Abstract: A grabber mechanism for use in a badge rader having a pivoted lever bar with a solenoid attached to one end and a grabber foot assembly attached to the other. When the solenoid is energized, the lever bar is pivoted such that the grabber foot assembly is moved away from a fixed partition which defines a throat in the badge reader, allowing a card to be inserted into the throat. When the solenoid is de-energized, the grabber foot assembly is urged by a spring into contact with the card, trapping the card between a rubber foot of the grabber assembly and the fixed partition sot that the card may be read by the badge reader.

Abstract: A solenoid driver circuit having a power supply, a capacitor connected to the power supply, a current pump which oscillates between the on and off condition to charge the capacitor from the power supply, a voltage limiting circuit which limits the voltage of the charge on the capacitor, a solenoid connected to the capacitor and, a solenoid switch which, when activated, closes such that the charged capacitor discharges through the solenoid. After the capacitor is discharged, holding current is supplied to the solenoid from the power supply. The current pump is held off while the solenoid switch is closed so that the current pump will not attempt to charge the capacitor while holding current is being supplied to the solenoid.

Abstract: A digital controller includes a digital feedback circuit for use in generating a pulse-width modulated control signal. The signal is derived from binary signals representing a standard pulse-width signal for the rated output of the power supply plus a correction pulse-width signal reflecting the change in the output level of the power supply. Logic circuits alter the correction pulse-width signals to provide a balancing correction. Soft start operation of the power supply together with a selection of operating clock frequencies are also provided.

Abstract: A circuit provides means for driving a load under control of a plurality of signals including a drive timing signal which is given a maximum permissible duration by the circuit to prevent damage to the load, an operating signal, and an inhibit signal which prevents operation in case of excessively low power supply voltage. A power supply of opposite polarity is connected to the load so that the load rapidly dissipates its energy into said power supply at the time of turn-off of the drive circuit.