Power supply device and illumination device for vehicle using same
First Claim
1. A power supply device, comprising:
- a DC power supply circuit configured to output DC power; and
a ground-fault determining circuit configured to determine presence or absence of a ground fault at a post-stage of the DC power supply circuit,the ground-fault determining circuit comprising;
a capacitor, of which an end being connected with ground;
a diode including an anode and a cathode, the anode being connected with another end of the capacitor, the cathode being connected with an output end on a high voltage side of the DC power supply circuit;
a determining portion configured to determine the presence or absence of the ground fault based on a voltage across the capacitor; and
a constant voltage source configured to charge the capacitor with a prescribed charging voltage,the prescribed charging voltage being lower than an output voltage from the DC power supply circuit in a state where the ground fault is absent and power supplying is normally performed from the DC power supply circuit to a load, andthe determining portion being configured to determine the presence of the ground fault when the voltage across the capacitor falls below a prescribed determination reference voltage that is lower than the prescribed charging voltage.
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Accused Products
Abstract
A power supply device includes a DC power supply circuit configured to output DC power, and a ground-fault determining circuit configured to determine presence or absence of a ground fault at a post-stage of the DC power supply circuit. The ground-fault determining circuit includes a capacitor having an end that is connected with ground, and a diode including an anode and a cathode. The anode is connected with another end of the capacitor, and the cathode is connected with an output end on a high voltage side of the DC power supply circuit. The ground-fault determining circuit further includes a constant voltage source configured to charge the capacitor with a prescribed charging voltage, and a comparator as a determining portion configured to determine presence of the ground fault when a voltage across the capacitor falls below a prescribed determination reference voltage lower than the prescribed charging voltage.
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Citations
12 Claims
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1. A power supply device, comprising:
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a DC power supply circuit configured to output DC power; and a ground-fault determining circuit configured to determine presence or absence of a ground fault at a post-stage of the DC power supply circuit, the ground-fault determining circuit comprising; a capacitor, of which an end being connected with ground; a diode including an anode and a cathode, the anode being connected with another end of the capacitor, the cathode being connected with an output end on a high voltage side of the DC power supply circuit; a determining portion configured to determine the presence or absence of the ground fault based on a voltage across the capacitor; and a constant voltage source configured to charge the capacitor with a prescribed charging voltage, the prescribed charging voltage being lower than an output voltage from the DC power supply circuit in a state where the ground fault is absent and power supplying is normally performed from the DC power supply circuit to a load, and the determining portion being configured to determine the presence of the ground fault when the voltage across the capacitor falls below a prescribed determination reference voltage that is lower than the prescribed charging voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification