Patent ID: 7684219

Claim:
A multiplexed DC voltage regulation output circuit, comprising: a first output circuit configured for outputting low voltage; a second output circuit configured for outputting high voltage; a transformer configured for outputting voltages to the first output circuit and the second output circuit; a power control chip; a feedback circuit configured for feeding composite signals of the first output circuit and the second output circuit to the power control chip, the power control chip configured for adjusting the output voltages of the transformer by changing an impulse width of voltages transmitted from the power control chip into the transformer in accordance with the composite signals; and a control circuit configured for controlling the output voltage of the second output circuit down to a normal high voltage when the output voltage of the second output circuit is higher than the normal high voltage; wherein the control circuit comprises: a first resistor; a second resistor; a third resistor; a diode comprising a positive electrode and a negative electrode; a high voltage output port for outputting high voltage; a first adjustable precision shunt regulator comprising a reference electrode, a negative electrode, and a positive electrode, the reference electrode connected to the high voltage output port via the second resistor and grounded via the third resistor, the negative electrode of the first adjustable precision shunt regulator connected to the transformer sequentially via the first resistor, the positive electrode of the diode, and the negative electrode of the diode, and the positive electrode of the first adjustable precision shunt regulator being grounded; a resistor-capacitor (RC) shunt circuit with one terminal connected to the positive electrode of the diode and the other terminal being grounded; and an n-channel metal oxide semiconductor field-effect transistor comprising a gate electrode connected to the positive electrode of the first adjustable precision shunt regulator, a source electrode connected to the high voltage output port, and a drain electrode connected to the output of the second output circuit.