This power supply circuit for high power audio amplifiers was found in Radio Electronics from the 90's. Power MOSFETs admit modern equivalents. The output current is 5 A.
An interesting timer is shown in the figure, using one of the 4 NAND gates of the integrated 4001....
General Electric suggests this circuit in a 1980s documentation. The operational of the time is...
This simple adjustable source uses a PNP transistor that can be the BD136 for even slightly higher...