Found in the April 1978 issue of Radio Electronics magazine, this circuit is intended to be powered by a symmetrical 15 V source. The signals are low intensity.
Found in a General Electric documentation from the 1980s, this circuit makes use of a FET...
This circuit is based on an MC1408, an integrated circuit that is not common today. The...
Another way to increase the sensitivity of the circuit with the amplification of the sensor...