Classic Neon Lamp Can Resolve Your AC Power Indicator Mandate

 

The really interesting thing about the neon indicator is that if you have a variable resistor in series, it is possible to have a value that will have the lite illuminate when light hits it and go dark when the light is removed. The inverse nightlight function. I just explained the mechanism of that in another thread.

 

The NE2 was my first favorite light to play with. Back - way back - way WAY back in high school electronics class I built a number of relaxation oscillators. Simple 110VAC, diode, resistor, cap and neon lamp. It took years to understand what was happening but this was the experience:

Having an RO running, the NE2 flashing at a rate (making up numbers here) 2 flashes per second. When I put my finger near the lamp the flash rate would increase to 3 or 4 flashes per second.

This is my theory as to why this was going on: The NE2 requires approximately 70 volts to ignite. As the voltage in the cap rose it would after the RC constant ignite the neon. This would conduct the capacitor charge down to a point where the lamp extinguished. When placing my finger near the lamp the flash rate would increase due to the presence of a static field (my finger). This would result in a pre-charge developing on the electrodes meaning the 70V ignition point was reaches sooner, causing the flash rate to accelerate.

Warning: If you wish to try this experiment be mindful of the high voltage. TOUCHING the glass bulb might be safe. But the close proximity to the high voltage could cause a personal shock. Take steps to avoid contacting live wires. Or live dangerously and ignore that advice.