Suggested by Amperex in 1968, this circuit is intended for hearing aids. The integrated circuit used, a TAA370 is not common today.
With two cascading tunnel diodes, this circuit found in a 196 General Electric documentation...
Found in General Electric's 1969 documentation, this circuit uses two Foto Darlingtons to control...
This circuit is used in the analog part of the telephone lines. The same circuit can directly...