Browse Prior Art Database

Light Sensitive Oscillator

IP.com Disclosure Number: IPCOM000075523D
Original Publication Date: 1971-Oct-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Huang, SS: AUTHOR

Abstract

The circuit produces an oscillatory signal at the collector terminal connection of transistors 3, 4 that varies in amplitude according to the intensity of light on a photosensitive device 5.

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Light Sensitive Oscillator

The circuit produces an oscillatory signal at the collector terminal connection of transistors 3, 4 that varies in amplitude according to the intensity of light on a photosensitive device 5.

A transistor 2 and associated resistors and capacitors are connected to form a conventional phase-shift oscillator. A signal at the collector terminal of transistor 2 is transmitted through the capacitor and resistor network to the base terminal of transistor 2 with a phase shift to maintain oscillation. Light-sensitive device 5 is connected to a point 7 in the phase-shift network to control the amplitude of the oscillation according to the resistance of device 5.

Device 5 also couples the oscillatory voltage at point 7 to the base terminal of transistor 3 which cooperates with transistor 4 to produce the amplified output voltage.

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