I have one basic question for everyone: Why is multiplexing so commonly desired?
For my own uses, I have found direct drive to be simple, reliable, and completely free of any flicker or any of the other things that can plague a multiplexed readout. Chuck > > >---- Original Message ---- >From: [email protected] >To: [email protected] >Subject: RE: [neonixie-l] Re: recommendation for anode resistor for >2x2multiplexed IN-14s @166-170v? >Date: Fri, 21 Jan 2011 15:58:00 -0800 (PST) > >>Yep, it was a combination of the multiplexing and a problem with the >>anode transistors. It turns out, having a small delay after turning >>off the anodes is important. I already had a few µs between turning >>the anodes off and back on for my shift register write functions, >but >>I needed to add what I believe was an extra 100 clock cycles >(12.5us) >>or else the MPSA92s would stay partially on and allow just enough >>voltage to pass to cause an "off" bulb to flicker during >multiplexing >>and for the MPSA42s to register positive on my DMM. Now it's 100% >>contrast, no flickering at all. Very nice looking. >> >>On Jan 21, 1:35 pm, "M.J.Sangster" <[email protected]> >>wrote: >>> You would read a lower voltage because of the PWM, I believe it is >an >>> average value you are seeing. A scope would show the proper value. >Or >>> you could just slow down the PWM to maybe 2 seconds on, then your >>> meter would show the proper value. >>> >>> - Michael Sangster >>> >>> On Jan 21, 12:00 pm, will <[email protected]> wrote: >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> > Now, my only concern is that my DMM only measures around 110 >volts >>> > between the +voltage supply and the cathode transistors, even >though >>> > there is 170v between +voltage and ground. I'll have to do some >more >>> > testing, but it looks like for some reason the transistor >collectors >>> > are hovering at about 50v... Maybe they just "seem" this way >because >>> > of the PWM? >> >>-- >>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. >> >> $4.95/mo. National Dialup, Anti-Spam, Anti-Virus, 5mb personal web space. 5x faster dialup for only $9.95/mo. No contracts, No fees, No Kidding! See http://www.All2Easy.net for more details! -- 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.
