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.
We found this transformer-isolated control circuit in a June 1995 Electronics Now. The triac must...
This circuit was found in a 1980s documentation. It triggers a relay when liquid from a reservoir...
This circuit shows on the screen of an oscilloscope two signals alternately at a frequency that depends...