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Summer Project - Nixie Clock

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Frozenoak

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Hello all,

I am on my summer break and am finding myself with a little extra time. I have recently fallen in love with the nixie tube and have decided that I want to build myself a Nixie Clock from the ground up. If that goes well I hope to build three and possibly a watch, but that all hinges on the project before.

A little background about me might help. I have little to no practical experience with electronic circuits. I took a Marine Corps Avionics course in 2000 which taught me what a circuit is and most if not all of the standard components. I can, with some difficulty, read a wiring diagram. In the Marine Corps I was a Calibration and Repair tech who worked mostly on Physical Dimensional tools but I was trained to (and had some minimal contact with) troubleshoot electronics to component level. All that being said...I want to design a functional circuit, Layout and Etch the PCB, gather all the necessary components and assemble a working clock.

The first step will be a 4 digit clock with as simple a circuit as possible. The second may be something more complicated, possibly with a programed chip or wwvb or gps element. The third, and real goal, will be a 12 to 14 digit clock showing time and date (haven't decided on 2 or 4 year format) with a decatron as a 10th of a second analogish meter, like this one I found at Nixie Clock gallery . The watch I may throw in if I'm feeling a little frisky after everything else.

I am hoping to use this forum as a sounding board. I hope I don't ask to many noob questions as I do try to do my research before I ask questions. However, there is a lot of bits and pieces to track so I need somewhere other than my head to store all the different threads, and hopefully get some feedback along the way.

Please feel free to let me know what you think.

Regards,
dale
 
Hi Dale and welcome to the forums!

Far be it from me to dissuade what you want to do, however, you may want to start off with some basic clock circuits using just plain, simple and reasonably priced seven segment LED displays.

Now if you really want to take the nixie tube route that is fine but be aware that the tubes are expensive. They haven't been manufactured in the US for decades and I believe most if not all made today or of Russian manufacture. With the nixie enjoying a sort of comeback there is no shortage of tutorials like this and kits available. You may want to consider starting with a kit.

Marine Corps calibration huh? Years ago for a Marine Corps cal lab at the AIMD level (Level 4) electrical electronic was phases A&C and physical dimensional was phases B&D. I worked extensively with the Navy / Marine Corps METCAL (Metrology Calibration) programs during the mid 70s. Back then, there was no shortage of nixie tubes in everything. :)

When you have questions just ask. I think you will find this forum very friendly and helpful.

Semper Fi
Ron
 
Thanks Ron,

It would appear that nothing has changed in the Marine Corps since the 70's. I was AIMD level wich is still called level 4 and I was phase B&D. There are not many people that would know that. I guess I'm in the right place.

The impetus for this project is an old DC volt meter that the company I work for recieved in a shippment of spare/scrap machines they bought for one item that was in the lot. I was able to buy the meter from them for $5. It has 6 nixies in it which appear to be fully functioning but I have not tested them yet. I will also be able to salvage the drivers and a whole host of other electronics if need be. I have been looking on-line at the prices of nixies and you are right they are pricey but I hope to sell one of the first clocks to pay for the final clock.

Most of my questions will be in the "what size" catagory, meaning what size resistors or capacitors and such. I have forgoten just about all the math they taught me in 2000 regarding circuts. I am trying to create a more or less working schematic (less the values) and want to have it ready by this weekend.

Regards,
dale

P.S. I have looked into the Kits and while they are tempting they would not really challange me. I want this to be a learning experiance with a tangible conclusion.
 
Have you looked at some Nixie circuits? A Google of "Nixie drivers" came up with numerous hits including one like this.
 
Hi crustchow,

I have been looking at nixie clock circuits. I am modeling mine on Mike Harrison's. I am attaching what I have so far. I am pretty much following his design but I want to understand what each part is doing instead of just throwing it in there.

It is a little more tricky than I had first assumed. Especially the hours. I have settled on using 4017's for the minuets and one's of hours and a 4013 for the ten's of hours. Reseting the one's of hours still eludes me but I am fairly certain I will figure that part out pretty quick.

The part that I am avoiding for right now is the input signal. I am still weighing my options. I have been reading for about an hour about using crystals and dividing the signal down which in my mind would have a cleaner signal (square wave). The other option seems pretty straight forward, use the 60hz the city supplies me and divide it down with a couple more 4017's (which would make adding seconds almost automatic). My major concern with this option is how clean and accurate the signal is. I assume but don't really know that the 60hz signal that comes out of the wall is sinusoidal and would need to first be squared off... I guess that doesn't sound all that bad. I will have to read up on it tomorrow.

Regards,
dale
 

Attachments

  • nixie_clock_v01_inc.png
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Alright, I downloaded Eagle and played around with it this week. I have what I believe is a complete schematic but almost none of the components are correct (I couldn't find the correct components in the Libraries). Can I post what I have here and get some advice from everyone?
 
Alright, I downloaded Eagle and played around with it this week. I have what I believe is a complete schematic but almost none of the components are correct (I couldn't find the correct components in the Libraries). Can I post what I have here and get some advice from everyone?
Please do. And tell us what components you can't find.... library organization is a problem for many of us using Eagle.
 
Will do.

I have used a number of place holders here in order to be able to draw the darn thing out. I will now have to go back and replace them with the actual devices assuming they can be found. Here is a list of items I couldn't find.

OK1 should be NEC2502-1
Q1 through Q28 should be MPSA42
N1 and N2 should be B-5440 (Nixie tubes with 2 anodes)
N3 and N4 should be B-5441 (Nixie tubes with 2 anodes and 2 decimal points)
S1 should be a momentary toggle or rocker switch attached to the back of the clock to set min and hrs. any suggestions concerning alternatives would be more than welcome.

I don't know what part numbers (taking into account tolerances, volts and all those considerations) to use for any of the capacitors, resistors, diodes and the zener diode (D4). As a matter of fact I don't even know what values I should be using for the diodes. I know their function and I kind of know how they work but I have no idea how to give them values. Also, the capacitors my be in the wrong orientation, I wasn't aware until yesterday that cap's had pos and neg sides (I guess I should have though).

The Power supply scares me so if someone would give that some special attention I would appreciate it. Especially where I am trying to supply +5v to OK1 and how to get the 0v's tied back into the circuit.

For the 60hz clock I used Dave Johnson's drawing from over at Discovercircuits.com and the rest I got from Mike Harrison over at Mike's Electric Stuff I tried to use only the parts that applied to a 115vac 60hz supply.

Thanks in advance and if this is to involved for a forum let me know what I can do on my end to make it less complicated.

Regards,
dale
 

Attachments

  • nixie_clock_v1.png
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apparently my last post is in moderation. How long does it usually take for a post to clear that process?

This is it.

OK1 should be NEC2502-1
S1 should be a momentary rocker or toggle switch that will get attached to the back of the clock housing
Q1 through Q28 should be MPSA42
N1 and N2 are B-5440 (Burroughs nixie tubes with 2 anodes)
N3 and N4 are B-5441 (Burroughs nixie tubes with 2 anodes and 3 decimal points)

All the values I have for resistors, capacitors, and diodes were swiped from the drawings I am referencing but I don't know if any of them are correct and a number of them aren't given so I don't have a lot of the values. Also, I relearned today that capacitors have a + and - side. I had forgotten that so some of my capacitors may be oriented incorrectly.

I used Mike Harrison's schematic for the large majority of mine and Dave Johnson's schematic for the 60hz signal.

I can say with some confidence now that I know the difference between designing and engineering.
 

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  • nixie_clock_v1.png
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I think it is only your first three posts that get moderated if they have an attachment. Try posting the file again.

Mike.
 
Thanks Pommie,

I was editing my post do to just that while you were posting.

I have one additional question. How do I tell Eagle that I am plugging this thing into the wall? I keep getting the error NO SUPPLY.

Regards,
dale
 
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It means that one of the chips has a pin designated as class 'power' (ground is also in this class) which is not connected (Eagle knows it has to be connected to something.). Usually it's sufficient to attach a net to the pin and give the net a name. Some chips have a separate symbol for the power/ground pins. If some of the chip isn't anywhere on the schematic, use the 'invoke' command to make that section appear.
 
Do the 4017 and 4013 chips need power? It makes sense to me but I was talking to one of the guys at work and he said they probably don't. I don't mind invoking one but what then? Do I supply 5v to that pin? Am I doing anything right?
 
The chips aren't connected to the mains, but they don't work on air. They have a power and gnd connection.

Look in the Help section for the 'invoke' command.
 
OK, I invoked PWRN which gave me 2 pins, VDD and VSS. I connected +5v to VDD and 0v to VSS. That eliminated all my errors, now I have a bunch of warnings on those same pins.
 
I can live with that. Can someone look over my schematic and help me solve the numerous problems with it? Specifically the values for the resistors, capacitors and diodes.
 
Ok, I think I have most of this figgured out. I am still not sure about the circuitry surounding the 10hrs nixie ( that's a jumbled mess I need to spend time on. And I don't know the math to find the appropriate Resistances for r1-r4, r33&r34. The schematic I am using says there should be 230v on that top line. I only need 170v to rum my tubes. What is a function that I can use to find these resistance values?

Regards,
dale
 
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