CPC H05B 45/345 (2020.01) [H02M 7/06 (2013.01); H05B 45/375 (2020.01)] | 8 Claims |
1. A BUCK topological circuit for power supply, comprising:
a rectification circuit, connected to input terminals, a first output terminal, and an earth wire and configured to convert an alternating-current signal at the input terminals to a direct-current signal and transmit the direct-current signal to the first output terminal;
a first filter energy-storage circuit, connected to the first output terminal and the earth wire and configured to filter a signal at the first output terminal and store electric energy;
a step-down constant-current driver chip, having an input terminal connected to the first output terminal so that a voltage at the input terminal is consistent with a bus voltage, a drain electrode connected to a first node and a current sampling terminal connected to a second node so that the step-down constant-current driver chip responses to the signal at the first output terminal to work, wherein the step-down constant-current driver chip does not require an external power supply capacitor;
an output current setting circuit, connected to the second node and the earth wire and configured to set an output current;
a freewheeling circuit, connected to the first output terminal and the first node;
a transformer, connected to the first node and a second output terminal and configured to convert a voltage between the first output terminal and the first node to an output voltage; and
a second filter energy-storage circuit, connected to the first output terminal and the second output terminal and configured to filter the signal at the first output terminal and store electric energy.
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