This circuit triggers a buzzer or other warning device when the light falling on the sensor is cut off. We found it in the Encyclopedia of Electronic Circuits Volume 5 of 1995.
We found this relaxation oscillator in a 1967 General Electric documentation. The frequency is given...
This circuit generates a 20 MHz sinusoidal signal from a 10 MHz crystal. It is found in the 1992...
This circuit is from a 1967 publication. The potentiometer above 4M7 is the critical component. The...