This circuit has the spark duration controlled by a 555 timer. The circuit was found in the 1990 special issue of Radio Electronics Experimenter magazine.
If the input voltage falls below 12 V the LED glows up. Other voltages can be monitored by...
This motor control using transistors was found in a recent English publication. The circuit is for...
In the figure we have an electronic toy organ that can both serve to amuse children as a basis for...