TEMPERATURE COMPENSATION IN OUTPUT FEEDBACK OF A FLYBACK POWER CONVERTER
First Claim
1. A secondary circuit of a flyback power converter including a capacitor connected between an output end and a ground end to supply an output current, and a secondary coil of a transformer to provide a secondary current for charging the capacitor, the secondary circuit comprising:
- a resistor network connected in a path of the output current to generate a voltage according to the output current; and
a bipolar junction transistor having a base connected to the resistor network to receive the voltage and providing a collector signal for output feedback;
wherein the resistor network has a resistance varying with temperature to compensate for a temperature effect of a base-emitter voltage of the bipolar junction transistor on the output current.
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Accused Products
Abstract
A secondary circuit of a flyback power converter has a resistor network to monitor the output current of the flyback power converter, so as to generate a voltage to apply to a base of a bipolar junction transistor to thereby provide a collector signal for output feedback. The resistor network has a temperature-dependent resistance to compensate the temperature dependence of the base-emitter voltage imparted to the output current and thereby stable the output current.
8 Citations
3 Claims
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1. A secondary circuit of a flyback power converter including a capacitor connected between an output end and a ground end to supply an output current, and a secondary coil of a transformer to provide a secondary current for charging the capacitor, the secondary circuit comprising:
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a resistor network connected in a path of the output current to generate a voltage according to the output current; and a bipolar junction transistor having a base connected to the resistor network to receive the voltage and providing a collector signal for output feedback; wherein the resistor network has a resistance varying with temperature to compensate for a temperature effect of a base-emitter voltage of the bipolar junction transistor on the output current. - View Dependent Claims (2)
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3. A method for stabilizing an output current of a flyback power converter including a capacitor connected between an output end and a ground end to supply the output current, and a secondary coil of a transformer to provide a secondary current for charging the capacitor, the method comprising the steps of:
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generating a voltage by the output current flowing through a resistor network; and applying the voltage to a base of a bipolar junction transistor to provide a collector signal for output feedback; wherein the resistor network has a resistance varying with temperature to compensate for a temperature effect of a base-emitter voltage of the bipolar junction transistor on the output current.
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Specification