The CA3020 integrated circuit was one of the first commercial types, sold in the 1960s. The circuit presented is from 1968 using a power stage with RCA transistors of the time.
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...