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Differential Level Detector with Dual Digital Outputs

IP.com Disclosure Number: IPCOM000092557D
Original Publication Date: 1966-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Fredriksen, TR: AUTHOR

Abstract

This device is useful in bang-bang control for sensing when two analog variables such as positional error and velocity are equal, one is larger than the other, or when either is larger in magnitude than a small fixed amount.

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Differential Level Detector with Dual Digital Outputs

This device is useful in bang-bang control for sensing when two analog variables such as positional error and velocity are equal, one is larger than the other, or when either is larger in magnitude than a small fixed amount.

The device is a level detector with dual digital as well as analog outputs which provide a limit function, null detection, and a hysteresis function. By adjustment of balance and gain control, a wide range of variations of these arrangements is possible.

As in drawing A, the device comprises a differential amplifier with two outputs, each connected to a Schmitt trigger. Drawings B and C illustrate the four output signals obtained with a balanced single input. One signal is a zero signal reference. Drawing D shows an absolute value limiter, null detector, obtained from the Ored output of outputs 1 and 2. Drawing E shows the symmetrical single output limiter using output 1 and offsetting the balance control to make e(1) = 0 coincide with E(0) 1/2. Drawing C shows the output of a flip-flop connected to outputs 3 and 4. This provides the hysteresis function of drawing F under a balanced condition. Drawing G shows a hysteresis output obtained from a Schmitt trigger output when the balance control is offset.

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