On Saturday, September 29, 2012 6:20:38 PM UTC-4, pwalnuts wrote: > > Hi! I've been using INS-1 nixie lamps for a while and they have always > ended up flickering after a while. I think i might be doing a couple of > things wrong. > > A) Polarity. They light up any which way you wire them. from the Datasheet > (link) <http://tubehobby.com/datasheets/ins1.pdf> i can't definitively > tell what is the anode and what is the cathode. I know the dot means > something, but what it does I don't know. (Picture of INS-1 > <http://f.cl.ly/items/2g0Z301L1c3f2y1R0n1e/Image%202012-09-29%20at%204.51.03%20PM.png>) > > I have tried wiring them either way and they still flicker... This is what > I think it should be > http://f.cl.ly/items/2u1p3x3V263X3e3M0s3o/Image%202012-09-29%20at%205.34.01%20PM.png, > > is this correct? > > B) Current. I have a 170 VDC power supply with a 221k Ohm current limiting > resistor. It has been been running at 0.55mA. > > > I'm now trying a higher current limiting resistor that brings the current > down to 0.45mA. Seems to be working, but I've had ones that worked before > and then they start flickering. Thanks for any help! > > There have been several topics in this group discussing the "wobble" problem with INS-1 neon lamps. I've run into this problem myself using the INS-1 lamps as colon indicators for clocks. One clock's colons are fine after six months, another has only one lamp working after 4 months. Like you, I assumed that the dot/arrow indicate the cathode (negative) terminal. Several other posts say that the dot/arrow indicate the anode (positive) terminal, like https://groups.google.com/forum/?utm_source=digest&utm_medium=email/#!searchin/neonixie-l/INS-1/neonixie-l/KZccbl9bFIg/zffZFEdK1PQJ or https://groups.google.com/forum/?utm_source=digest&utm_medium=email/#!searchin/neonixie-l/INS-1/neonixie-l/awtYADE5WKo/b42oQ_JhfYIJ
I recently received a bag of 100 of the INS-1 lamps so I decided to experiment. I rigged up a breadboard with a full-wave rectifier, 68uf of filtering and a bank of 220K current-limiting resistors. I connected the dot/arrow leg of the lamp to the negative supply, and the other leg through the current limiting resistor to the positive supply. After several hours I would check for flickering/wobble. If a lamp was flickering, I would reverse it's polarity so the dot/arrow leg was positive. If the lamp still flicker after that I would remove it, move the lamps below it up one position on the bread board, and place a fresh lamp in the last position (dot/arrow to negative). After performing this test I found twelve of the one hundred lamps did not flicker, and every one of them were connected with the dot/arrow to the positive supply. On some of the flickering lamps I tried a 180k resistor instead of 220k, connecting positive to the dot/arrow. The higher current through the lamp made no difference, the lamp still flickered. > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/b5ae5ec9-f793-4fd1-8597-833c5c4d70d0%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
