This circuit, which is present in other points of this website, was found in a 90s Hands On Electronics. The circuit activates a buzzer with an oscillator.
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...