This circuit visually indicates that a high voltage is present in an outlet or other point. The neon lamp is common, and the appearance of the assembly is suggested in the same figure.
We find this circuit in a radio amateur publication of 1977. Its purpose is to measure the...
This inverter amplifier is from a 1992 publication. NPN transistors can be BC548 and PNP BC558....
I found this circuit in a 1986 English magazine. It can still be easily assembled, exchanging Q1...