With an 18 V input, this regulator was found in Philips documentation from the 60's. The transistors are from that time. The power transistor must have a heatsink.
This power supply also has a fine adjustment feature. The transformer is 16 + 16 V with 3 A and...
This circuit was obtained in a 1985s English magazine. The circuit can still be assembled with...
The circuit shown in the figure is suggested by Texas Instruments in its Linear Circuits...