This circuit was suggested by General Electric / RCA in a 1980s documentation. The components are of the time and the circuit must be powered by symmetrical source.
This circuit is recommended for alarm systems since it has a good output stage. The circuit is...
) Suggested by Philips in a 1968 documentation this circuit has very high 10 ohm on-load voltage...
No information is given about the transformers in this circuit suggested by Motorola in a 1968...