> 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.
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 <<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 <<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.
