Patent ID: 8294295

Claim:
A power supply method with parallel-connected batteries; characterized in that at least two power supply branches being connected parallelly; each power supply branch including a battery set comprising of batteries providing a low voltage, a step-up circuit, implemented as a push-pull circuit for transforming the low voltage into a high voltage, including two field effective transistors, VT 1 and VT 2 , a transformer, four switch diodes, a filter inductance, and a capacitor EC 1 ; a step-down circuit, implemented as a BUCK circuit for transforming said high voltage to a desired power-supply voltage, including a switch diode VD 5 , a filed effective transistor VT 3 , a capacitor EC 2 , an inductance, and an individual control unit of a digital signal processing unit DSP, connects to gate electrodes of VT 1 , VT 2 , and VT 3 , to anodes of EC 1 and CE 2 , and to two ends of a current limiting resistance, respectively; an output of said power supply branch being serially connected with a diode for preventing another power supply branch from a reverse current; a cathode of said out put being serially connected with said current limiting resistance for balancing currents, wherein said digital signal processing unit DSP controls alternate conductions of said two field effective transistors VT 1 and VT 2 ; based on a feedback voltage of said capacitors EC 1 and EC 2 and a feedback current of said current limiting resistance, a space ratio of said field effective transistor VT 3 is adjusted for reducing said high voltage to the desired power-supply voltage.