Found in Popular Electronics from the 90s, this 1.5 A power supply can supply voltages selected by a switch. The splitter resistors determine the output steps.
This circuit was found in Fairchild documentation and does not require integrated circuits. It...
The circuit shown is from an old European publication. In it we have the way to activate a relay...
This is an old circuit, from 1997, when cathode ray kinescopes were still used in televisions. This...