This 12 V x 2 A regulator was found in 1965 Delco Radio documentation. The circuit uses transistors from that time. The input voltage can vary by 15% around the indicated value.
We found this circuit in a Popular Electronics of the 90s. The circuit still uses light bulbs, but...
This circuit is from Linear Technology 2005 documentation. The circuit is based on company...
The integrated circuit used in this power supply is no longer very common in power supplies today....