OSCILLATOR_ADJUSTABLE_OVER_10_1_RANGE

Published:2009/7/5 22:48:00 Author:May | From:SeekIC

In this circuit, there are two feedback paths around an op amp. One is positive dc feedback which forms a Schmitt trigger. The other is a CR timing network. Imagine that the output voltage is +10V. The voltage at the noninverting terminal is +15V. The voltage at the inverting terminal is a rising voltage with a time constant of CTRT. When this voltage exceeds + 5V, the op amp's output will go low and the Schmitt trigger action will make it snap into its negative state. Now the output is - 10 V and the voltage at the inverting terminal falls with the time constant as before. By changing this time constant with a variable resistor, a variable frequency oscillation may be produced.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Signal_Processing/Oscillator_Circuit/OSCILLATOR_ADJUSTABLE_OVER_10_1_RANGE.html

Print this Page | Comments | Reading(3)