We found this circuit in an 80s Intersil documentation. Modern equivalent operating systems can be used. The potentiometer adjusts the detection level.
This VCO makes use of components from the 1980s. The circuit can be implemented with modern...
This circuit uses an LDR as a sensor to trigger an LED indicator at a preset lighting level. The...
This circuit was found in a 1968 General Electric documentation. It has an input impedance of 2 M ohms...