The circuit uses operations that are no longer common nowadays, as it is a configuration obtained in the Linear Applications Handbook of the National Semiconductor of 1994.
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...