I'm planning a similar approach with the HP5245L, but instead I will run the counter with a 10-second gate. The gate signal is an *output* from the counter, and while the signal is active, it just acts like a regular counter. So, all I need to do is wait for gate to go active, send a stream of pulses (up to 235,959 of them), and they will display the time.
The odd thing about the 5245 is that the display is on while counting; annoying if you are measuring frequency but just what you need for a clock. After the initial count is displayed, which is pretty fast at 50Mhz (less than 5msec), the next 9+ seconds only require a single pulse to advance the seconds *in most cases*. When there is a rollover for the next minute, you need to send 41 pulses so that xx:x1:59 becomes xx:x:2:00 . Similar exceptions for ten-minute, hours, etc. At midnite, this trick wont work so you may as well flood the device with an erratic burst of pulses to make most of the digits roll. Since a 50Mhz pulse-output is too fast for a cheap microcontroller, it will be done from an FPGA. Of course I wont keep this thing running 24/7 because of the noise and wasted electricity. But at least I will get more usage out of th3 5245L. On Thursday, June 13, 2024 at 7:23:51 AM UTC-7 Adrian Godwin wrote: > Interesting idea. > I'd speculate that the accuracy problem where the counter failed to see > some pulses is perhaps a synchronization problem. If the pulse-counting > method worked by generating a variable number of pulses at 240kHz then they > should always be visible to the counter as long as that's within it's > range. But if the gate period of the counter didn't coincide with the > gating of the pulses at the generator, you would get variable results. And > there's no obvious way to make them synchronise without stop/start signals. > > > On Thu, Jun 13, 2024 at 3:04 PM Paul Andrews <[email protected]> wrote: > >> Why not both? Here is my partially successful attempt to display the time >> on a frequency counter by generating the correct frequency that would >> result in the time being shown in the frequency counter. I had forgotten >> about this until I read this thread: >> >> >> https://www.nixies.us/2018/03/25/display-the-time-on-an-old-frequency-counter/ >> >> On Thursday, June 13, 2024 at 5:53:32 AM UTC-4 Adrian Godwin wrote: >> >>> I much prefer Nixies in functional equipment rather than for their own >>> sake. And while displaying them in a clock is fine, there are other types >>> of clock to cherish too, leading to a loss of space. And since I can build >>> a clock myself, other functionality is attractive (admittedly I wouldn't >>> pay $300). >>> >>> It's a pity there aren't a lot of devices other than counters and DVMs >>> to find - I already have Philps, Racal and Avo examples. I'd like to find a >>> nixie-based measurement system such as a Heidenheim. >>> Are there any other types of instruments that were made ? >>> >>> >>> On Thu, Jun 13, 2024 at 2:03 AM <[email protected]> wrote: >>> >>>> Re: [neonixie-l] A bit $teep for a DMM >>>> On Wed, Jun 12, 2024 at 11:57 AM Mac Doktor <[email protected]> >>>> wrote: >>>> >>>>> What makes this DMM so valuable? There are only four tubes to yank >>>>> out: >>>>> >>>>> https://www.ebay.com/itm/405017664588 >>>>> >>>>> >>>>> It is a FLUKE, you would only Yank the tubes to clan the pins and >>>>> remove the dust from the sockets... then reassemble carefully and bow >>>>> down >>>>> in Veneration. >>>>> >>>> -- >>>> >>> You received this message because you are subscribed to the Google >>>> Groups "neonixie-l" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to [email protected]. >>>> >>> To view this discussion on the web, visit >>>> https://groups.google.com/d/msgid/neonixie-l/194ac98d77051b3026a5ca51c003969b%40zeusprune.ca >>>> >>>> <https://groups.google.com/d/msgid/neonixie-l/194ac98d77051b3026a5ca51c003969b%40zeusprune.ca?utm_medium=email&utm_source=footer> >>>> . >>>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "neonixie-l" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> > To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/b082f74b-146c-48b7-aa06-f325bbceec92n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/neonixie-l/b082f74b-146c-48b7-aa06-f325bbceec92n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/2fdbf720-532c-4590-b187-0fa16e79a999n%40googlegroups.com.
