Browse Prior Art Database

Disk File Current Generator

IP.com Disclosure Number: IPCOM000055711D
Original Publication Date: 1980-Aug-01
Included in the Prior Art Database: 2005-Feb-13

Publishing Venue

IBM

Related People

Authors:
Marshall, SE [+details]

Abstract

A disk file write current generator circuit which compensates for temperature-induced variation in device B is shown in the figure. The object of the circuit is to generate a constant current I at the disk file write head 1. A precision voltage source and high stability discrete resistor form the basic components for the circuit design. A constant voltage is maintained at the emitter of transistor T(1) by feedback from an operational amplifier 2 which continuously compares the voltage at a node A in the emitter path of transistor T(1) with a constant voltage from constant voltage source 3. Any variation in emitter voltage results in a change in output voltage from the operational amplifier 2.