Found in a 90’s Electronics Now, this circuit has its output connected to an audio amplifier. The transducer is the type that fits on the finger to monitor the transparency and thus the beats.
This circuit trips when a negative pulse is applied to its input or when the voltage drops below a...
This is an old 1988 circuit consisting of a timer or time control for exposing silk-screen arrays. The...
This circuit was taken from an old American documentation. It can be built with modern op amps. The...