Power supply apparatus

• US 20010055216A1
• Filed: 04/06/2001
• Published: 12/27/2001
• Est. Priority Date: 04/07/2000
• Status: Active Grant

• Current Assignee: Saturn Licensing LLC (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Shirato, Keiji
• Granted Patent: US 6,434,024 B2
• Time in Patent Office: Days
• US Class Current: 363/21.07
• CPC Class Codes: H02J 9/007 Detection of the absence of a load
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 7/217 using semiconductor devices only
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A power supply apparatus is provided with a power supply transformer; excitation circuit portions provided at a primary side of the power supply transformer, for exciting the power supply transformer by means of a commercial power supply; and control circuit portions provided at a secondary side of the power supply transformer, for starting operation by the power supply transformer having entered an excited state and for intermittently operating the excitation circuit portion 50. Thereby, power in a waiting state can be suppressed at maximum and energy saving can be executed further efficiently.

Claims

1. A power supply apparatus, comprising:

a power supply transformer;

an excitation circuit portion to be provided on a primary side of said power supply transformer and to excite said power supply transformer with an alternating current power supply; and

a control circuit portion provided on a secondary side of said power supply transformer, to start an operation by said power supply transformer in an excitation state, and to cause said excitation circuit portion to operate intermittently.

2. The power supply apparatus according to

claim 1

, wherein

said excitation circuit portion comprises:

a switching element to switch supply of said alternating current power supply to said power supply transformer;

a direct current voltage generating circuit to generate a direct current voltage for causing said switching element to operate; and

a photocoupler to insulate said excitation circuit portion and said control circuit portion in between and to intermediate a control signal outputted from said control circuit portion to said switching element.

3. The power supply apparatus according to

claim 2

, wherein

said direct current voltage generating circuit supplies said switching element with said direct current voltage when supply of said alternating current voltage supply starts.

4. The power supply apparatus according to

claim 3

, wherein

said direct current voltage generating circuit contains a switching voltage accumulating capacitor, and supplies said switching element with a charged voltage of said switching voltage accumulating capacitor by said alternating current voltage supply.

5. The power supply apparatus according to

claim 4

, wherein

said switching element comprises bridge diodes and a FET switch connecting them in the middle point.

6. The power supply apparatus according to

claim 4

, wherein

said switching element comprises bridge diodes and a thyristor switch connecting them in the middle point.

7. The power supply apparatus according to

claim 4

, wherein

said switching element comprises bridge diodes and an IGBT connecting them in the middle point.

8. The power supply apparatus according to

claim 4

, wherein:

in said switching element, two FET connected to each other in series is connected to a limiting resistance in series, and said the resistance connected to the two FET in series is connected to a triac in parallel.

9. The power supply apparatus according to

claim 1

, wherein:

said control circuit portion;

halts the excitation operation of said power supply transformer by said excitation circuit portion when the charged voltage value of a secondary side voltage accumulating capacitor charged by said power supply transformer in said excitation state exceeds a first threshold level; and

after said power supply transformer halts the excitation operation, resumes the excitation operation of said power supply transformer by said excitation circuit portion when a charged voltage value of said secondary side voltage accumulating capacitor drops due to a discharge to reach lower than a second threshold level.

10. The power supply apparatus according to

claim 5

, wherein:

said excitation circuit portion comprises;

a switching element to switch supply of said alternating current power supply to said power supply transformer;

a direct current voltage generating circuit to generate a direct current voltage for causing said switching element to operate; and

a photocoupler to insulate said excitation circuit portion and said control circuit portion in between and to intermediate a control signal outputted from said control circuit portion to said switching element, and wherein

said control circuit portion resumes the excitation operation of said power supply transformer by said excitation circuit portion with said photocoupler of said excitation circuit portion to intermediate when a charged voltage value of said secondary side voltage accumulating capacitor drops due to a discharge to reach lower than a second threshold level.

11. The power supply apparatus according to

claim 10

, wherein

said control circuit portion controls a predetermined current to be supplied to said photocoupler in case of halting the excitation operation of said power supply transformer by said excitation circuit portion.

12. The power supply apparatus according to

claim 10

, wherein

said control circuit portion is selected to have a large time constant including said secondary side voltage accumulating capacitor.

13. The power supply apparatus according to

claim 10

, wherein

when said photcoupler is in an ON condition, said switching element supplies said alternating current power to said transformer.

14. The power supply apparatus according to

claim 11

, wherein

an field effect transistor to switch supply of said alternating current power supply is used for said switching element.

15. The power supply apparatus according to

claim 10

, wherein

a momentary switch is provided in parallel on the output end, in order to make said switching element be in an ON state by hand operation.