This circuit applies to an old dial phone by detecting light pulses in the dial. The circuit is from an old 80's Electronic Design.
The critical component of this amplifier is the output transformer. We found the circuit in an old...
This circuit was found in the January 1989 issue of Radio Electronics magazine. The circuit sends...
This circuit was found in a 1980s documentation. Q1 and Q2 can be BC548 and SCR a TIC106. The...