This circuit was originally intended for reading movie soundtracks. The circuit is from 1967 and was found in an English publication. The sensor is semiconductor type.
This circuit was found in the July 1969 Radio Electronics magazine. The circuit controls resistive...
August 2017 - Mouser Electronics is announcing the availability of TDK ICS-52000 microphones with...
The oscillator of this circuit operates around 8 MHz, but the output will be at a frequency three times...