Discharge device, power supply apparatus, and discharge method with power supply cut-off detection and capacitor discharge

• US 10,560,035 B2
• Filed: 05/16/2016
• Issued: 02/11/2020
• Est. Priority Date: 07/10/2015
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Watanabe, Hiroyuki
• Primary Examiner(s): Zhang, Jue
• Assistant Examiner(s): Novak, Peter M
• Application Number:
  US15/741,546
• Publication Number:
  US 20180198363A1
• Time in Patent Office: 1,366 Days
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02M 1/126 using passive filters
• 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 7/06 using discharge tubes without control electrode or semiconductor devices without control electrode
• CPC Class Codes: H02M 7/125 Avoiding or suppressing excessive transient voltages or currents

Abstract

[Object]

[Solving Means] A discharge device includes a discharge unit and a cut-off detection unit. The discharge unit is configured to discharge a capacitor at a variable discharge current value on the basis of a voltage of a rectified signal obtained by full-wave rectifying an AC voltage input via an input filter including the capacitor. The cut-off detection unit is configured to monitor the voltage of the rectified signal and to detect whether or not a power supply is cut off on the basis of a change of the voltage when the capacitor is discharged by the discharge unit at a specific discharge current value.

Claims

1. A discharge device, comprising:

a discharge unit configured to discharge a capacitor at a variable discharge current value on the basis of a voltage of a rectified signal obtained by full-wave rectifying an AC voltage input via an input filter including the capacitor; and

a cut-off detection unit configured to monitor the voltage of the rectified signal and to detect that a power supply which provides the AC voltage input is not cut off when pulsation of the rectified signal is not detected and the voltage of the rectified signal is greater than a threshold value during discharge of the capacitor by the discharge unit at a specific discharge current value.

2. The discharge device according to claim 1, wherein

the cut-off detection unit includes

a pulsation detection circuit configured to detect whether or not the rectified signal is pulsation by monitoring the voltage, and

a DC voltage monitor circuit configured to monitor a voltage of a rectified signal of non-pulsation in a case where the non-pulsation is detected by the pulsation detection circuit.

3. The discharge device according to claim 2, wherein

the discharge unit is configured to discharge the capacitor at a first discharge current value in a case where the non-pulsation is detected by the pulsation detection circuit.

4. The discharge device according to claim 3, wherein

the discharge unit is configured to discharge the capacitor at a second discharge current value lower than the first discharge current value after the discharge unit discharges the capacitor at the first discharge current value.

5. The discharge device according to claim 4, wherein

the discharge unit is configured to discharge the capacitor at the first discharge current value in a case where it is determined that the voltage of the rectified signal has a value equal to or less than the threshold value by the DC voltage monitor circuit when the capacitor is discharged at the second discharge current value.

6. The discharge device according to claim 4, wherein

the discharge unit is configured to discharge the capacitor at the second discharge current value after a predetermined time elapses from a start of the discharge at the first discharge current value.

7. The discharge device according to claim 1, wherein

the discharge unit includes

a first discharge path having a first resistor, and

a second discharge path having a second resistor having a resistance value different from a resistance value of the first resistor.

8. The discharge device according to claim 7, wherein

the first discharge path is configured to use a charge path capable of charging the discharge device.

9. The discharge device according to claim 1, wherein

the discharge unit includes a discharge path having a variable resistor.

10. The discharge device according to claim 1, wherein

the discharge unit includes

a current source, and

a circuit that variably controls the discharge current value by the current source.

11. A power supply apparatus, comprising:

an input filter including a capacitor;

a converter configured to convert an AC voltage input via the input filter into a DC voltage;

a full wave rectifier unit configured to full-wave rectify the AC voltage input via the input filter;

a discharge unit configured to discharge the capacitor at a variable discharge current value on the basis of a voltage of a rectified signal obtained by the full wave rectifier unit; and

a cut-off detection unit configured to monitor the voltage of the rectified signal and to detect that a power supply which provides the AC voltage input is not cut off when pulsation of the rectified signal is not detected and the voltage of the rectified signal is greater than a threshold value during discharge of the capacitor by the discharge unit at a specific discharge current value.

12. A discharge method, comprising:

monitoring a voltage of a rectified signal obtained by full-wave rectifying an AC voltage input via an input filter including a capacitor;

discharging the capacitor at a specific discharge current value of variable discharge current values on the basis of the voltage of the rectified signal; and

detecting that a power supply which provides the AC voltage input is not cut off when pulsation of the rectified signal is not detected and the voltage of the rectified signal is greater than a threshold value during discharge of the capacitor by the discharge unit at the specific discharge current value.