I just received my two tubes today and powered them up. Severe cathode poisoning. Almost half doesn't glow. I wired it up in series with a 10k rheostat and milliampmeter to 120 VAC. I also placed a voltmeter across the tube. I ran the current from 20 mA up to 40 mA. At all current levels the voltage across the tube stayed at about 70 VAC. Looking at the box I saw that the tube was sold as a ballast regulator. From what I saw it seems to be regulating the voltage to 70 volts. I guess the next step would be to measure the volage across the rheostat, but if the voltage across the tube never changes then I expect the voltage across the resistance will stay the same as well.
Tried to find some web info on the theory of ballast regulators but nothing popped up that mentioned using a neon bulb. On Nov 8, 4:19 pm, threeneurons <threeneur...@yahoo.com> wrote: > So, back to the NE-70. If the voltage drop is small, say 25V, or less, > then there most likely is an internal limiting resistor. If it does > appear to have an internal resistor, then get rid of the external one. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to neonixi...@googlegroups.com. To unsubscribe from this group, send email to neonixie-l+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
