PURPOSE: To reduce control power and drive power by providing a tap in a primary winding of a main transformer so as to connect a power supply end of a control/drive circuit to the tap.
CONSTITUTION: When a base current is allowed to flow in a transistor 3, voltage is induced in a tap of a primary winding of a main transformer 4 by flowing a collector current. Control power and drive power are accumulated as energy in the main transformer 4 to generate no loss. In the case of supplying a current to a base of the transistor 3, a base drive current, flowing through the tap, is effective for an energy transfer similarly to the collector current of the transistor 3 relating to the main transformer 4, and the base drive current is prevented from being consumed as heat. In the case of turning off the transistor 3, a collector current of a transistor 11 acts only for disappearance of minority carriers of the transistor 3 with a very short simultaneous on-time of a flow through a transistor 10.
IKEGAMI TSUNEO
IKEGAMI TSUNEO
RUBYCON CORP
MICRON KIKI KK
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