Abstract: An apparatus is provided for precharging a filter capacitor to prevent damage to a set of contacts resulting from arcing across the contacts. Included is a coil, a set of contacts, and a battery, such that the contacts and filter capacitor are connected in series and the series connected combination is connected in parallel across the battery. Also included is a switch, and a microprocessor for producing a triggering signal responsive to the closure of the switch. A driving circuit receives the triggering signal and responsively produces a charging signal. A charging circuit receives the charging signal and responsively charges the filter capacitor. Thereafter, the microprocessor produces an energizing signal causing the coil to become energized and the contacts to responsively close. By precharging the filter capacitor before the closure of the contacts, the voltage potential across the contacts is reduced. Therefore, no damage occurs due to arcing across the contacts.

Abstract: An apparatus is provided for controllably connecting and disconnecting a piezoelectric actuator to and from an energy source to effect the displacement of a piezoelectric actuator for a fuel injector. Precise control of the timing and duration of the piezoelectric actuator is necessary to ensure that a proper quantity of fuel is delivered to each cylinder of an internal combustion engine. A charging and discharging means monitors the voltage level of the piezoelectric actuator, and the charging and discharging current of the piezoelectric actuator. Further, a smoothing means aids in leveling the charging and discharging current to better approximate a constant current to control the piezoelectric actuator providing a precise quantity of fuel to be delivered.

Abstract: A motor speed control system for a vehicle is provided. The control system includes an electric motor connected to a power coupling element for delivering electrical energy to the motor in response to a control signal. A sensor produces a current signal in response to the magnitude of the current flowing through the motor. An accelerator pedal produces a command signal in response to a desired vehicle speed. A microprocessor receives the command signal and responsively delivers a pulse width modulated control signal to the power coupling element. The control signal has a duty cycle in a range between a minimum and predefined value. Additionally, the microprocessor receives the current signal and increases the duty cycle of the control signal by a predetermined amount beyond the predefined value in response to the received current signal.

Abstract: Automated charging systems for vehicles having rechargeable batteries are in common use today. Such systems typically have exposed contacts or the need for additional circuitry to move the contacts. The subject system includes circuitry which allows the charge receiving member to be only connected to the battery during charging. The charging system produces a charging signal in response to a low battery. A microprocessor receives the charging signal and responsively produces a "pulse" signal. A second transistor switch receives the "pulse" signal and responsively energizes a charging contactor coil. In response to the charging contactor coil being energized, contacts controllably block power from the battery to the motor and pass power from the receiving member to the battery.