Patent ID: 9715204
Date: 2017-07-25
CPC Classifications: G03G,H02M,Y02B

Claim:
1. A discharge circuit unit that is connectable to an input line of alternating current (AC) power and discharges a first capacitor, the discharge circuit unit comprising: a discharge circuit that includes a first resistance unit connected in series with a second resistance unit including a first and a second switch having sources that are interconnected to form a first node and that are turned on and off in response to a discharge control signal generated when an input of the AC power is interrupted so as to discharge first capacitor; and a detection circuit that includes a third resistance unit connected in series with a fourth resistance unit including a third and a fourth switch that are transistors and turned on and off by the input of the AC power and the interruption of the AC power so as to generate the discharge control signal from emitters of the third and fourth switches when the input of the AC power is interrupted, a second capacitor is connected between the base of the third switch and the first node, a fifth resistor connected between the emitter and the base of the third switch, a sixth resistor connected between the emitter and the base of the fourth switch, a third capacitor connected between the base of the fourth switch and the first node, a seventh resistor connected in parallel to the second capacitor, and an eighth resistor connected in parallel to the third capacitor, and wherein each of the first to fourth resistance units includes at least one first resistor, second resistor, third resistor and fourth resistor respectively; wherein the detection circuit is configured so that: collectors of the third and the fourth switch are interconnected and connected to the first node; and the discharge control signal is output from emitters of the third and fourth switches.