POWER SUPPLY DEVICE

• US 20130294122A1
• Filed: 07/01/2013
• Published: 11/07/2013
• Est. Priority Date: 01/20/2011
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Corporation
• Inventors: TAKAHASHI, Hajime
• Granted Patent: US 9,099,931 B2
• Time in Patent Office: Days
• US Class Current: 363/53
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: G06F 1/30 Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations for resetting only G06F1/24
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H02M 7/217 using semiconductor devices only

Abstract

A power supply device includes a converter, a rectifier circuit, a voltage cycle detection circuit, and a power supply cutoff signal output unit. The converter converts an AC voltage inputted from an external power supply to a DC voltage and outputs the DC voltage. The rectifier circuit rectifies the AC voltage inputted from the external power supply and outputs a rectified waveform voltage. The voltage cycle detection circuit detects a voltage cycle in which the rectified waveform voltage reaches a predetermined threshold value and, when the voltage cycle is detected to be longer than a predetermined cycle, outputs a voltage cycle abnormality signal. The power supply cutoff signal output unit outputs a power supply cutoff signal when the voltage cycle abnormality signal is inputted.

Claims

1. A power supply device comprising:

a converter which converts an AC voltage inputted from an external power supply to a DC voltage and outputs the DC voltage;

a rectifier circuit which rectifies the AC voltage inputted from the external power supply and outputs a rectified waveform voltage;

a voltage cycle detection circuit which detects a voltage cycle in which the rectified waveform voltage reaches a predetermined threshold value and, when the voltage cycle is detected to be longer than a predetermined cycle, outputs a voltage cycle abnormality signal; and

power supply cutoff signal output means for outputting a power supply cutoff signal when the voltage cycle abnormality signal is inputted.

2. The power supply device according to claim 1, wherein the rectifier circuit is a full-wave rectifier circuit.

3. The power supply device according to claim 2, wherein

the voltage cycle detection circuit includes

a first voltage detector which outputs a first signal when a full-wave rectified waveform voltage of the full-wave rectifier circuit is detected to be not less than the predetermined threshold value,

a first time period detector which outputs a first confirmation signal when the first signal continues to be outputted for a predetermined first time period or longer,

a second voltage detector which outputs a second signal when the full-wave rectified waveform voltage of the full-wave rectifier circuit is detected to be less than the predetermined threshold value, and

a second time period detector which outputs a second confirmation signal when the second signal continues to be outputted for a predetermined second time period or longer and

outputs the voltage cycle abnormality signal when one of the first confirmation signal and the second confirmation signal is inputted.

4. The power supply device according to claim 3, wherein

the power supply cutoff signal output means includes

signal retention means for retaining an output of the power supply cutoff signal at least during a third time period starting from when the full-wave rectified waveform voltage is detected to be less than the predetermined threshold value.