I'm sure there is a thread on here about this but the search function is just not yeilding results for me.

Earlier this week I asked how to get the signal from a LM3916 to run a IN-13 nixie tube. Thanks to those who replied but I found that the answer was 10 times simpler than anyone, including me would have thought. Instead of 10 transistors I just ran the 10 LED leads into a LM358 and coupled that with my MJE340 and presto. Instant Nixie VU METER.

So enough of that. Now my problem is smoothing out the 10 outputs of the LM3916. As the nixie tube is running it lights up in 10 (not so) equal segments. For each LED circuit, about 1 cm of the tube lights. How can I smooth this out so I get a near smooth sweep of the tube?

So I know I need to whip up a digital to analog converter but I need some help with how a DIY DAC is actually made.

Thanks Guys.
-Dean

 

Problem solved.
Switched the 3916 to a 3914, hooked all outputs together and grounded them with a 2200uf cap.

Nice and smooth

 

Hi Greendean -

I am working on the same design - not as far along as you <bit of a nube>. Would you mind posting a schematic? thx much.