This circuit of starting lights for auto-race was found in an English documentation from the 80's. The LEDs must be of different colors, for greater realism.
Car battery charging can be done very simply with the indicated circuit. Although in the "fast"...
This battery-powered micropower supply was shown in Radio Electronics magazine in 1991. The...
In the figure we have the way to use the 555 to control loads in the bistable form. The circuit is...