This circuit, with a 12 V input, was found in a Popular Electronics from the 1990s. Information is given about the ferrite-wrapped transformer. The transistor must be mounted on a heatsink.
This source is used to supply circuits with operational amplifiers, being originally created for...
The transistors in this 80's documentation project may be BC548, the most modern equivalents of...
This circuit uses a FET to drive an LED with constante currente. The current up to 20 mA can be...