Found in a 1967 Ferranti documentation, this regulator makes use of an operational amplifier of the time. The output current is only 5 mA.
The TDA2613 is the mono version of the TDA1521A and has pinouts compatible with an integrated...
This circuit from an old 1978 publication uses germanium transistors but can be implemented with...
This project shows how to use an SCR in a starter circuit for a common fluorescent lamp. The SCR...