Fast response two coil solenoid driver

Claim 1

A fuel control system for an internal combustion engine comprising: at least one fuel injector adapted to receive fuel and for injecting a determinable quantity of fuel to a cylinder of the engine, including metering chamber means for storing the determinable quantity of the received fuel prior to the injection of the fuel into the cylinder and solenoid means operatively situated relative to said metering chamber means for selectively permitting, upon activation, the received fuel to flow therein, said solenoid means including a first or pull-in coil and a second or hold coil that are magnetically coupled to each other; generator means responsive to at least one engine operating parameter for generating a plurality of pulse train signals, phased relative to one another and synchronized to the combustion process within the engine for energizing of said solenoid means for controlling the activation time of said solenoid means and for controlling the duration of fuel flow to said metering means; source means, including a battery, for providing a ready source of electrical energy; boost means, responsive to a first pulsed signal of said plurality of signals for generating a first voltage greater than the voltage of said source means comprising: a boost coil connected to said source means; first switch means, including a first transistor, connected to said boost coil, for transferring a first quantity of electrical energy from said source means to said boost coil in response to said first pulsed signal; first and second diodes having their cathode terminals connected in common and having the anode of said first diode connected to said source means and having the anode of said second diode connected to said boost coil at the junction of said boost coil and said first switch means; current limiting means, including a first resistor connected to said first switch means for limiting the current flow therethrough; second switch means, one associated with each of said at least one fuel injector, responsive to a second pulsed signal of said plurality of pulsed train signals and connected to one terminal of said pull-in coil for permitting current to flow through said pull-in coil in timed relationship with the generation of the first pulsed signal and wherein the other terminal of said pull-in coil is connected to the anode of said first diode; a third diode, one associated with each of said at least one fuel injector having its anode connected to said one terminal of said pull-in coil, and its cathode connected to a first terminals of said hold coil; third switch means, one associated with each said at least one fuel injector and responsive to a third pulsed signal of said plurality of pulsed train signals and connected to a second terminal of said hold coil for activating said hold coil to maintain said solenoid means in an activated state thereby permitting continued fuel flow into said metering chamber means.