Patent ID: 6151223
Filing Date: 2000-11-21
Classification: H02M

Abstract:
A self-excited DC-DC converter comprising:a first transistor for switching an input DC voltage to produce an output voltage whose voltage value is down converted from the input DC voltage;a primary winding one end of which is connected to a collector of the first transistor;a diode whose cathode is connected to a connection point of the first transistor and the primary winding and whose anode is connected to the ground;a capacitor connected between the other end of the primary winding and the ground;a feedback winding magnetically coupled to the primary winding and connected between a base and an emitter of the first transistor; anda second transistor Provided between the base and emitter of the first transistor for bypassing a base current of the first transistor in such a way that the amount of bypassing the base current is regulated in response to a value of the output voltage;wherein each of the first and second transistors is a PNP transistor.