Well, the tens of hours position is one issue. Alas and alack, the board is already made and even mounted in the case. I could do some add on action, but not much room. However, the Russian 74141 seems to be blanking that one OK. On future prpojects I will redesign the board. Great link, loved your site.
The real problem is blinking the nixies while the user is setting the time. I am blinking the pair of tubes being set, ie if setting the hours the two hours nixie blinks to show the user which tubes they are setting. And reccomends as to good ways to get a 74141 to blank properly? However, since I am using a RTC that is supposed to lose less than a minute a year and the clock is programmed to let you increment/decrement during operation the blink won't be used often. Especially as with the back up coin battery and super cap, it will keep the time for years even if turned off. So maybe I shouldn't worry about it too much. Thanks! Jonathan Its the 10 hours position ? Not the 10s minutes or 10s second ? Blanking those would just look weird. If so, that digit only light 0 & 1, in 12-hour mode, or 0, 1, & 2 in 24-hour mode. Why then use the 74141 at all ? If you do, then a quick fix would be to put a resistor (2 or 3, depending on 12/24 hr mode) across the anode, to the connected cathodes. Leave all other cathodes (3-9) disconnected. Calculate it so the drop across the anode-cathode is less than 120V. Say the anode resistor is 10K, the supply is 180V, and the zener break-over is 55V. 180V-120V-55V=5V. That means calculate the bleed cuurent so 5V is dropped across the anode resistor. If its 10K, the bleed is 5V/10K=0.5mA (500uA). This "bleed" is the "off" current. 120V/500uA=240K. So stick 220Ks across anode to each used cathode. That's ANODE, NOT Supply ! If its 12-hour mode try this scheme: http://threeneurons.files.wordpress.com/2011/08/hour_blk.gif Found on this page: http://threeneurons.wordpress.com/nixie-power-supply/ -- 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.
