We found this circuit in a Radio Electronics from April 1965. The components are from the time and the power supply is for 12 V cars. The transistor must be equipped with a good heat radiator.
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...