Power supply with uninterruptible function

• US 7,053,502 B2
• Filed: 03/26/2004
• Issued: 05/30/2006
• Est. Priority Date: 12/25/1998
• Status: Expired due to Fees

• Current Assignee: Hitachi Information & Telecommunication Engineering, Ltd. (Hitachi, Ltd.)
• Original Assignee: Hitachi Computer Peripherals Company Limited (Hitachi, Ltd.), Hitachi, Ltd.
• Inventors: Onda, Kenichi, Masuyama, Satoru, Tokunaga, Norikazu, Onaka, Takeshi, Zemba, Shigekazu, Aihara, Nobuyuki
• Primary Examiner(s): Laxton, Gary L
• Application Number:
  US10/809,863
• Publication Number:
  US 20050078494A1
• Time in Patent Office: 795 Days
• Field of Search: 363/34, 363/37, 363/39, 307 44- 46, 307/48, 307/64, 307/66, 307/80
• US Class Current: 307/46
• CPC Class Codes: H02J 9/061 for DC powered loads

Abstract

A power supply provided with: an AC/DC converter which receives AC power, converts the AC power into DC power, and outputs the DC power; a DC/DC converter which receives the DC power from the AC/DC converter, and controls a level of an output voltage of the DC/DC converter to be equal to a level of a voltage to be used by a load while the DC/DC converter supplies the output voltage to the load; a DC converter which is connected to an input of the DC/DC converter; and a DC power storage means which supplies electric power to the DC/DC converter through the DC converter.

Claims

1. A power supply comprising:

an AC/DC converter which converts an input AC power into DC power and outputs the DC power to an output terminal thereof, said AC/DC converter having power factor improvement function;

a DC/DC converter having an input terminal connected to the output terminal of said AC/DC converter, said DC/DC converter converting a DC voltage inputted thereto into a voltage value to be applied to a load;

a DC converter having a first terminal connected to the output terminal of said AC/DC converter and the input terminal of said DC/DC converter; and

DC power storage means which is connected to a second terminal of said DC converters, and which supplies said DC/DC converter with a DC power through said DC converter;

wherein said load is supplied with the DC power from said AC/DC converter through said DC/DC converter, and said DC power storage means connected to said second terminal of said DC converter is supplied with the DC power from said AC/DC converter for charging using a path through the output terminal of said AC/DC converter, the first terminal of said DC converter and said DC converter; and

wherein, said DC converter comprising an actuating signal generating portion having an AND logic circuit, and said AND logic circuit is supplied with a power interruption detecting signal and an actuating command, and

when the input AC power is not applied to said AC/DC converter and said actuating command is ON, said load is supplied with the DC power from said DC power storage means using a path through said second terminal, said DC converter, said first terminal and said DC/DC converter in order.

2. A power supply according to claim 1, wherein said DC converter comprises:

a first converter having an AC terminal, and a DC terminal which is said first terminal connected to the input terminal of said DC/DC converter;

a transformer having a high-voltage side winding connected to the AC terminal of said first converter, and a low-voltage side winding; and

a second converter having an AC terminal connected to the low-voltage side winding, and a DC terminal which is said second terminal connected to said DC power storage means.

3. A power supply according to claim 1, wherein said DC power storage means is a secondary battery or a capacitor.

4. A power supply according to claim 1, wherein said AC/DC converter is supplied with commercial AC power of 100 V to 200 V.

5. A power supply according to claim 1, wherein said DC power storage means voltage is 40 V to 50 V.

6. A power supply comprising:

an AC/DC converter which converts an input AC power into DC power and outputs the DC power to an output terminal thereof;

a DC/DC converter having an input terminal connected to the output terminal of said AC/DC converter, said DC/DC converter converting a DC voltage inputted thereto into a voltage to be applied to a load;

a DC converter having a first terminal connected to the output terminal of said AC/DC converter and the input terminal of said DC/DC converter; and

a DC power storage unit which is connected to a second terminal of said DC converter to receive storage power, and which supplies said DC/DC converter with a DC power through said DC converter;

wherein said load is supplied with the DC power from said AC/DC converter through said DC/DC converter, and said DC power storage unit connected to said second terminal of said DC converter is supplied with the DC power from said AC/DC converter for charging using a path through the output terminal of said AC/DC converter, the first terminal of said DC converter and said DC converter; and

wherein, said DC converter comprising a back-up power actuating unit including an AND logic circuit, and where differing inputs of the AND logic circuit are supplied with a power interruption detecting signal and a back-up power actuating command signal, and when both the power interruption detecting signal indicates that input AC power is not applied to said AC/DC converter and the actuating command signal enables back-up power, said load is supplied with the DC power from said DC power storage unit using a path through said second terminal, said DC converter, said first terminal and said DC/DC converter.

7. A power supply according to claim 6, wherein said DC converter comprises:

a first converter having an AC terminal, and a DC terminal which is said first terminal connected to the input terminal of said DC/DC converter;

a transformer having a high-voltage side winding connected to the AC terminal of said first converter, and a low-voltage side winding; and

a second converter having an AC terminal connected to the low-voltage side winding, and a DC terminal which is said second terminal connected to said DC power storage unit.

8. A power supply according to claim 6, wherein said DC power storage unit is a secondary battery or a capacitor.

9. A power supply according to claim 6, wherein said AC/DC converter is supplied with commercial AC power of 100 V to 200 V.

10. A power supply according to claim 6, wherein said DC power storage unit voltage is 40 V to 50 V.