We found this circuit in the October 1970 issue of Radio Electronics magazine. It uses the then-new CA3018 integrated circuit from RCA. Some resistors are required for best performance.
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...