Overvoltage protection circuit and power supply apparatus
AssigneeYokogawa Electric Corporation
InventorsMasatoshi Kutsukake, Akira Moriyama
Life of this patent
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Abstract
An overvoltage protection circuit includes an error amplifier, which outputs a first command voltage for bringing the output voltage of a converter closer to a first set voltage, and an overvoltage detection circuit, which outputs a second command voltage for bringing the output voltage of the converter closer to a second set voltage that is higher than the first set voltage. The overvoltage protection circuit controls the converter based on the first command voltage and the second command voltage. Noise immunity can be guaranteed even when an overvoltage detection level is set lower than the level of disturbance noise.
Claims8
An overvoltage protection circuit comprising:
- an error amplifier configured to input an output voltage of a converter and a first set voltage, and output a first command voltage to a pulse width modulation (PWM) control circuit for keeping the output voltage of the converter closer to the first set voltage than a second set voltage;
- and
- an overvoltage detection circuit configured to input the output voltage of the converter and the second set voltage higher than the first set voltage, and output a second command voltage to the PWM control circuit for keeping the output voltage of the converter closer to the second set voltage than the first set voltage;
- wherein the PWM control circuit controls the converter based on the first command voltage and the second command voltage.
Dependencies are inferred from the claim text.