EARTH LEAKAGE CIRCUIT BREAKER AND IMAGE FORMING APPARATUS

• US 20140146424A1
• Filed: 11/25/2013
• Published: 05/29/2014
• Est. Priority Date: 11/29/2012
• Status: Active Grant

• Current Assignee: KYOCERA Document Solutions, Inc. (Kyocera Corporation)
• Original Assignee: KYOCERA Document Solutions, Inc. (Kyocera Corporation)
• Inventors: Sueishi, Naoki
• Granted Patent: US 9,013,841 B2
• Time in Patent Office: Days
• US Class Current: 361/49
• CPC Class Codes: G03G 15/55 Self-diagnostics; Malfunction or lifetime display
• CPC Class Codes: H02H 1/06 Arrangements for supplying operative power power supply arrangements in general G05F, H02M
• CPC Class Codes: H02H 3/162 for ac systems
• CPC Class Codes: H02H 3/33 using summation current transformers H02H3/347 takes precedence
• CPC Class Codes: H02M 1/0006 Arrangements for supplying an adequate voltage to the control circuit of converters
• CPC Class Codes: H02M 1/0048 Circuits or arrangements for reducing losses using snubbers H02M1/34
• CPC Class Codes: H02M 7/06 using discharge tubes without control electrode or semiconductor devices without control electrode
• 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

An earth leakage circuit breaker includes an earth leakage detector, a rectifier, a switching part, and a controller. The switching part is installed on an electric circuit between an alternating current (AC) power supply and the rectifier, and switches between supply and interruption of the power from the AC power supply. The earth leakage detector is installed between the AC power supply and a load. The rectifier rectifies the AC power into direct current (DC) power. The controller causes the rectifier to perform half-wave rectification until earth leakage is detected by the earth leakage detector, and causes the rectifier to perform full-wave rectification when the earth leakage is detected by the earth leakage detector.

Claims

1. An earth leakage circuit breaker comprising:

an earth leakage detector that is installed on an electric circuit between an alternating current (AC) power supply and a load, and detects earth leakage;

a rectifier that switches between a full-wave rectification method and a rectification method other than the full-wave rectification method, and rectifies AC power supplied from the AC power supply to generate direct current (DC) power;

a switching part that is installed on an electric circuit between the AC power supply and the rectifier, and switches between supply and interruption of the power from the AC power supply; and

a controller that is driven by the DC power generated by the rectifier, and causes the switching part to interrupt the power from the AC power supply when the earth leakage is detected by the earth leakage detector,

wherein the controller causes the rectifier to be operated according to the rectification method other than the full-wave rectification method until the earth leakage is detected by the earth leakage detector, and causes the rectifier to be operated according to the full-wave rectification method when the earth leakage is detected by the earth leakage detector.

2. The earth leakage circuit breaker according to claim 1, wherein:

the rectifier has a bridge full-wave rectifier circuit made up of four diodes, and one of the four diodes is connected in series to a switch element that is subjected to switching control by the controller; and

the controller puts the switch element into an off state until the earth leakage is detected by the earth leakage detector, and puts the switch element into an on state when the earth leakage is detected by the earth leakage detector.

3. The earth leakage circuit breaker according to claim 1, wherein the controller is driven by the DC power based on half-wave rectification output from the rectifier until the earth leakage is detected by the earth leakage detector, and is driven by the DC power based on full-wave rectification output from the rectifier when the earth leakage is detected by the earth leakage detector.

4. The earth leakage circuit breaker according to claim 1, wherein the earth leakage detector is a zero-phase current transformer.

5. The earth leakage circuit breaker according to claim 1, wherein:

the rectifier is configured so that the rectification method other than the full-wave rectification method is used as quarter-wave rectification; and

the controller is driven by the DC power based on quarter-wave rectification output from the rectifier until the earth leakage is detected by the earth leakage detector.

6. An image forming apparatus comprising:

the earth leakage circuit breaker according to claim 1;

an image forming unit that forms an image on a recording medium based on image data and

a fixing unit that performs a fixing operation on the recording medium on which the image is formed by the image forming unit.