Browse Prior Art Database

Difference Detector

IP.com Disclosure Number: IPCOM000097960D
Original Publication Date: 1961-Oct-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Charles, FJ: AUTHOR [+2]

Abstract

The circuit operates at high speed to provide a gated output signal. The latter is equal to the difference in amplitude between two input pulses which are separated in time. The amplitude of the first pulse is equal to, or less than, the amplitude of the second pulse.

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Difference Detector

The circuit operates at high speed to provide a gated output signal. The latter is equal to the difference in amplitude between two input pulses which are separated in time. The amplitude of the first pulse is equal to, or less than, the amplitude of the second pulse.

The first pulse is applied to the base of transistor Q1, and its amplitude is stored by capacitor C1. The stored voltage level is differentiated by the network R1C2 to provide an output signal at this time. Dependent on the application, it may be necessary to gate out this signal. When the second pulse is applied to the base of Q1, the stored charge, which is representative of the amplitude of the first pulse, is increased to reflect the amplitude of the second pulse. The differentiating circuit recognizes only the shift in stored charge level. Thus, the output signal is the difference between the amplitudes of the two input pulses. The vacuum tube T1 is used to provide a high impedance discharge path for C1 to prevent the stored charge from leaking off. T2 is used to isolate R1 from a load impedance.

The circuit has the features of not requiring calibration and of utilizing the same transmission path for both input pulses.

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