This is the top and bottom of the 4017's, i actually have no reason to think this board was malfunctioning, it was counting correctly... till it died, and overheated and gave me a blister
like i said earlier the only thing i saw funny happening with this was the 3 numeral was lighting up on both nixies for some reason

 

See this thread: http://forum.allaboutcircuits.com/showthread.php?t=45583

Add a regulator to your circuit. You might as well replace all of your IC's; as I think they got toasted.

 

And lastly, top and bottom of the nixie "driver?" circuit, not sure what to call it, it also worked last year, all of this did. The only thing i changed this time was adding the resistor, which i did because it was recommended in the earlier post to reduce the voltage to the nixies.
The more i think about it the more it makes sense that they might have been ruined by current getting through the transistors.
"coming out of saturation" as sgt. wookie put it
Also, a pic of how everything wires together, without the resistor.

 

i plan on replacing all the ic's, possibly the crystal, and im guessing im probably going to need new transistors?
by regulator im assuming you mean for the vdd?

 

Yes, regulator for Vdd.

You could check the transistors before you replaced them. However, replace the IC's first, and add bypass caps to each IC. Looks like you've plugged the Nixie tubes into sockets; so you could carefully pull them out and test the transistors using a current limiting resistor around 3.3k to Vdd to see if the voltage at each collector varied between Vdd and nearly 0v when the transistor switched.

 

The bypass caps are the ones that go directly from the vdd in on the ic to ground, correct?
And the ones in a signal line are the decoupling?

 

I'd guess that all your logic ICs got smoked.

As for the board, soldering skills need a little brushing up, might want to grab some desoldering wick or a solder sucker so big blobs aren't in some places, and add a tiny amount of solder in the areas where wires aren't fully covered.

Best tip for you would be getting a much smaller diameter solder, the smallest available. I use 0.018", or 0.032" if working on "bigger stuff".

 

.032 is currently the smallest i have, courtesy of radioshack, what i wouldn't give for a store that actually sells this stuff
Im also getting a shipment of some copper-clad and some etchant and such, hopefully making pcbs for some of this will help clear up sloppy wiring issues

 

Okeydokey, Think i have the bypass concept down, is there anywhere i should put decoupling capacitors?

 

Bypass capacitors is another name for decoupling capacitors; same thing.

The idea is to have a small 0.1uF/100nF capacitor across the Vdd and GND pins of each IC. It's really important, or we wouldn't suggest it.

Your long wires are likely causing problems. If you could get the whole thing on a smaller custom PCB, you'd be a lot better off.

 

Ok, so is there anywhere i should put a cap in the signal line?
Also, what software would you recommend for generating pcb layouts (free), and is there anything i should know about making them involving voltages this high/signal stuff/making them in general?

 

Ok, so is there anywhere i should put a cap in the signal line?

No. You might need to put resistors in long wires to keep them from "ringing" due to the inductance of the wiring. A piece of paper clip wire roughly 10mm long has roughly 15nH inductance. Inductance adds up fast. The inputs to CMOS gates look like small capacitors, so what you wind up with electrically is a series LC circuit that will oscillate at high frequencies when you suddenly change the signal level to it.

Also, what software would you recommend for generating pcb layouts (free), and is there anything i should know about making them involving voltages this high/signal stuff/making them in general?

I've been using Cadsoft's Eagle, but the freeware version is limited to a board that's roughly 4" x 3".

ExpressPCB/ExpressSCH doesn't have a board size limit, but I haven't used it much.

Some folks like PCBtrace, but I haven't tried it.

Leave a good bit of room around the HV traces. Try to avoid sharp corners with the HV traces and pads.

 

out of pure curiosity, why should sharp corners be avoided?

 

Because almost all photographic techniques tend to pinch sharp corners. Look at a Xerox copy sometimes, under a magnifying glass.

Whether you use toner transfer techniques or true photographic techniqes these pinch points can be a problem. Curves and 45° angles solve the problem.

 

Well actually, sharp corners are not so critical on a high positive voltage. It's the negative voltage where electrons tend to get emitted from sharp edges.

On the "ringing", see the attached - what happens when you have a foot long piece of wire with a capacitor at the far end, and you switch the signal level quickly.

Note the damping effect that the resistor has on the circuit on the right.

 

alright, im probably going to sound n00b but, why / how does the resistor dampen the inductance effect and why doesn't it reduce the voltage any?

 

Think of ringing as a wave bouncing back and forth. Every time the wave goes through the resistor it is attenuated a lot, so quickly stops. Without the resistor to absorb the energy it would last a lot longer.

 

Alright thanks, that makes sense
Is stranded or solid core wire better?
i remember something about skin effect being reduced in stranded...

 

You're better off to put most of the wiring into traces on a circuit board. Flat, wide traces have less inductance than wire.

Use stranded for off-board connections, as it's more durable when flexed.

If you need to use on-board jumpers for a PCB, then use solid wire.

 

Alright, i still have one major issue tho, how should i reduce the current to the nixies?
My converter says 180V @ 12mA out, nixies need 170 to light, they will run at that or even down to 150ish once lit without problems, and they need 2.5mA.
how can i do this?