Regulator circuit for converting alternating input to a constant direct output

• US 4,754,388 A
• Filed: 12/19/1986
• Issued: 06/28/1988
• Est. Priority Date: 07/15/1985
• Status: Expired due to Term

• Current Assignee: Intersil Corporation (Renesas Electronics Corporation)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Pospisil, Robert S.
• Primary Examiner(s): Beha, Jr., William H.
• Application Number:
  US07/944,399
• Time in Patent Office: 557 Days
• Field of Search: 323/266, 323/299, 323/300, 323/282, 323/284, 363/86, 363/89, 363/80, 363/81, 363/54
• US Class Current: 363/54
• CPC Class Codes: G05F 1/563 including two stages of regulation at least one of which is output level responsive, e.g. coarse and fine regulation

Abstract

A high efficiency integrated power converter adapted for direct connection to line voltage and having on chip protection from overcurrent may be implemented utilizing a GTO-SCR as the switch element in a switching power converter such that the converter requires no external transformer or inductor based voltage reducing circuitry. The input voltage may vary over a wide dynamic range without deterioration in circuit performance due to the extremely high anode to cathode breakdown voltage of the switching element and further due to the on chip protection from excess current flow through the switching element.

Claims

1. A regulator of a high efficiency switching power supply suitable for direct connection between and AC line and a charge storage means comprising:

a switching means having an input coupled to said AC line and an output coupled to said charge storage means,

wherein said switching means inhibits current flow from said AC line to said charge storage means when said switching means is opened,

wherein said switchng means includes a biasing means for opening said switching means when said voltage at the charge storage means is greater than the voltage of a first predetermined reference voltage, and

when said voltage at said AC input line is greater than a second predetermined reference voltage, and

when said voltage at said AC input line is less than the voltage at said charge storage means,

wherein said switching means further includes a gate turn off SCR having an input connected to said AC line, an output terminal connected to said charge storage means, and a control terminal.

2. The regulator of claim 1, wherein said gate turn off SCR includes a PNP and an NPN transistor, and a first and a second resistor, said PNP transistor having a base connected to a collector of said NPN transistor and to said AC line via said first resistor, a collector connected to a base of said NPN transistor, and an emitter coupled to said AC line via said second resistor, said NPN transistor further having its emitter connected to said charge storage means.

3. The regulator of claim 1, wherein said biasing means includes a threshold gating means connected to said control terminal of said SCR and connected between said AC line and said charge storage means for providing said first predetermined reference voltage for biasing said gate turn off SCR in response to said reference voltage.

4. The regulator of claim 3, wherein said biasing means further includes a lockout circuit means connected to said control terminal of said SCR and between said AC line and said charge storage means for providing said second predetermined reference voltage and for biasing said gate turn off SCR in response to said reference voltage.

5. An integrated AC to DC converter for direct connection to a high voltage AC line comprising:

a rectification means,

a voltage preregulator comprising a GTO-SCR having an anode connected to said rectification means and a cathode connected to both of a voltage post regulator and a charge storage means,

a zener diode having its anode connected to a regulated DC output terminal of said post regulator and its cathode connected to the anode of a diode having its cathode connected to a gate of said GTO-SCR,

a PNP transistor having its emitter connected to said gate of said GTO-SCR, and having is collector connected to said cathode of said GTO-SCR and its base connected to said cathode of said zener diode,

an NPN transistor having its collector connected to said base of said PNP transistor, and having its emitter connected to said collector of said PNP transistor and having its base connected to said rectification means and to said cathode of said GTO-SCR, and

a first resistor connected between said rectifying means and said cathode of said diode.

6. A switching power supply on a single semiconductor chip suitable for direct connection between a first and second terminal of an AC source and a high and low side of a charge storage means, said power supply comprising:

a switching means having an input connected to said first terminal of said AC source for receiving an input signal, an output connected to said high side of said charge storage means for providing said input signal to said charge storage means when said switch is closed, and a control terminal for controllng said switch;

a threshold gating means connected between said first terminal of said AC source and said high side of said charge storage means and connected to said control terminal of said switching means for closing said switching means when a voltage on said first terminal of said AC source is greater than a voltage at said high side of said charge storage means, and opening said switching means when said voltage at said charge storage means is greater than a first predetermined reference voltage; and

a lockout means coupled between said first terminal of said AC source and said threshold means for opening said switching means when said voltage on said first terminal of said AC source is greater than a second predetermined reference voltage wherein said switching means includes a first PNP and first NPN transistor, said first PNP transistor having a base connected to a collector of said first NPN transistor and to said first side of said AC source, a collector connected to a base of said first NPN transistor, and an emitter coupled to said first side of said AC source, said first NPN transistor further having its emitter connected to said high side of said charge storage means.

7. The power supply of claim 6, wherein said gate turn off SCR further includes a first and second current limiting resistor, said first resistor coupled between said first side of said AC source and said collector of said PNP transistor and said second resistor coupled between said first side of said AC source and the emitter of said PNP transistor.

8. The power supply of claim 6, further including a post voltage regulator means coupled between said high and low side of said charge storage means, said post regulator having an output for providing a regulated output voltage.

9. The power supply of claim 8, wherein said threshold gating means includes a current path from said first side of said AC source to said base of said first NPN transistor via a third resistor and a first diode, a second PNP transistor having its emitter connected to both the base of said first NPN transistor and to a cathode of said first diode, its collector connected to said high side of said charge storage means and its base to an anode of said first diode, and a first zener diode having its cathode connected to said base of said second PNP transistor and its anode connected to said output of said post regulator means, wherein said first predetermined reference voltage is derived from said regulated output voltage and a reverse breakdown zener voltage.

10. The power supply of claim 9, wherein said lockout means includes a second NPN transistor having its collector coupled to said anode of said first diode, its emitter connected to said high side of said charge storage means, and its base connected to said high side of said AC source via a fourth resistor and to its emitter via a fifth resistor, wherein said second predetermined reference voltage is derived from the voltage across the fifth resistor.

11. The power supply of claim 6, further comprising a rectifying means connected between said high side of said AC source and said input of said switch means.

12. A voltage regulator of a high efficiency switching power supply on a single semiconductor chip switch suitable for direct connection to an AC line comprising:

a switching means for providing a connection of said AC line to a charge storage means, wherein said switch means includes an input connected to the AC line for receiving an input signal, an output connected to said charge storage means, and a control terminal, wherein said switching means provides said input signal to said charge storage means when said switch is biased on and inhibits said input signal from passing to said charge storage means when said switch is biased off,

a voltage protection means including means for providing a first predetermined reference voltage and means for providing a second reference voltage, said voltage protection means being connected to said control terminal and between said AC line and said charge storage means for biasing said switching means to be off when a voltage across said charge storage means is greater than a first predetermined reference voltage or when said voltage at said AC line is greater than said second predetermined reference voltage, and

a current protection means connected between said AC line and said switching means for detecting an input current from said AC line and biasing said switching means to be off when said current is greater than a predetermined magnitude.

13. The regulator of claim 12, wherein said switching means includes a gate turn off SCR.

14. The regulator of claim 13, wherein said gate turn off SCR includes a first NPN transistor having its collector coupled to said AC line, its emitter connected to said charge storage means and its base connected to said voltage protection means and a first PNP transistor having its collector connected to said base of said first NPN transistor, its emitter connected to said AC line, and its base connected to said collector of said first NPN transistor.

15. The regulator of claim 14, further including a voltage post regulator connected between said charge storage means and an output, for providing a substantially regulated selected voltage at said output.

16. The regulator of claim 15, wherein said means for providing said first predetermined reference includes a second PNP transistor having its collector collected to said charge storage means, its emitter connected to said base of said first NPN transistor, and its base connected to a first side of said AC line via a first transistor;

a first diode having its cathode connected to said emitter of said second PNP transistor and its anode connected to said base of said second PNP transistor; and

a first zener diode having its cathode connected to said AC line via said first resistor and its anode connected to said output of said voltage post regulator.

17. The regulator of claim 16, wherein said voltage post regulator includes a third PNP transistor having its emitter connected to a first terminal of said charge storage means, its collector to said output and its base to a third NPN transistor, said third transistor having its base connected to said emitter of said third PNP transistor via a second resistor and to a cathode of a second zener diode, and its emitter coupled to an emitter of a fourth NPN transistor and to a second terminal of said charge storage means via a third resistor, said fourth NPN transistor having its collector connected to said emitter of said third PNP transistor and its base connected to said second terminal of said charge storage means via a fourth resistor, and to said output via an adjustable resistor.

18. The regulator of claim 16, wherein said means for providing said second predetermined reference voltage includes a second NPN transistor having its collector connected to said AC line via a second resistor, its emitter connected to said AC line via a third resistor and its base connected to its emitter via a fourth resistor.

19. A high efficiency switching power supply having an input for receiving an AC signal and an output for providing a regulated DC signal, said switching power supply comprising:

a regulator connected between said input and a charge storage means, and a post regulator connected between said charge storge means and said output,

wherein said regulator includes a switching means having a first terminal connected to said input, a second terminal connected to said charge storage means, and a control gate terminal, wherein said switching means provides a conductive path between said input and said charge storage means when said switching means is biased on; and

a biasing means having a first means for producing a first predetermined reference voltage and a second means for producing a second predetermined reference voltage, said biasing means is connected to said control gate terminal and between said input and said output for biasing said control gate terminal for biasing said switching means on when an AC voltage at said input is greater than said voltage across said charge storage means, and said AC voltage is less than said first predetermined reference voltage, and said voltage across said charge storage means is less than said second predetermined reference voltage, and

wherein said output of said post regulator is connected to said second means for producing said second predetermined reference voltage, whereby said voltage at the output of the regulator tracks the voltage across the charge storage means.

20. The power supply of claim 19, wherein said switching means includes a gate turn off SCR.

21. The power supply of claim 19, wherein said biasing means includes a first zener diode, a second diode, and a three terminal switch, said three terminal switch having a first terminal connected to said control gate terminal of said switching means, and a cathod of said second diode, a second terminal connected to said charge storage means, and a control terminal connected to said input via a resistor and to a cathode first zener diode, said first zener diode having its anode connected to said output, wherein said three terminal switch is operative to divert current from said control terminal of said switching means and thereby cause said switching means to cease conducting in response to an AC line potential exceeding a voltage equal to a regulated output DC voltage plus said first zener diode reverse breakdown voltage.

22. The power supply of claim 21, wherein said post regulator includes a means for selecting the magnitude of the regulated output DC voltage, wherein said post regulator in combination with said first zener diode provides a selected DC output while dissipating substantially the same power across it independent of the magnitude selected for said regulated output DC voltage.