| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a power switch unit for controlling electrical connection and disconnection of the primary current of an ignition coil for an internal combustion engine. Ž<P>SOLUTION: This power switch unit controls electrical connection and disconnection of the primary current, which flows in a primary coil of an ignition coil for internal combustion engine, to generate a high voltage in a secondary coil in response to an ignition signal output from an engine control unit. The power switch unit is structured of one chip as a unit of a power transistor, which is formed of an insulated gate bipolar transistor (IGBT) connected in series to the primary coil, and a current limiting circuit, which is inserted between a base electrode and an emitter electrode of the power transistor. Since the power transistor formed of the insulated gate bipolar transistor (IGBT) has a characteristic that electrical resistance is low, a large current can be made to flow in the primary coil of the ignition coil for the internal combustion engine. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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