We found this circuit in a documentation from the 90's. The coil has its characteristics given next to the diagram. Power is provided by a 9 V battery and a range of a few tens of meters.
This power supply has a resolution of 10 pA in the current range from -100 to +100 nA. The circuit is...
This circuit uses two unijunction transistors and only one capacitor, generating signals at a...
The sensors of this liquid alarm are formed by two pieces of wire with the ends peeled off. The...