Patent ID: 8049444

Claim:
A soft-start circuit comprising: a dc power source; a capacitor; a switch; and a regeneration brake circuit directly connected to the dc power source and configured to absorb a return current, comprising a resistor, a diode, and a transistor, wherein a first end of the resistor is connected to a positive pole of the dc power source, a second end of the resistor is connected to a negative pole of the dc power source via the transistor, a positive pole of the diode is connected to the second end of the resistor, a negative pole of the diode is connected to the positive pole of the dc power source via the switch, one end of the capacitor is connected to the negative pole of the diode, the other end of the capacitor is connected to the transistor, one end of the switch is connected to the resistor, and the other end of the switch is connected to the negative pole of the diode, whereby when the switch turns off, the dc power source charges the capacitor via the resistor and the diode of the regeneration brake circuit, and when the switch turns on, the return current turns the transistor on, and the resistor absorbs the return current.