This circuit was found in a 1967 Electronics World. Transistor Q1 can be a TIP321 and Q2 can be a BC558. The indicator lamp is optional.
The output voltages of this power source are selected by a switch according to the capacitors. The...
This circuit is from a 90s Popular Electronics. The circuit employs a ZN461E that is not a common...
This circuit was found in Siliconix documentation from the 1980s. Equivalent operational...