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Topic: Multiplexing nixie tubes (Read 1 time) previous topic - next topic

stoopkid

This is more of a nixie question than arduino, I'm sorry, I just don't really know a batter place to ask...

I read that multiplexing nixies increases their life(does any know if that's true?). Also it would be nice to have less wiring and only need to power two at a time. Does anyone know if the 74141's used to drive nixies can be used on their anodes too? Or if not, can I use an npn transistor rated for 200v with the ardiuno?

Thanks

CrossRoads

If you are driving the anode, you will probably need to use PNP, or P-channel MOSFET - but will have to make up a 'driver' for it, like an NPN open collector that is pulled high for turn on and the NPN pulling low to turn it off.
Hard to give better advice without seeing your schematic.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Federico

I am working with nixies right now and I am multiplexing them.
I use the 74141 as cathode driver and a circuit made with trasistors to drive the anodes.
I am using the last scheme in this pdf http://www.google.com/url?sa=D&q=http://nixietube.info/NixieTransistors.pdf with 10k resistors.

This is a pic of my test schematic (still working on it, but working as of now)


This is a pic of my actual mess
Federico - Sideralis
Arduino &C: http://www.sideralis.org
Foto: http://blackman.amicofigo.com

CrossRoads

So you have HC595 driving an NPN to drive the PNP.
In that scheme, the 595 High output will turn on the NPN and turn Off the PNP?
So if the 595 is not driving (or is powered off), the NPN will be off and All the PNPs will be on.
Is that acceptable behavior?
Or do you want another stage of inverter such that the PNP only goes on with valid high from the 595?
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

wyager

#4
Mar 08, 2011, 04:50 am Last Edit: Mar 08, 2011, 04:52 am by wyager Reason: 1

So you have HC595 driving an NPN to drive the PNP.
In that scheme, the 595 High output will turn on the NPN and turn Off the PNP?
So if the 595 is not driving (or is powered off), the NPN will be off and All the PNPs will be on.
Is that acceptable behavior?
Or do you want another stage of inverter such that the PNP only goes on with valid high from the 595?


I'm not sure what you mean, this schematic is active high. Pulling the NPN base high lets current flow from the collector, which pulls low the PNP's base and lets current flow from the emitter to the collector which powers the anode. So turning the NPN on turns on the PNP as well...
At least, I think that's how it works.

But I know for a fact that this circuit is active high, it's the same one I'm using.

CrossRoads

Ok, maybe I have how PNP works backwards, I don't use them for anything.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

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