Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Video Logarithmic Amplifier

IP.com Disclosure Number: IPCOM000073863D
Original Publication Date: 1971-Feb-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 23K

Publishing Venue

IBM

Related People

O'Malley, FL: AUTHOR

Abstract

Circuit 10 is a simplified log amplifier particularly useful for processing video pulses.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Video Logarithmic Amplifier

Circuit 10 is a simplified log amplifier particularly useful for processing video pulses.

Input pulse EIN is fed to an emitter-follower transistor 11 which has an inductor L1 in its collector circuit. The incoming voltage pulse EIN is converted thereby to a current pulse. Since the current provided by inductors L1 or L2 cannot be instantaneously supplied, it initially passes through the diode CR1 which is appropriately poled for this purpose. Diode CR1 is a log diode; and consequently, the output voltage Eout represents the log of the input voltage EIN. Inductor L2 and resistor R3 provide the initial and constant DC bias for CR1.

1

Page 2 of 2

2

[This page contains 1 picture or other non-text object]