I like both methods. Multiplexing does save on chips and complexity of the circuit board. Also, requires less power.
- Michael http://www.coldwarcreations.com On Jan 22, 6:18 pm, "chuck richards" <[email protected]> wrote: > 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 athttp://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! > Seehttp://www.All2Easy.netfor 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.
