Browse Prior Art Database

Signal Generator for use in Spectrometer Amplifiers

IP.com Disclosure Number: IPCOM000097602D
Original Publication Date: 1961-Mar-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Kessler, HK: AUTHOR

Abstract

The measurement of low light intensities calls for high signal-to-noise ratio amplifiers. A correlation type amplifier is often used for this purpose. The light to be measured is chopped and the derived main signal is passed through an amplifier stage tuned to the chopping frequency.

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

Signal Generator for use in Spectrometer Amplifiers

The measurement of low light intensities calls for high signal-to-noise ratio amplifiers. A correlation type amplifier is often used for this purpose. The light to be measured is chopped and the derived main signal is passed through an amplifier stage tuned to the chopping frequency.

Another signal suitably phased with respect to the light beam to be measured is derived from the same chopper and serves as the reference or correlation signal. Conventionally, this reference signal is either derived from another beam of light or is derived from changes in capacity as the chopper blades move past a stator plate.

In this system, the correlation or reference signal is derived from an inductive pickup. As the blades of the iron chopper disc pass the inductive pickup, signals are induced in the stator coil. The output reference signal and the radiation signal are then both fed to a bridgetype correlation detector.

1

Page 2 of 2

2

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