CONTROL CIRCUIT OF POWER SUPPLY SYSTEM
First Claim
1. A control circuit of a power supply system converting a rectified AC input voltage to a DC output voltage comprising:
- an error signal producing unit detecting the DC output voltage and outputting a signal into which the difference voltage between the detected DC output voltage and a reference voltage is amplified;
a phase compensating unit producing an error signal in cooperation with the error signal producing unit; and
an input voltage detecting unit detecting the AC input voltage and outputting a control signal with the level thereof corresponding to the magnitude of the detected AC input voltage to change the gain in the error signal producing unit by the outputted control signal.
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Accused Products
Abstract
Aspects of the invention provide an error amplifier that can compare a feedback voltage of an output voltage with a reference voltage to produce a resulting error signal in cooperation with a phase compensating circuit. In some aspects of the invention, an AC detecting circuit makes a decision as to whether a detected input voltage signal is that of a 100 Vac system or that of a 200 Vac system to change the gain of the error amplifier according to the result of the decision. When the voltage signal Vis is lower than the threshold voltage established beforehand, for making the transient response speed of the phase compensating circuit faster, the AC detecting circuit increases the gain of the error amplifier. When the voltage signal is higher than the threshold voltage established beforehand, for making a power factor higher, the AC detecting circuit decreases the gain of the error amplifier.
12 Citations
7 Claims
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1. A control circuit of a power supply system converting a rectified AC input voltage to a DC output voltage comprising:
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an error signal producing unit detecting the DC output voltage and outputting a signal into which the difference voltage between the detected DC output voltage and a reference voltage is amplified; a phase compensating unit producing an error signal in cooperation with the error signal producing unit; and an input voltage detecting unit detecting the AC input voltage and outputting a control signal with the level thereof corresponding to the magnitude of the detected AC input voltage to change the gain in the error signal producing unit by the outputted control signal. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification