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Elimination of Feedthrough in Transducers

IP.com Disclosure Number: IPCOM000092045D
Original Publication Date: 1968-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Rodriquez, JA: AUTHOR

Abstract

Optimum reduction of feedthrough signals between write and read elements of a multiple head magnetic transducer is realized. A shielding magnetic field in proportion to a summation current, derived from the input signals to all of the write heads is provided.

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Elimination of Feedthrough in Transducers

Optimum reduction of feedthrough signals between write and read elements of a multiple head magnetic transducer is realized. A shielding magnetic field in proportion to a summation current, derived from the input signals to all of the write heads is provided.

The magnetic transducer includes a multiplicity of write heads such as 16 and
18. Each is energized by a separate write driver circuit such as 26, the latter responding to input signals at 27. The transducer also includes a multiplicity of read heads such as 20 and 22. The latter are separated from 16 and 18 by magnetic shield 14 composed of laminated, high-permeability magnetic material for reducing write head-to-read head magnetic coupling. Winding 42 is provided to induce compensating flux into 14 in proportion to write head current.

The input signal to 26 is inverted through 28 and amplified by transistor 45. A similar inverter and amplifier arrangement is associated with each write driver with only amplifier transistors 46 and 49 being shown. These transistor stages are adjusted via resistors 50, 51, and 52 to provide a compensating current to be introduced ultimately to 42 for the purpose of cancelling feedthrough magnetic flux being generated by the associated write head. The outputs of 45, 47, and 49 are summed as the input to transistor 55, which introduces to 42 a total compensation current adjusted by resistor 56.

By this arrangement, the total current and...