Stabilizing power-supply circuit

• US 4,510,562 A
• Filed: 09/27/1983
• Issued: 04/09/1985
• Est. Priority Date: 09/28/1982
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Maeba, Yukio
• Primary Examiner(s): Wong, Peter S.
• Application Number:
  US06/536,198
• Time in Patent Office: 560 Days
• Field of Search: 363/18-21, 363/78, 363/95, 363/97, 363/124, 363/131, 331/112
• US Class Current: 363/19
• CPC Class Codes: H02M 3/33507 with automatic control of the output voltage or current, e.g. flyback converters H02M3/33561, H02M3/33569 take precedence

Abstract

A stabilizing power-supply circuit adapted to apply the output signals of a comparison amplifier directly upon the base circuit of the oscillation transistor of an oscillating circuit through a zener diode. The oscillation is reduced to a given output voltage during the no-load thereby to protect the power-supply apparatus.

Claims

1. A stabilizing power-supply circuit comprising an oscillation circuit of collector tuning type including a base circuit of an oscillation transistor and a tuning coil, an output circuit including an output coil, which is magnetically coupled to the tuning coil of the oscillation circuit, for producing an output voltage, a detection circuit for detecting the variation in the output of the output circuit, a comparison amplifier of single ended supply type for the comparison between the signal from the detection circuit and a reference voltage, and for amplifying the difference therebetween, and a zener diode of which cathode is connected to the comparison amplifier, the output voltage of the comparison amplifier being adapted to be applied upon the base circuit of the oscillation transistor through the zener diode and being set to become lower than the zener voltage of the zener diode in the no-load condition.

2. The stabilizing power-supply circuit defined in claim 1, wherein the detection circuit comprises at least one resistor connected to the output circuit.

3. The stabilizing power-supply circuit defined in claim 1, wherein the detection circuit comprises a detecting coil magnetically coupled to the output coil of the output circuit.

4. The stabilizing power-supply circuit defined in claim 1, wherein the zener diode has a characteristic of a gentle curve in rising of current relating to voltage.

5. The stabilizing power-supply circuit as defined in claim 1, wherein the detection circuit is adapted to apply a constant voltage, so that the stabilizing power-supply circuit is constituted as a constant voltage power supply of constant voltage control.

6. The stabilizing power-supply circuit as defined in claim 1, wherein the detection circuit is adapted to apply a constant current, so that the stabilizing power-supply circuit is constituted as a constant current power supply of constant current control.

7. The stabilizing power-supply circuit defined in claim 2, wherein the zener diode has a characteristic of a gentle curve in rising of current relating to voltage.

8. The stabilizing power-supply circuit as defined in claim 2, wherein the detection circuit is adapted to apply a constant voltage, so that the stabilizing power-supply circuit is constituted as a constant voltage power supply of constant voltage control.

9. The stabilizing power-supply circuit as defined in claim 2, wherein the detection circuit is adapted to aply a constant current, so that the stabilizing power-supply circut is constituted as a constant current power supply of constant current control.

10. The stabilizing power-supply circuit defined in claim 3, wherein the zener diode has a characteristic of a gentle curve in rising of current relating to voltage.

11. The stabilizing power-supply circuit as defined in claim 3, wherein the detection circuit is adapted to apply a constant voltage, so that the stabilizing power-supply circuit is constituted as a constant voltage power supply of constant voltage control.

12. The stabilizing power-supply circuit as defined in claim 4, wherein the detection circuit is adapted to apply a constant voltage, so that the stabilizing power-supply circuit is constituted as a constant voltage power supply of constant voltage control.

13. The stabilizing power-supply circuit as defined in claim 7, wherein the detection circuit is adapted to apply a constant voltage, so that the stabilizing power-supply circuit is constituted as a constant voltage power supply of constant voltage control.

14. The stabilizing power-supply circuit as defined in claim 10, wherein the detection circuit is adapted to apply a constant voltage, so that the stabilizing power-supply circuit is constituted as a constant voltage power supply of constant voltage control.