thanks it sounds like fun my kids would love doing that mike
On Sep 30, 1:06 pm, Adam Jacobs <[email protected]> wrote: > Very well put, John. I was thinking along these lines as well. You don't > need to have a nixie to start a nixie clock project. In fact, the nixie > can be the very last component. You might even have a stage with > 7-segment LED's and 7-segment BCD drivers to get your clock code up and > running. One could replace the 7-segment drivers and LED's with 74141's > and nixies at a later stage, once the BCD and blanking was working > correctly. > > -Adam W7ATJ (soon AJ9D) > > On 9/30/2011 6:41 AM, John Rehwinkel wrote: > > > > > > > > >> Hi mike, you might have considered this and rejected it, but how about > >> doing your first clock with numitrons? They don't require the elevated > >> voltage and small ones can be bought off ebay cheaply. > > Another idea is to go ahead and use a 74141 type drivers with an ordinary > > five volt supply and ten LEDs with a 1k anode > > resistoror or even small incandescent lamps (you can chop up a holiday > > light string to get cheap bulbs and sockets). > > This could be done cheaply or even free. A dead ethernet hub will > > generally get you a five volt supply and several > > LEDs. You can get a 74141 chip for a buck or so. You can start lighting > > LEDs even before you round up a driver chip. > > > Once you have that, you and your kids can manually tie the various input > > pins to the positive supply or ground, > > and see how the chip works to drive a single output at a time. > > > You could proceed forward in two ways. You could add a microprocessor and > > work out how to program the micro > > and light up the LEDs or bulbs. Or you could try to scrounge up a high > > voltage supply and some small neon bulbs. > > Supply the neons with your HV supply, and change the anode resistor to 470k > > or so, and your 74141 will light them > > instead of the LEDs. > > > Then, when you find a nixie tube, you can just swap it for the neon bulbs, > > and change the anode resistor appropriately, > > still using the same 74141 chip to drive it. > > > This way, you have something up and running soon and cheaply (I find this > > the best encouragement), you start with > > safe low voltage, and you can learn about microprocessors a step at a time. > > > If you add a second 74141 or a pair of anode drivers, you get a two-digit > > display, which is sufficient for getting > > started with a thermometer. You can quickly learn to read a column of ten > > lights (LEDs or neons), or you can > > arrange for them to shine through digit cutouts. This is exactly how the > > display worked in some HP frequency > > counters: > > >http://www.hpmemory.org/wa_pages/wall_a_page_11.htm > > > As you can see, I'm a big fan of getting something working at an early > > stage, doing things on the cheap, and > > electronics in general. > > > - John KG4L -- 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.
