What would have been much simpler and a lot less expensive would be to put a resistor across each neon lamp. Perhaps 10K ohms, although in PLC work we use 5600 ohm resistors. It totally prevents undesired triggering .
This is a great story, with even greater educational value.
WKetel, I agree the robustness of using a high voltage system was lost by allowing it to also be a very high impedance system, as well. Ah, nothing like adding a ballast resistor from time-to-time.
If shielded wires solved the problem, then it was not a magnetic field coupling issue but an electric field issue. At power frequencies, "shielded" cables do absolutely nothing to combat magnetic field coupling. The extremely low operating current of the NE-2 means that a long wire could easily couple (capacitively) enough energy from nearby high-voltage wiring to make it glow.
NASA's Orion Flight Software Production Systems Manager Darrel G. Raines joins Planet Analog Editor Steve Taranovich and Embedded.com Editor Max Maxfield to talk about embedded flight software used in Orion Spacecraft, part of NASA's Mars mission. Live radio show and live chat. Get your questions ready.
Brought to you by