Patent ID: 7230488
Filing Date: 2007-06-12
Classification: H02M

Abstract:
1. An amplifying circuit comprising: an NPN-type bipolar transistor having an emitter connected to one end of a secondary winding of a transformer with a primary winding and the secondary winding, a collector connected to a positive pole of a DC power source; a first resistor connected between the collector of said NPN-type bipolar transistor and a base of said NPN-type bipolar transistor; a PNP-type bipolar transistor having an emitter connected to the emitter of said NPN-type bipolar transistor, a collector connected to a negative pole of the DC power source; a second resistor connected between the collector of said PNP-type bipolar transistor and a base of said PNP-type bipolar transistor; first and second voltage drop elements connected in series between the base of said NPN-type bipolar transistor and the base of said PNP-type bipolar transistor to generate voltage drops corresponding to a base-emitter voltage of said NPN-type bipolar transistor and an emitter-base voltage of said PNP-type bipolar transistor; a first capacitor connected between the base of said NPN-type bipolar transistor and the other end of the secondary winding of the transformer; a second capacitor connected between the base of said PNP-type bipolar transistor and the other end of the secondary winding of the transformer; and a current supply capacitor having one end connected to the other end of the secondary winding of the transformer, wherein current flowing into the primary winding of the transformer is amplified and the amplified current is output via said current supply capacitor.