This simple source uses two 2N3055 transistors that must be equipped with good heat sinks. The source has no protection, only an input fuse. The diodes are for 5 A x 50 V or more.
By connecting several photocells in series, we can directly activate a sensitive relay, as shown in...
The purpose of this circuit is to provide a constant current to an experimental electromagnet. The...
Found in Linear Technology documentation from the 90s, this circuit uses components from that...