Power supply device
First Claim
1. A power supply device comprising:
- a resistor to limit an electric current supplied from an alternating-current power supply;
a switch that is connected in parallel with the resistor;
a rectifier circuit that is connected to a subsequent stage of the resistor and the switch to rectify an alternating-current voltage of the alternating-current power supply;
a booster circuit to boost a direct-current voltage rectified by the rectifier circuit;
a direct-current-voltage detector to detect a direct-current voltage output from the booster circuit;
an alternating-current-voltage detector to detect an alternating-current voltage of the alternating-current power supply;
a protection setter to calculate a first protection voltage on a basis of a boosting level by the booster circuit, calculate a second protection voltage on a basis of the alternating-current voltage detected by the alternating-current-voltage detector, compare the first protection voltage with the second protection voltage, and set either one of the first protection voltage and the second protection voltage as a protection voltage; and
a controller to open the switch when the direct-current voltage falls below the protection voltage set by the protection setter and stop boosting performed by the booster circuit, whereinif the direct-current voltage falls below the protection voltage immediately after supply of an alternating-current voltage from the alternating-current power supply is stopped, the protection setter holds the protection voltage without changing the protection voltage and, after supply of the alternating-current voltage from the alternating-current power supply is started and a second transition period, which is a transition period of the direct-current voltage, passes, the protection setter changes setting of the protection voltage from the first protection voltage to the second protection voltage.
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Accused Products
Abstract
A power supply device includes a resistor that limits an electric current supplied from an AC power supply, a switching unit that is connected in parallel with the resistor, a rectifier circuit unit that is connected to a subsequent stage of the resistor and the switching unit and rectifies an AC voltage of the AC power supply, a booster circuit unit, a DC-voltage detection unit that detects a DC voltage output from the booster circuit unit, an AC voltage detection unit, a protection setting unit that compares a first protection voltage calculated on the basis of the boosting level by the booster circuit unit with a second protection voltage calculated based on the AC voltage detected by the AC-voltage detection unit and sets either one as a protection voltage, and a control unit that opens the switching unit when the DC voltage falls below the protection voltage and stops boosting.
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Citations
8 Claims
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1. A power supply device comprising:
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a resistor to limit an electric current supplied from an alternating-current power supply; a switch that is connected in parallel with the resistor; a rectifier circuit that is connected to a subsequent stage of the resistor and the switch to rectify an alternating-current voltage of the alternating-current power supply; a booster circuit to boost a direct-current voltage rectified by the rectifier circuit; a direct-current-voltage detector to detect a direct-current voltage output from the booster circuit; an alternating-current-voltage detector to detect an alternating-current voltage of the alternating-current power supply; a protection setter to calculate a first protection voltage on a basis of a boosting level by the booster circuit, calculate a second protection voltage on a basis of the alternating-current voltage detected by the alternating-current-voltage detector, compare the first protection voltage with the second protection voltage, and set either one of the first protection voltage and the second protection voltage as a protection voltage; and a controller to open the switch when the direct-current voltage falls below the protection voltage set by the protection setter and stop boosting performed by the booster circuit, wherein if the direct-current voltage falls below the protection voltage immediately after supply of an alternating-current voltage from the alternating-current power supply is stopped, the protection setter holds the protection voltage without changing the protection voltage and, after supply of the alternating-current voltage from the alternating-current power supply is started and a second transition period, which is a transition period of the direct-current voltage, passes, the protection setter changes setting of the protection voltage from the first protection voltage to the second protection voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification