Hello,
I'm building clock with four IN-4 and INS-1 Neon Tube colons. I have everything wired but i'm having some issues with the MOSFET heating up and an issue where voltage is leaking to cathodes. For example, anode2 is shared by a nixie tube (cathode1) and the INS-1 colon (cathode1). When i fire the colon, some voltage is bleeding through to the nixie tube.
I'm wondering if i damaged the SN74141's. I didnt' have any sockets on hand and impatiently solder'd them directly.
FYI, here's a link to my Driver software. Still a work in progress. If the C++ pattern ends up being too slow i'll re-write it in C-style code:
https://github.com/waldo1979/WitchingHour
-Waldo
I'm building clock with four IN-4 and INS-1 Neon Tube colons. I have everything wired but i'm having some issues with the MOSFET heating up and an issue where voltage is leaking to cathodes. For example, anode2 is shared by a nixie tube (cathode1) and the INS-1 colon (cathode1). When i fire the colon, some voltage is bleeding through to the nixie tube.
I'm wondering if i damaged the SN74141's. I didnt' have any sockets on hand and impatiently solder'd them directly.
FYI, here's a link to my Driver software. Still a work in progress. If the C++ pattern ends up being too slow i'll re-write it in C-style code:
https://github.com/waldo1979/WitchingHour
-Waldo
Can you tell me a bit about your setup?
Do the tube and colon share a common anode as well?
Are they both resistored on the anode?
Try different anode channel per unit. And use the multiplexing to gate them.
Below is a table describing my tube wiring. The nixies have a 10k resistor on the anodes and the neons are connected in series with a 47k resistor. When I illuminate the neon tubes (colon) and leave it on the Nixie->hour2 has a ghost. Using a different anodes have the same effect. if i illuminate in a loop with a delay the ghosting isnt visible.
The wiring to the tubes is AWG 28 (http://amzn.com/B007R9SQQM), which might be a little small. The tubes are socketed using sockets from Germany i bought off ebay: http://www.ebay.com/itm/331114980365
When the neon tube is illuminated, if i take a voltage reading from the cathode pins which are supposed to be in the off/low state and ground there is 140~ volts. I checked for shorts but didn't see any. Seems like the problem lies within the shift registers.
Anode1 | Nixie->Hour1 |
Anode2 | Nixie->Hour2, Neon Tubes |
Anode3 | Nixie->minute1 |
Anode4 | Nixie->minute2 |
Cathode0 | Nixie->hour1, Nixie->hour2 |
Cathode1 | Nixie->Minute1, Nixie->Minute2, Neon Tubes |