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US 6,672,295 B2Granted
Vehicle-mounted ignitor
AssigneeHitachi, Ltd.
InventorsYasuhiko Kohno, Junpei Uruno, Mutsuhiro Mori
Life of this patent
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Abstract
A circuit for supplying an oscillation suppress current is provided between a collector terminal and gate electrode of a main IGBT. The current supply circuit comprises a resistor and a diode which are connected in series. A bypass MOSFET is connected between the series connection and the emitter terminal. No semiconductor element having different temperature characteristics is provided in the current supply circuit.
Claims4
A vehicle-mounted ignitor comprising:
- a primary coil of an ignition coil and an insulated gate type semiconductor device which are connected in series with a direct current source;
- an ignition plug connected to a secondary coil of the ignition coil, to which a higher voltage generated across the secondary coil by switching of said semiconductor device is applied;
- a current restricting circuit for restricting a main current flowing through said semiconductor device to a predetermined value or less by controlling the potential on a control electrode of said semiconductor device;
- and
- a current supply circuit for supplying said control electrode with a current from one of a pair of main terminals of said semiconductor device, having a higher potential,
- wherein said current supply circuit comprises a series circuit of two resistors which are connected in a direction toward said control electrode from said main terminal having a higher potential;
- and a constant voltage element for restricting the potential on the series connection to a predetermined value.
4 more elements
Dependencies are inferred from the claim text.