Control of driver current via low side gates
AssigneeSiemens VDO Automotive Corporation
InventorsJohn C. McCoy, Lou Vierling
Life of this patent
Estimating the term…
Abstract
A fuel injector coil control circuit includes high side and low side gates. The current through the coil is increased while being monitored by low side shunt circuitry. The current continues to increase until a predetermined value is reached. When the predetermined value is reached, the low side gate is switched off and the current begins to decay. The off time of the low side gate is controlled for a predetermined period of time. After the predetermined period of time elapses, the low side gate is switched back on, causing the current to rise again toward the predetermined value.
Claims20
A fuel injector control circuit comprising:
- at least one coil for controlling the operation of an injector;
- at least one switch selectively activating said at least one coil;
- a timing circuit switching said switch on based upon the expiration of a predetermined time.
A method for controlling a fuel injector including the steps of:
- (a) Activating a coil to control a fuel injector;
- (b) Deactivating the coil to control the fuel injector;
- and
- (c) Switching from said step (b) to said step (a) based upon the lapse of a predetermined period.
A fuel injector control circuit comprising:
- at least one coil for controlling the operation of a fuel injector;
- at least one high side gate selectively connecting the at least one coil to a ground, and
- a timing circuit switching a selectively activated one of the at least one high side gate and the at least one low side gate based upon the expiration of a predetermined time and being activated based upon a current through the selectively activated gate reaching a predetermined threshold.
Dependencies are inferred from the claim text.