Dummies guide to building a 120watt 140 volt power supply to drive IN-9 Nixie tubes.

[spec]

Fancy having Old Rosie in Oz- you are obviously a man of some taste.

spec

 

[fireant007]

When the circuit is wired with your schematic .. it does not work.
When I swap the anode resistor to the supply side it works !

As for having a transistor that's why I put the 220 ohm resistor there .. to limit the current to 12mA. ... If you look on the original data sheets you don't see any transistor ?
There is not one nixie or in-9 circut I have ever seen that puts the anode resistor on the cathode side.

I can drive my display up and down very nicely with the little resistor substitution wheel I have.
So .. I am pretty sure that this is the correct way to wire it up.

If you swap a tube around the other way in the SAME circuit .. it does NOT light .. unless you turn up the voltage to 300Vdc.
I have done it ... I have seen it.

 

[fireant007]

Fancy having Old Rosie in Oz- you are obviously a man of some taste.

spec

Not for old Rosie I don't ! ....
Do they put washing powder in it ?

 

[fireant007]

Tell you what .. pm me your address ....
I will post a few tubes to you for your help and experimentation !

 

[spec]

Multiplexing the tubes would be bad. That is not what I am suggesting. Instead I think that you should probably multiplex the input to the opamps driving the current transistors.

You could have a small capacitor on the input of each opamp and systematically refresh the voltage on that capacitor to define the ionizing current through the tube.

The tubes would not be aware of the multiplexing and would just see a fixed ionizing current at any one time.

spec

 

[spec]

Tell you what .. pm me your address ....
I will post a few tubes to you for your help and experimentation !

Thanks, but afraid I do not have a workshop at the moment to do any experiments.
spec

 

[fireant007]

Oh.. god yes .. not the supply voltage.
Would probably interfere with the local radio station !
No ... as I said .. in software via arduino via the op amp....

I need to go op amp .. because anode voltage does effect these things .. 150 to 155 moves the bar.
So I will be relying on the opamp to provide feedback for current stability.

 

[spec]

Not for old Rosie I don't ! ....
Do they put washing powder in it ?

You don't appreciate the subtitle aromas of apple blossom and oak, or the delicate hint of fresh virgin's pee until the fourth pint.

 

[fireant007]

You don't appreciate the subtitle aromas of apple blossom and oak, or the delicate hint of fresh virgins pee until the fourth pint.

Chortle chortle.... I have noticed that when I piss on my pants any stains on them come right out !

 

[Les Jones]

Hi fire,
You've got your decimal point in the wrong place. It should be 1.188 watts. I agree with spec that you MUST have the transistor in circuit. Also it cannot make any difference if the 4k7 is in series with the anode or cathode.

Les.

 

[spec]

I was in a Jazz pub in Bristol one night. The pub was packed to the gills and the band was so loud you didn't order a pint, you just pointed at a particular tap. All I could see between the bodies was this pump with Old Rosie on it, so I just pointed at that. My mates said that we had a great night- but I can't remember a thing about it.

 

[fireant007]

Hi fire,
You've got your decimal point in the wrong place. It should be 1.188 watts. I agree with spec that you MUST have the transistor in circuit. Also it cannot make any difference if the 4k7 is in series with the anode or cathode.

Les.

Roger roger.
Transistors are on order .. so I will test and report back.
Thanks for pointing out the math's error Les !

 

[fireant007]

I was in a Jazz pub in Bristol one night. The pub was packed to the gills and the band was so loud you didn't order a pint, you just pointed at a particular tap. All I could see between the bodies was this pump with Old Rosie on it, so I just pointed at that. My mates said that we had a great night- but I can't remember a thing about it.

Did you have nice stain free clothing ?

I might try it out for washing circuit boards ...

 

[fireant007]

Hi fire,
You've got your decimal point in the wrong place. It should be 1.188 watts. I agree with spec that you MUST have the transistor in circuit. Also it cannot make any difference if the 4k7 is in series with the anode or cathode.

Les.

Been thinking about this.
Why do I need a transistor ? .... when my resistor is controlling the current just nicely. ?
And .. as for the anode resistor ... I would agree if it were not an IN-9 .. my experiment proved it.

Still .. we will find out when I get my transistors.

 

[spec]

fire,

Can you wire up the test circuit below? Please ensure that the anode and cathode of the tube are connected as shown. Are the anode and cathode on the tube clearly identified?

spec

 

[fireant007]

Yup... sure can spec.
First thing tomorrow.

The thing is with these tubes is they are bar graphs .. not neons ... so that's why I doubt it will work.
Will make a video if I can.

Night mate.

 

[spec]

Did you have nice stain free clothing ?

I might try it out for washing circuit boards ...

No ptrobs at all- apparently I had around seven pints that night, so I was told.

Old Rosie is good for getting the glundge from the the bottom of your car (auto) engine (motor).

Don't put it anywhwere near circuit boards- ruins the flavor.

 

[spec]

Yup... sure can spec.
First thing tomorrow.

The thing is with these tubes is they are bar graphs .. not neons ... so that's why I doubt it will work.
Will make a video if I can.

Night mate.

Hmm, I might be missing something or reading the data sheets incorrectly.

If the test circuit does not work, there is something fundamentally wrong somewhere. This would need to be resolved before a display system could be developed.

spec

 

[dr pepper]

I've built a few 'nixie' clocks, one has an IV13 linear neon bargraph, they take more power than the average nixie.

There are 2 approaches, 1 is power them direct from the mains as vintage equipment often did, and the other is an smps, 100 tubes is going to use at least 100watts, so I'd be looking at a push pull converter, probably a sg3525 smps ic, and a etd39 or etd44 ceramic transformer, a couple of mosfets and the required dicretes, push pull mode without feedback would be adequate and simple.
Do you have much experience with switching supplies?

 

[fireant007]

Hmm, I might be missing something or reading the data sheets incorrectly.

If the test circuit does not work, there is something fundamentally wrong somewhere. This would need to be resolved before a display system could be developed.

spec

I am off to build....
Read this article .... might give you some insight.
https://www.dos4ever.com/Z550M/Z550M.html
Look at figure 12.... this is a similar concept to the IN-13 - the cousin of the IN-9