on second thought, ill start a new thread for this

 

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?

Did you take a look at Ronald Dekker's page?

As far as measuring your Nixie current, right now you're using a 10k resistor between your 180v supply and your Nixie's anode/plate.
I=E/R.
I=?/10,000

Measure the voltage drop across the 10k resistor to determine the current through your Nixie tube element. Be careful, as it's high voltage.

With the cathode grounded (connected to the 180v supply return) you should measure E=IR = 2.5mA*10,000 = 25v if the current is 2.5mA.

2.5mA is the MAXIMUM for your Nixies.

I suggest that you keep the current under 2mA; which means that you should measure <20v across the resistor. If you measure >= 20v, then increase the size of the resistor.

 

Thanks!
im beginning to understand the applications of ohms law
(horrible i know, applying math just isnt my thing, concepts are)
I read through his "flyback converters for dummies" section,took notes on the equations
i hadn't had time to find his section on powering nixies yet, i will soon

 

You aren't alone; many of us (myself included) struggle with math.

I don't know a good way offhand to calculate exactly what value resistor that you will need if you find that you are getting >20v across your 10k resistor, as the conductivity of the ionized gas in the Nixie tube may change with the current through it.

I can only suggest that you might try using a pot in the range of 20k to 50k on the cathode (ground/return) side of the Nixie tube, and "tweak" it until you see around 18v-19v across the 10k resistor. Then power things down, and add the resistance of the pot to the 10k resistor, and that is your new resistor requirement. Don't leave a pot in the circuit permanently, as they are not anywhere near as reliable as fixed resistors.

 

Actually, when i was using it the nixies seemed very dim... I might need less
and would a rheostat be more reliable, assuming the resistor is still in the line?
i need something along those lines to control the brightness of the nixies, while they look dim in light they can be pretty bright in the dark

also, why have the pot on the cathode side and not the anode side?

 

Actually, when i was using it the nixies seemed very dim... I might need less

You won't know until you measure it, now will you?

and would a rheostat be more reliable, assuming the resistor is still in the line?

The term "rheostat" refers to a variable resistor with just two leads. A potentiometer aka "pot" has three leads, and can also be used as a rheostat by just using the wiper and one of the end connections. There are wire-wound rheostats, but they are expensive and generally pretty low in resistance.

i need something along those lines to control the brightness of the nixies, while they look dim in light they can be pretty bright in the dark.

I see. Well, might be possible to rig up a circuit with an LDR (light-dependent resistor) to change the current depending on the ambient light.

also, why have the pot on the cathode side and not the anode side?

That was just from the aspect of safety; if you were going to be adjusting it when the HV was on, it would be better to have the pot on the cathode side near ground.

 

right, just making sure there wasn't any electrical reason
Ill look into the LDR idea, but would there be a good way to actively control brightness, other than a simple on-off switch?