Low-voltage power supply circuit for illumination, illumination device, and low-voltage power supply output method for illumination
First Claim
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1. A low-voltage power supply circuit for supplying a low-voltage power supply for illumination, comprising:
- a rectifier circuit for rectifying an ac power supply;
a power-factor control circuit for controlling rectified output from said rectifier circuit, said power-factor control circuit being composed of a step-down circuit, and moreover, being provided with a current-limiting capability,a switch element that is both driven by the output of said rectifier circuit and the detected output of a power supply current and switched by the control output from said power-factor control circuit;
a step-down transformer that is controlled by the output of said switch element;
a output circuit for both rectifying the output of said transformer and filtering the high-frequency component by means of a passive element; and
a current detection circuit for obtaining the detected output of said power supply current from the output current of said simplified output circuit.
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Abstract
In a low-voltage power supply circuit for illumination that rectifies an ac power supply by means of a rectifier circuit, that controls this rectified output by means of a power-factor control circuit, and that supplies a low-voltage power supply for illumination, the power-factor control circuit is composed of a step-down circuit and is further provided with a current-limiting capability.
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Citations
8 Claims
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1. A low-voltage power supply circuit for supplying a low-voltage power supply for illumination, comprising:
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a rectifier circuit for rectifying an ac power supply; a power-factor control circuit for controlling rectified output from said rectifier circuit, said power-factor control circuit being composed of a step-down circuit, and moreover, being provided with a current-limiting capability, a switch element that is both driven by the output of said rectifier circuit and the detected output of a power supply current and switched by the control output from said power-factor control circuit; a step-down transformer that is controlled by the output of said switch element; a output circuit for both rectifying the output of said transformer and filtering the high-frequency component by means of a passive element; and a current detection circuit for obtaining the detected output of said power supply current from the output current of said simplified output circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification