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 was obtained from a Radio Electronics in May 1967. The circuit consists of a system...
This simple two-transistor capacitance meter uses a 50 uA microammeter as an indicator instrument. The...
Found in a European magazine from the 90s, this circuit emits beeps that are several seconds apart to...