Based on the 4017 integrated circuit, this circuit of a European 303 Circuits from the 90s, generates a pulse train in a relay that mimics the dialing of a telephone.
This circuit is from an old manual, but can be easily assembled as the integrated one is still...
The simple transistor test shown in the figure can be powered by a 9V battery. The test is for...
This regulator can use BD'136 as the main transistor and as a reference next to a BC548 zener. The...