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.
This circuit with 10 MHz and 1.25 MHz TTL outputs was found in an American documentation from the...
We found this circuit for vocal effects in the September 1990 issue of Radio Electronics magazine. The...
This is a voltmeter with high input resistance. The transistor is germanium. We found it in an...