On Thu, Feb 7, 2013 at 9:09 AM, Zitt <zittw...@gmail.com> wrote: >> You could maybe regulate the nixie current (instead of using LEDs) so >> the active display is brighter than the inactive one. > > Hadn't considered. Truth be told; I saw the LED back lit clocks and > basically thought it was a cool idea. > Maybe I'll do that on Rev2.
It would be worth a try to try it out, but I suspect that the back-lighting will look nicer. > > On Thursday, February 7, 2013 4:25:09 AM UTC-6, mikegregg wrote: > > <<The first this I see that I do not understand is here I see the opto > isolator. As I understand it, you are planning on running the leds > through it. > > The construction of your circuit is a bit confusing to me. It looks > like you are running the base rail of the transistors for your led's > off of a line going through the first led(Q7A)? I'm not sure why you > are doing that. Are you trying to use the led as a current regulator > or something? >> > > Q7A is a diode connected Transistor; which is the left half of a standard > Current Mirror. > The LED (D7A) and the .7V diode connected transistor are driven by R62 as a > current limitor. > Q22 provides a propotional voltage drop against the setting of the Pot at > R65. The idea here is that R65 controls the brightness of that single LED > (D7A); which is "current mirrored" into the other LEDs. So; controlling one > LEDs brightness is "mirrored" into the others. > Q7B-Q1B are all the other side of a current mirror. > http://www.allaboutcircuits.com/vol_3/chpt_4/14.html I see. Thank you for the explination. > > <<It's a good idea to put a limiting resistor on the anodes of your > Nixie tubes to avoid burning them out if you accidentally turn > multiple legs on.>> > > Already present. 12.5K ... ie R13. > > > <<I do not know what your incoming data is like, so I cannot speak very > much to the rest of your circuit. It looks like you get the display > data in on a 4 bit BCD shift register? >> > > Correct; BCD for the digit. And D7-D1 controlls which "anode" is updated. > > > <<What is the section of the circuit with the 4555d and 4503d components > doing? >> > > Address translation for 7digit displays in a 6digit system. Item#2 above: > http://www.pinball4you.ch/okaegi/pro_d7.html Ohh, that makes sense. That explains all of > > <<I hope you'll post images of your finished product when you are done. :) >>> > > Certainly. :D > > John > > -- > You received this message because you are subscribed to the Google Groups > "neonixie-l" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to neonixie-l+unsubscr...@googlegroups.com. > To post to this group, send an email to neonixie-l@googlegroups.com. > To view this discussion on the web, visit > https://groups.google.com/d/msg/neonixie-l/-/9jNsnhOb8eMJ. > > For more options, visit https://groups.google.com/groups/opt_out. > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
