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Control and Regulation System for Photocell Sensing Devices

IP.com Disclosure Number: IPCOM000094534D
Original Publication Date: 1965-Feb-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Prot, J: AUTHOR

Abstract

The regulation system compensates for the fluctuations of either the light source or sensing devices by controlling the light source.

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Control and Regulation System for Photocell Sensing Devices

The regulation system compensates for the fluctuations of either the light source or sensing devices by controlling the light source.

The intensity of the light on the sensing cells Ph', one only is shown, is measured by a complementary cell Ph. This is set in the neighborhood of the sensing cells Ph', in a similar position with regard to light source L and receives the light continuously. Cell Ph gives a voltage applied to a regulation device which controls the generator delivering the current to L. The intensity of the light is regulated in such a way that cells Ph', when lighted, deliver a determined voltage.

Phototransistor Ph has a variable resistor R in its collector. The voltage of the collector is applied to the base of a transistor T1, the output voltage of which is applied to T2. T2 constitutes a differential amplifier with T3, the base of which is maintained to a determined voltage. The output of T2 is applied through T4 to the current generator T5.

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