (en) 2016-01-05 2021-03-02 Eaton Intelligent Power Limited Control device for an electromagnetic drive of a switchgear

Similar Documents

Publication Publication Date Title
US4316242A (en) Wide input range, transient-immune regulated flyback switching power supply
US3771040A (en) Regulated dc-to-dc converter for voltage step-up or step-down with input-output isolation
US3600667A (en) Power supply having parallel dissipative and switching regulators
US3541420A (en) Voltage converter and regulator
US3327199A (en) Transistorized high voltage regulated power supply system with temperature compensating means
US3305756A (en) Combined gated pulse source-transverter-rectifier power supply with sampling connection for regulation
US3241044A (en) Thyratron tube replacement units employing controlled rectifiers and a control transitor
US3213351A (en) Firing pulse generating circuit for solid state controlled rectifiers
US4001665A (en) High efficiency power supply having a reactive buck automatic d.c. voltage regulator
US3312911A (en) Tunnel diode relaxation oscillator
US3067378A (en) Transistor converter
US3974439A (en) Wide dynamic current range switching regulator
US4791348A (en) Switching ac voltage regulator
US3846694A (en) Constant power supply employing a variable frequency inverter
CN101158878A (en) Switching resistance linear regulator architecture
US3461377A (en) Blocking oscillator d.c. voltage regulator
US3599083A (en) Switching means for the regulation of a dc voltage
US3898549A (en) Variable duty cycle balanced DC/DC power converter
US3356927A (en) Regulated power supply circuit
US3629682A (en) Inverter with zener-regulated output frequency and voltage
US4085358A (en) Regulated DC to DC power supply with automatic recharging capability
JPH09121454A (en) Power supply that improves transient response to variation in load
US3708739A (en) Regulated electrical inverter system
US3191115A (en) Direct-current to alternating-current inverter
US3676768A (en) Source independent power supply