This circuit was found in 80's telecom documentation. Its purpose is to control a microphone in the process of transmitting voice and Morse signals.
This circuit fires at the touch of a sensor, passing its output from high to low in a time given by...
This circuit was found in a 1967 US publication. In it we have the implementation of a ring...
The strength of an audio signal can be controlled by touching sensors. Keeping the finger in...