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Browse Prior Art Database

Velocity Profile Compensator

IP.com Disclosure Number: IPCOM000085124D
Original Publication Date: 1976-Feb-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Fraser, GB: AUTHOR [+2]

Abstract

An article in the IBM Technical Disclosure Bulletin, Vol. 16, No. 12, May 1974, pages 4064 and 4065, entitled "Disk File Track Access Control" by R. D. Commander and D. H. Martin describes how the performance of individual disk file actuator mechanisms can be optimized, to reduce the effect of circuit tolerances which may vary considerably from one actuator to the next.

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Velocity Profile Compensator

An article in the IBM Technical Disclosure Bulletin, Vol. 16, No. 12, May 1974, pages 4064 and 4065, entitled "Disk File Track Access Control" by R. D. Commander and D. H. Martin describes how the performance of individual disk file actuator mechanisms can be optimized, to reduce the effect of circuit tolerances which may vary considerably from one actuator to the next.

A modification to the circuit is shown in Fig. 1, which takes account of temperature changes and supply voltage fluctuations enabling the design tolerance band to be reduced still further. The modification consists of an additional circuit inserted between the output of the counter 10 and the input from the counter 10 to the digital-to-analog converter 8. For the sake of simplicity only these two components of the previously published circuit are reproduced in Fig.
1.

Temperature changes are sensed by a coil 12 mounted in the vicinity of the actuator motor. The resistance Rc is monitored by circuit 13. The supply voltage Vs on line 14 is also monitored by circuit 13. The output from counter 10 which in the previously published article, controlled directly the gain of the digital-to- analog converter 8 is supplied as input lead 15 to the circuit 13. The output lead 16 from circuit 13 now controls the gain of the digital-to-analog converter 8. The function of circuit 13 is thus to provide an output which reflects the input received from counter 10, modified in such a way as to take account of temperature changes and/or variations in supply voltage Vs.

This is achieved by making the output voltage Vout from circuit 13 resp...