We found this circuit in a 1985 documentation. The transformer is an old TV flyback that has an exposed part of the core, where 10 to 20 turns of common wire are wrapped.
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...