Patent attributes
In a DC power supply or a battery charger, plural output filter capacitors remain highly charged after the load is removed and the converter is turned off. A transistor connected across the capacitors is non-conductive during normal power supply operation and a bleed resistor connecting the transistor to the output capacitors is not in the circuit during normal power supply operation. When the power supply is turned off and the load is removed, the transistor is automatically rendered conductive with the removal of the pulsed output of the power supply's power transformer to the transistor, with the energy stored in the capacitors safely and quickly discharged to the output return via the bleed resistor which is placed in circuit by the conducting transistor.