This 1988 circuit makes a back-and-forth of LEDs whose speed is controlled by P1. All components used are common and the circuit can be powered by voltages from 6 to 9 V.
In the figure we have an improved method of varying the voltage of a 7812 regulator. The circuit is...
This 5-range current measurement circuit was found in the September 1989 issue of Radio...
Found in an old English publication this circuit uses a dual gate MOSFET. Coils not specified....