It's an interesting combination those 2 npn transistors. The signal on the base is actually inverted compared to "normal" npn/pnp transistors. When T2, T3, T5 are switched off, the tubes are actually on :-). That's also where your leakage problem comes from if you ask me. You choose 220k resistors, which means the lowest possible anode voltage is half the supply voltage (215V / (220k + 220k)) * 220k = 107.5V. You better choose a lower resistor that goes to the collector of T2, T3, T5 (maybe 100k). This will bring the anode voltage down to about 68V.
I don't have a price yet for my modules, they won't be expensive of course but I need to wait until I have a finished product. Michel On Mar 23, 5:00 am, Imbanon <[email protected]> wrote: > Sorry about that. I thought it was an universal shematic file type, > 'cause they are all .sch > > Here's the pic http://www.mediafire.com/download.php?5903q1ur3inc729 > Cheers > > On Mar 22, 4:14 pm, Adam Jacobs <[email protected]> wrote: > > > > > > > > > Would you mind converting that schematic to some kind of image file? Is > > that an eaglecad file? > > > blanking on the 74141 will cause leakage if the supply voltage is too > > high. Are you using real 74141's or the russian kind? > > From that picture, I'm not sure if that is leakage. > > > -Adam > > > On 3/22/2012 5:19 AM, Imbanon wrote: > > > > Hey all > > > > I found some time to make a schematic. It only shows the two 74141, > > > nixie tubes and anode drivers. > > > I also tried blanking nixies via 74141. I would have never guessed > > > that you meant on hex code, as I am doing this on an arduino :) > > > Blanking nixies with 74141's give me a lot of leaking (or at least I > > > think thats leaking), so I'm not so sure about using this method. But > > > I do think that it's maybe possible to divide the leaking to the rest > > > of the nixies by adding a resistor for each anode, instead of sharing > > > them. See for yourself in the links. > > > >http://www.mediafire.com/download.php?bbx4z4k5vjul56b > > >http://www.mediafire.com/download.php?ym4s96yeusrm9sy > > > > So I guess my next move should be to remove the trimpots, and replace > > > them with actual resistors for each anode. > > > But what should I do with the blanking? To be honest, I would leave > > > the setup as is, because it seems to work fine. But if you guys think > > > I can do something better to get a longer tube life, I will make > > > changes to the schematic immediately. > > > > Thanks! > > > > On Mar 19, 12:04 am, Dylan Distasio<[email protected]> wrote: > > >> I'm very interested in hearing more about this module...Are you saying > > >> you > > >> are having this custom manufactured? If so, how have you found a way to > > >> do > > >> this economically? > > > >> On Sun, Mar 18, 2012 at 6:31 PM, Cobra007<[email protected]> wrote: > > > >>> For my clock I am designing a module as I am not really a fan to use > > >>> these types of old TTL logic. It's a 24 pin module that fits into a > > >>> DIP24 IC socket. It basically mimics the 74141 but has high voltage > > >>> output mosfets (240V) and the 4 inputs can be latched, so you don't > > >>> need extra latches as required by the standard 74141. It also offers a > > >>> blanking input, either by writing 0x0a or using a dedicated pin (which > > >>> is convenient for PWM dimming). It can be interfaced with MCU or > > >>> arduino. > > >>> Michel -- 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.
