This humidity sensor indicates the different levels of conduction of the sensors through an LED bar. The circuit is from Popular Electronics and must be powered by cells or battery.
Critical components of this project are the Geiger tube and the 300V battery. The battery can be...
In the figure we have a circuit that fires from a positive pulse of short duration applied to its...
This circuit was obtained in a French documentation from 1981 and can be easily assembled. The...