Found in Ferranti's 1968 documentation, this circuit uses a Darlington photo transistor to drive a 12V relay. The circuit can be implemented with modern equivalent components.
We found this power supply in the 1982 SGS Linear Integrated Circuits manual. The L296 is not...
This circuit is from an English book from the 1980s. Transistors can be general-purpose types of...
The basis of this circuit is the integrated TA7205, which is not very common today. We found the...