Patent ID: 8154266
Filing Date: 2012-04-10
Classification: H02M

Abstract:
1. A bi-directional direct current (DC) power circuit comprising: a signal processing module configured to process voltage drop feedback and output voltage feedback, and output pulse control and directional control signals; a sense resistor coupled to the signal processing module for sensing current, the resistance of the sense resistor being about 15 to 100 mΩ; a pulse-width modulation (PWM) module coupled to the signal processing module, the PWM module configured to output pulse signals in response to the pulse control signals; and a switch rectifying module coupled to the PWM module, the switch rectifying module configured to turn on and off based on the pulse signals from the PWM module, wherein the PWM module includes an oscillator coupled to a bi-directional PWM circuit, and wherein clock signals from the oscillator control the period of pulse signals outputted from the PWM module, wherein the signal processing module includes a current feedback unit, a voltage feedback unit, and a directional control unit, wherein the directional control unit couples to the current feedback unit, the voltage feedback unit and the bi-directional PWM circuit of the PWM module, and the current feedback unit couples to the oscillator of the PWM module; and wherein the current feedback unit includes a current amplifier and first and third comparators, the current amplifier capable of transforming voltage corresponding to the sensed current of the sense resistor and voltage drop between an initial input voltage and the sense resistor, the first comparator operable to output a logic level current comparator signal by comparing signals from the selection circuit and the current from the current feedback unit, and the third comparator operable to output a reverse current comparator signal by comparing the voltage corresponding to the sensed current of the sense resistor and the voltage drop between the initial input voltage and the sense resistor.