Power supply device and recording apparatus

• US 7,746,049 B2
• Filed: 03/26/2008
• Issued: 06/29/2010
• Est. Priority Date: 03/30/2007
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sato, Takashi
• Primary Examiner(s): Laxton; Gary L
• Application Number:
  US12/056,114
• Publication Number:
  US 20080238388A1
• Time in Patent Office: 825 Days
• Field of Search: 323/220, 323/223, 323/229, 323/265, 323/282, 323/288, 323/351, 320/166
• US Class Current: 323/288
• CPC Class Codes: H02M 1/322 Means for rapidly discharging a capacitor of the converter for protecting electrical components or for preventing electrical shock
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load

Abstract

A power supply device includes a DC-DC converter configured to regulate an output voltage based on an externally input instruction, and a discharge circuit connected to an output capacitor of the DC-DC converter, wherein the discharge circuit includes a switch element configured to switch between a conductive state and a nonconductive state according to an instruction, and a capacitor-resistor (C-R) circuit configured to charge electric charge accumulated in the output capacitor of the DC-DC converter when the switch element is conductive and to discharge the electric charge to ground when the switch element is nonconductive.

Claims

1. A power supply device comprising:

a DC-DC converter configured to regulate an output voltage based on an externally input instruction; and

a discharge circuit connected to an output capacitor of the DC-DC converter, wherein the discharge circuit includes,

a switch element configured to switch between a conductive state and a nonconductive state according to an instruction; and

a capacitor-resistor (C-R) circuit configured to charge electric charge accumulated in the output capacitor of the DC-DC converter when the switch element is conductive and to discharge the electric charge to ground while the switch element is nonconductive.

2. The power supply device according to claim 1, wherein one end of the switch element is connected to an output voltage line of the DC-DC converter via a first resistor and the other end of the switch element is connected to the C-R circuit.

3. The power supply device according to claim 2, wherein the C-R circuit includes a resistor and a capacitor connected in series between the other end of the switch element and the ground.

4. The power supply device according to claim 1, wherein one end of the switch element is connected to an output voltage line of the DC-DC converter and the other end of the switch element is connected to the C-R circuit.

5. The power supply device according to claim 4, wherein the C-R circuit includes a resistor and a capacitor connected in series between the other end of the switch element and the ground.

6. The power supply device according to claim 2, wherein a time constant of the C-R circuit is smaller than an interval of conduction timing of the switch element.

7. A power supply device comprising:

a DC-DC converter configured to regulate an output voltage based on an externally input instruction; and

a discharge circuit connected to an output line of the DC-DC converter, wherein the discharge circuit includes,

a switch element configured to switch between a conductive state and a nonconductive state according to an instruction; and

a capacitor-resistor (C-R) circuit configured to charge electric charge of an output capacitor of the DC-DC converter when the switch element is conductive and to discharge the electric charge to ground when the switch element is nonconductive.

8. A recording apparatus comprising:

a power supply device including,

a DC-DC converter configured to regulate an output voltage based on an externally input instruction; and

a discharge circuit connected to an output capacitor of the DC-DC converter, wherein the discharge circuit includes,

a switch element configured to switch between a conductive state and a nonconductive state according to an instruction; and

a capacitor-resistor (C-R) circuit configured to charge electric charge accumulated in the output capacitor of the DC-DC converter when the switch element is conductive and to discharge the electric charge to ground while the switch element is nonconductive; and

a control unit configured to control an operation of the recording apparatus, wherein the control unit outputs an instruction for changing the output voltage to the DC-DC converter and the discharge circuit.

9. A recording apparatus comprising:

a power supply device including,

a DC-DC converter configured to regulate an output voltage based on an externally input instruction; and

a discharge circuit connected to an output capacitor of the DC-DC converter,

wherein the discharge circuit includes,

a switch element configured to switch between a conductive state and a nonconductive state according to an instruction; and

a capacitor-resistor (C-R) circuit configured to charge electric charge accumulated in the output capacitor of the DC-DC converter when the switch element is conductive and to discharge the electric charge to ground while the switch element is nonconductive; and

a control unit configured to control an operation of the recording apparatus, wherein the control unit outputs an instruction to the switch element such that a nonconduction period of the switch element becomes longer than a conduction period of the switch element.

10. A recording apparatus comprising:

a power supply device including,

a DC-DC converter configured to regulate an output voltage based on an externally input instruction; and

a discharge circuit connected to an output line of the DC-DC converter, wherein the discharge circuit includes,

a switch element configured to switch between a conductive state and a nonconductive state according to an instruction; and

a capacitor-resistor (C-R) circuit configured to charge electric charge of an output capacitor of the DC-DC converter when the switch element is conductive and to discharge the electric charge to ground when the switch element is nonconductive; and

a control unit configured to control an operation of the recording apparatus, wherein the control unit outputs an instruction for changing the output voltage to the DC-DC converter and the discharge circuit.