Nixie Tube Clock - Tried fixing current issues now all numbers light up.

Thread Starter

Charger15

Joined Sep 28, 2017
3
Hi everyone, I have been working on this for awhile now and thought I knew how to fix my problem but ended up creating another. I have made this nixie tube clock with the base from scratch and the board from GRA & AFCH. The initial problem that I ran into was since the wire I was using was 12 inches long there was not enough current to push up through to light the nixie tubes and only partial pieces of the numbers were lit. So my thought was that each tube has it's own resistors and after emailing GRA & AFCH and confirmed that replacing resistor 1-6 it would increase the current going to the tubes. So I took the trial and error approach and slowly worked my way down from the 23k (3k intervals) chip resistor that it came with to the 1k resistor that I am currently at. Probably trial and error was not the best approach. So currently I have hit the point where the number is fully lit but now it has all numbers within the tube lit. So now I am wondering what my next step should be or where I went wrong because I have hit a wall. Any suggestions or direction to go in would be greatly appreciated. Thanks.
20170819_084220.jpg 20170819_100322.jpg20170923_230054.jpg 20170923_230114.jpg
 

crutschow

Joined Mar 14, 2008
24,299
The initial problem that I ran into was since the wire I was using was 12 inches long there was not enough current to push up through to light the nixie tubes
The length of wire has absolutely nothing to do with your problem.

Can't really help unless you post your circuit which is driving the tubes.
 

crutschow

Joined Mar 14, 2008
24,299
Sorry forgot that. But the wire length would not add some resistance to the already small current output? Thanks.
Certainly it adds some very small resistance.
But the voltage drop across the wire is I*R so for small current and small resistance the voltage drop will be negligible.
 

bertus

Joined Apr 5, 2008
20,317
Hello,

What is the voltage on the HV connections?
What is the voltage on the HVMID_C pins of the HV5812WG chips?
The HV8512WG is designed for use with VFD tubes and not for nixie tubes, wich require higher voltages.
The IN14 datasheet states a supply voltage of 170 Volts and the HV5812WG chip states a max powersupply of 80 Volts.
It looks to me that the chips are blown.

Bertus
 

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Thread Starter

Charger15

Joined Sep 28, 2017
3
With the original resistor only one segment was lit on the shorter runs to the tubes and no lighting at all on the longer wire runs. Also when I plug the bulbs directly into the board with no wires the tubes work fine. I will have to measure what is coming out of the HV pin.
@crutschow
Thanks, I was really thinking about that incorrectly then.
 
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