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Integrated D/A Converter Automatic/ Manual Control Circuitry

IP.com Disclosure Number: IPCOM000048240D
Original Publication Date: 1982-Jan-01
Included in the Prior Art Database: 2005-Feb-08
Document File: 2 page(s) / 40K

Publishing Venue

IBM

Related People

Laczko, L: AUTHOR

Abstract

This control circuitry is arranged for multiple tests of electric circuits and components. A digital to analog (D/A) converter, e.g., type 803, circuit module 10 is connected in a head-disk assembly testing circuit, Manual switches 12, a diode 14, a light-emitting diode indicator 16 and a manual-automatic switch 21-22 (ganged, as indicated) are added, as shown. Trim resistors 24, 26 and 28 are chosen for optimum operation in the designated surface-analysis test system.

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Integrated D/A Converter Automatic/ Manual Control Circuitry

This control circuitry is arranged for multiple tests of electric circuits and components. A digital to analog (D/A) converter, e.g., type 803, circuit module 10 is connected in a head-disk assembly testing circuit, Manual switches 12, a diode 14, a light-emitting diode indicator 16 and a manual-automatic switch 21-22 (ganged, as indicated) are added, as shown. Trim resistors 24, 26 and 28 are chosen for optimum operation in the designated surface-analysis test system.

In the automatic mode, the logical data is entered into a tri-state latch 30 (a part of the D/A converter) under program control. Resistors 31-38 effectively isolate the latch output lines from the manual switch 12 lines, so that it matters not whether the individual switches 12 are open or closed.

In the manual mode, the tri-state latch 30 is switched into a high impedance state. Resistors 41-48 prevent the output lines from floating high. The logical data is now entered by manipulating the manual switches individually. The latter mode enables easy adjustment of the component/circuitry under test.

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