Hi Ron,
Providing the MPSA transistor is OK, it should work. There is one thought I have, since the bulbs require very little current to glow, could it be there is enough parasitic capacity in your wiring or circuit board to make them light? What if you were (for a test) to place a resistor of say 1 meg across the bulb and see what happens? It just may bleed off enough current to turn them off. I have also a selfish question. I see you are using a PIC and a DS1302 RTC. I happen to be working on a design (16 segment VFD) using the same parts. Do you program your PIC in assembly or something else? I use assembly, and if by chance you do also, I would be very grateful for a copy of the code section dealing with the DS1302. Thanks, Bill van Dijk From: [email protected] [mailto:[email protected]] On Behalf Of Ron Schuster Sent: Friday, September 07, 2012 10:39 AM To: [email protected] Subject: [neonixie-l] NE-2 lamps not fully blanking I've built a 4-digit IN-17 nixie clock based on a 1x4 mux design. It uses 4 neon lamps, 2 for the colon, 1 for the PM indicator and 1 for the Alarm On indicator. I have a small problem where I see a dim flicker in the lamps that are supposed to be off. They are driven as part of the nixie multiplexing circuit. One side of each lamp is tied to one of the digit anode drivers. The other sides are tied together and pulled to ground through one common MPSA42 "cathode" driver. I think I have sufficient blanking time between the digits. Each digit is on for 1 ms and the blanking time between digits is 100 uSec. The nixies are showing no ghosting at all. Any help in figuring out why my lamps are not turning fully off would be greatly appreciated. Schematics are attached. -- 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]. To view this discussion on the web, visit https://groups.google.com/d/msg/neonixie-l/-/RssVX0Tgn2kJ. For more options, visit https://groups.google.com/groups/opt_out. _____ No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2197 / Virus Database: 2437/5254 - Release Date: 09/07/12 -- 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 https://groups.google.com/groups/opt_out.
