Contract work / Sensors & electronics
Neon indicator
A compact current-regulated neon indicator tested on both 120-volt and 240-volt AC supplies.
Open the numbered review →Circuit, package, and voltage comparison
Photos 240–242
A client needed a compact neon indicator that would work on both 120-volt and 220–240-volt AC supplies. This was my first project using current-limiting diodes to regulate the lamp current. The prototype gave a similar apparent brightness at the two supply voltages I tested.
A closer view of the slim indicator assembly. Keeping the current-regulating circuit and neon lamp in a small package was an important part of this client’s requirements.
I tested the indicators side by side on 120-volt and 240-volt AC supplies. The lamps appeared similar in brightness, which was the behavior I wanted from the current-regulating circuit. This photograph records the comparison rather than a calibrated light-output measurement.
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