Is direct-drive brighter? Definitely. Absolutely. Does direct-drive have longer nixie tube life? No. It's a simple function of duty cycle. If you have a clock with 1/6 duty cycle and running the tubes at the nominal current, then they should last 6x as long as they would have directly driven.
My thought for why multiplexing makes sense for running that many nixie tubes is simply the power consumption. Lets say you are planning to run 15 nixies at 2.5ma (180vdc): 37.5ma @180v. That's 6.75w! Let's further assume that you're getting 80% efficiency with your boost switching supplies, making the total power budget of just your nixies at 8.44w. With a 9-volt walwart, that's almost an amp of current right there, without factoring in anything else. -Adam On Wed, Feb 16, 2011 at 5:23 PM, Jarek <[email protected]> wrote: > One of the reasons I chose against multiplexing is simply that I have > the resources to drive them directly: the 74141 chips came with the > tubes, and my school gave my many 595s to play with. This way my > microcontroller can drive the milliseconds display directly, and > offload the seconds, minutes and hours to the 595 chips to drive the > 74141s, and I don't have to worry about cycle timing and assembly > instructions, not to mention having an (arguably) brighter display > with longer life and better current regulation. > > So based on the info here, I buy (http://cgi.ebay.com/Nixie-power- > supply-1363-/140426808956<http://cgi.ebay.com/Nixie-power-%0Asupply-1363-/140426808956>) > and get a resistor substitution box (I love > this thing) and stick my ammeter in between, then get resistors which > correspond to the highest value I can get without going above 2.5mA, > correct? I plan on powering the SMPS with a 12V wall-wart, so the > input shouldn't be a problem. > > Also, one last concern, my question about having the power supply off > board, how long can the wires be from the > board to the SMPS? > > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To post to this group, send an email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group at > http://groups.google.com/group/neonixie-l?hl=en-GB. > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
