Abstract: The subject invention provides a digital Storage System such as a Winchester Hard Disk Drive System having a motorized hard disk drive assembly which interacts with a head positioner to read and write data and timing instructions onto a plurality of disks driven by the assembly. The drive system includes a data separation circuit for reconstruction of data recorded on the hard disk. The data separation circuit includes a phase-locked loop system. The phase-locked loop system includes a phase comparison circuit, a voltage controlled oscillator, a control circuit including a capacitor for controlling said oscillator, and a charge pump for pumping up and pumping down the control circuit. Except for the phase comparison circuit, the entire phase-locked loop system is provided on a monolithic integrated chip.

Abstract: Apparatus for automatically regulating the amount of charge applied to an insulating surface. In a first embodiment an electrometer measures the electrostatic potential, or charge, on the insulating surface and generates an output voltage proportional thereto. The output voltage is continuously monitored and compared in a comparison means with a reference potential, the difference therebetween corresponding to an error signal. The error signal is periodically sampled and applied to an analog incremental integrator, the output thereof being coupled to a corona generator power supply, the power supply in turn being coupled to a corona electrode. The voltage applied by the power supply to the corona electrode is of a magnitude to cause the wire to apply sufficient charge to the insulating surface to reduce the error signal to substantially zero. In a second embodiment the output of the comparison means is sampled and delayed and then coupled to the corona generator power supply.