Yes, the double pulse situation is the relevant one here - the other two on the datasheet refer to specific valve circuit configurations that were used at that time to generate the guide pulses. Modern components make the job much easier in most ways. The datasheet recommended conditions call for guide pulses of 80V +/- 10V amplitude, negative going, from a baseline of +36V (the guide bias voltage). A swing from +40V to -40V will do the trick just perfectly.
As discussed earlier in the thread, there is quite some latitude around these conditions, particularly for 'new' or lightly used tubes. In my experiment a +25V to -25V swing worked fine, even up to the full spec counting speed once it had woken up a bit from being asleep for decades. But that was a NIB tube. I suspect that your other dekatron has seen more use and/or is more deeply asleep, so for that one you'll maybe have to get closer to the datasheet spec. And maybe start with longer pulses. I'll PM you on a couple of additional details. Jon. On Thursday, February 18, 2021 at 4:00:55 PM UTC bung...@gmail.com wrote: > I found a reference: > http://www.r-type.org/articles/art-132.htm > that explains the difference. So I am using double pulse rather than an > integrated single pulse to get the delay. > The data sheet implies I should be using -80v pulses to drive the rings. I > guess I will up the drive voltage when my optocouplers arrive. I ordered > 80v ones, perhaps I should have ordered the 300v ones. Oh well, another $8 > shipping if I must. > Some useful parts from DigiKey: > MOC8050M-ND optocoupler 80v > SFH619A-ND optocoupler 300v > HM4682-ND Hammond 186C120 transformer to isolate my CRT clock that is live > to line. It has dual primaries and I will see if I can use it backwards to > get two 120v outputs isolated from line (which will only work for 120v > power in Canada/USA) > 497-2344-5-ND ULN2003A 7 segment driver for Vacuum Fluorescent displays, > stepper motors, relays. Observe voltage ratings. There is an 8 transistor > version as well. > Peter > > On Thursday, February 18, 2021 at 10:27:29 AM UTC-5 peter bunge wrote: > >> I tried another Dekatron but I'm not sure what it is, and it doesn't >> work. The glow just flickers back and forth on adjacent elements. >> This tube looks a bit like the GS10C/S but has no markings, has a metal >> base, and the end is domed instead of flat. It fits the same socket and >> appears to have guide rings. >> My high voltage optocouplers don't arrive until this afternoon and I have >> already tried +/- 25v which is 30v above the rating of the optocoupler I am >> using. They have not blown, yet. >> I am trying to understand the data sheet for the GS10C/S, looking at >> recommended operating conditions: >> What does double pulse drive-amplitude mean? >> What does Integrated pulse drive amplitude mean? >> I just finished re-reading Ronald Dekker's description of how it works >> and his experiments. >> Peter >> >> On Thu, Feb 18, 2021 at 3:09 AM Jon <deka...@nomotron.com> wrote: >> >>> Good to hear - another successful neon spinny thing! >>> >>> Jon. >>> >>> On Wednesday, February 17, 2021 at 10:55:59 PM UTC bung...@gmail.com >>> wrote: >>> >>>> I tried my new circuit with the optocouplers using 270k for R5 & R6 and >>>> 1k for R3 & R4. >>>> It works within the limits of +0v and about -22v. It is interesting >>>> that the other circuit did not work for low + bias. It must be the slower >>>> positive edge as someone mentioned. I will use about +30 and -30v, >>>> whatever >>>> the rectified transformer gives. >>>> This is my preliminary software. It only counts up at present from 0 to >>>> 9 fast (10Hz) slowing down to 1Hz then repeating. The delay between the >>>> steering pulses depends on the speed so at 1 Hz you can actually see every >>>> pin lit. I thought it a waste to not see them. I have not fully tried this >>>> software, only a Dekatron test version, so if there are errors please >>>> forgive me. There is a BCD version that also works. I may add a "Spinner" >>>> between 0 to 9 counts in place of the 2 second delay, 1 second forwards >>>> and >>>> 1 second backwards. >>>> // main loop >>>> while (1) // loop endlessly >>>> { >>>> for(j=1;j<=10;j++) // sets the delays >>>> { >>>> for(i=0;i<=9;i++) // the BCD digit displayed (Nixies, >>>> etc) >>>> { >>>> // generate clock and BCD >>>> output_high(pin_C4); // high for 10 uS >>>> delay_us(10); >>>> output_low (pin_C4); // end pulse >>>> portC = i; // output BCD >>>> // Dekatron clocking >>>> output_high(pin_A5); // steering ring 1 >>>> delay_ms(j*50); >>>> output_high(pin_A4); // steering ring 2 >>>> delay_ms(j*50); >>>> output_low (pin_A5); >>>> delay_ms(j*50); >>>> output_low (pin_A4); >>>> // period of sequence >>>> delay_ms(j*100); // set period >>>> } //end for i loop >>>> delay_ms(2000); // wait 2 seconds after each 0 to 9 count >>>> } //end for j loop >>>> } //end of endless while loop >>>> } // end of main function >>>> >>>> On Wed, Feb 17, 2021 at 4:00 PM Jon <deka...@nomotron.com> wrote: >>>> >>>>> No hard figures - it's dependent on a bunch of factors; principally >>>>> manufacturing quality, how you use the tube, operating temperature and >>>>> gas >>>>> fill. If you keep the operating current within spec and preferably at the >>>>> lower end, avoid the tube getting heated from its surroundings and above >>>>> all else keep the glow moving around all of the electrodes, they will >>>>> last >>>>> a seriously long time. The electrical properties will change gradually - >>>>> the maintaining voltage rises and the latitude around the voltages >>>>> required >>>>> for reliable stepping decreases. So you were absolutely right to point >>>>> out >>>>> the importance of taking note of these elements of the spec when >>>>> designing >>>>> - you can get away with a lot on a NIB tube, but progressively less with >>>>> age. Of course if the application requires clear glass to see the lovely >>>>> glow, then the tube may reach end of its useful life in that application >>>>> as >>>>> sputtering gradually obscures the view, and that may happen well before >>>>> it >>>>> ceases to step reliably. >>>>> >>>>> I'm not surprised by gregebert's description of his A101 - his >>>>> application sounds like a great recipe for a long dekatron life. The slow >>>>> speed ones are tough as anything and they love to work! Just for context, >>>>> I >>>>> believe that the large majority of dekatrons working in the stores of the >>>>> WITCH today are from the original complement of tubes the machine was >>>>> built >>>>> with at the start of the 1950s. Can't formally prove it of course, but >>>>> the >>>>> date codes are consistent with that. Also, as we've noted before on other >>>>> Russian glow tubes, the guaranteed life spans on the datasheets are >>>>> ridiculously conservative if the tubes are treated well. The A101 >>>>> datasheet >>>>> gives a 1000 hour life - his A101 has done 70x that! I have a similar >>>>> experience with my IN9 clock - the prototype unit is still going strong >>>>> on >>>>> its original tubes after 120K hours - datasheet life is 1K hours. >>>>> >>>>> Note that we're talking here about use-related life limitation - the >>>>> death in storage of the high-speed dekatrons is a whole different topic. >>>>> >>>>> Jon. >>>>> >>>>> On Tuesday, February 16, 2021 at 8:49:07 PM UTC Dekatron42 wrote: >>>>> >>>>>> No, unfortunately not, no hard figures - maybe Jon has. I've only >>>>>> read in some books about dekatron construction (neon tube construction >>>>>> in >>>>>> general where dekatrons are shown as special variations) that they have >>>>>> similar lifespans compared to small neon lamps but that the complex >>>>>> design >>>>>> complicates the failure modes/rate and also that keeping >>>>>> currents/voltages >>>>>> within the values specified in the datasheet will guarantee that they >>>>>> work >>>>>> as long as possible. >>>>>> >>>>>> It depends on when you say a dekatron fails, it can get a silvery >>>>>> finish on the glass so you almost can't see the glow but it still works >>>>>> and >>>>>> it can fail a lot earlier than that due to internal flash-overs due to >>>>>> sputtering onto the ceramic material which means a current can flow in >>>>>> this >>>>>> sputtered material as the distance is shorter there compared to other >>>>>> paths >>>>>> (I have a few dekatrons with that failure and of course a few with a >>>>>> silvery look). >>>>>> >>>>>> I have to count my dekatrons one day to see if I have enough to build >>>>>> a second Harwell WITCH..... ;) :) >>>>>> >>>>>> /Martin >>>>>> >>>>>> On Tuesday, 16 February 2021 at 17:16:07 UTC+1 gregebert wrote: >>>>>> >>>>>>> *Martin* - Do you know how long dekatrons last ? I have an A-101 >>>>>>> running as a spinner in one of my clocks, and it's been going 60RPM >>>>>>> 24/7 >>>>>>> for almost 8 years with no signs of degradation. I use 30k dropping >>>>>>> resistors at the cathodes, and the current is right at the spec value >>>>>>> of >>>>>>> 450uA, so that gives about 15V for "steering", and the driving waveform >>>>>>> is >>>>>>> 3-phase with overlap. I >>>>>>> >>>>>>> On Tuesday, February 16, 2021 at 4:15:05 AM UTC-8 Dekatron42 wrote: >>>>>>> >>>>>>>> There is one more dimension to think about when running a dekatron >>>>>>>> and that is that over time it will degrade due to sputtering affecting >>>>>>>> the >>>>>>>> electrodes and to maintain a correct counting when it ages you should >>>>>>>> keep >>>>>>>> the voltages as described in the datasheet, especially the guide and >>>>>>>> bias >>>>>>>> voltages as those are needed when the dekatron nears its end of life - >>>>>>>> it >>>>>>>> is the same effect that is in play if you want to raise a dekatron >>>>>>>> from the >>>>>>>> dead if it has been heavily used or just stored for a very long time >>>>>>>> without use, raise the bias/pulse voltages and sometimes the anode >>>>>>>> voltage >>>>>>>> to surpass the effects of the sputtering - effectively increasing the >>>>>>>> current flow between the anode and the guides/cathodes. >>>>>>>> >>>>>>>> So even if dekatrons work at other voltages you will see the >>>>>>>> effects of lower/incorrect voltages when they near their end of life, >>>>>>>> this >>>>>>>> has been described in older litterature where the internals of >>>>>>>> dekatrons >>>>>>>> has been disected in detail - you might just need some 10V below the >>>>>>>> glowing cathode to move the glow on a new dekatron but as it ages it >>>>>>>> will >>>>>>>> stop working at that voltage. >>>>>>>> >>>>>>>> /Martin >>>>>>>> >>>>>>>> On Tuesday, 16 February 2021 at 00:53:36 UTC+1 bung...@gmail.com >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Those values were left over from the 5v circuit. I was more >>>>>>>>> concerned with the level shifting from the PIC at 0 to +5v. >>>>>>>>> Peter >>>>>>>>> >>>>>>>>> On Mon, Feb 15, 2021 at 6:48 PM Jon <deka...@nomotron.com> wrote: >>>>>>>>> >>>>>>>>>> I'd had a similar thought about increasing the bias resistors - >>>>>>>>>> it's not necessary to run so much current (5mA) through that part of >>>>>>>>>> the >>>>>>>>>> circuit. >>>>>>>>>> >>>>>>>>>> OK, so your proposed conditions are that the dekatron will see >>>>>>>>>> are 400V anode to main cathodes; guides swinging from +25V to -25V >>>>>>>>>> with >>>>>>>>>> respect to main cathodes. Tube current will be about 345uA. >>>>>>>>>> I've replicated these on my dekatron tester using a nice NIB >>>>>>>>>> GS10C/S as the test subject and can confirm that they do work - the >>>>>>>>>> tube >>>>>>>>>> stepped fine up at speeds up to over 4kpps once I'd woken it up a >>>>>>>>>> bit. >>>>>>>>>> >>>>>>>>>> Caveats: >>>>>>>>>> 1) I only tried one tube. >>>>>>>>>> 2) My circuit is rather different to yours so although the static >>>>>>>>>> voltages are the same, the pulse shapes are almost certainly >>>>>>>>>> different. And >>>>>>>>>> we didn't even talk yet about pulse durations, so I've no idea what >>>>>>>>>> your >>>>>>>>>> PIC is spitting out. But as long as you're not trying to cut things >>>>>>>>>> too >>>>>>>>>> fine, there's lots of latitude to find patterns that work. Keep >>>>>>>>>> things >>>>>>>>>> north of 100us per phase and you'll be fine unless you've got a >>>>>>>>>> really >>>>>>>>>> reluctant tube. >>>>>>>>>> 3) I was running at slightly lower current (300uA) so you've >>>>>>>>>> probably got a bit more margin for speed than I had. Recommended >>>>>>>>>> operating >>>>>>>>>> conditions are 325uA +/- 20%, so we're both inside that range. But a >>>>>>>>>> little >>>>>>>>>> more rather than less current is useful when pushing higher speeds. >>>>>>>>>> I'm >>>>>>>>>> guessing though that you're looking for a much slower stepping speed >>>>>>>>>> for >>>>>>>>>> this application though. >>>>>>>>>> >>>>>>>>>> If you've not already done so, I'd definitely second Martin's >>>>>>>>>> recommendation to take a look at Michael Moorrees' dekatron work (he >>>>>>>>>> looks >>>>>>>>>> in here from time to time too). He used a couple of elegant design >>>>>>>>>> tricks >>>>>>>>>> which simplify the interfacing of dekatrons to modern electronics / >>>>>>>>>> microcontrollers - I've followed his approach in pretty much all the >>>>>>>>>> stuff >>>>>>>>>> I've built and it works a treat. Not to say that other approaches >>>>>>>>>> aren't >>>>>>>>>> equally useful too of course. >>>>>>>>>> >>>>>>>>>> Jon. >>>>>>>>>> >>>>>>>>>> On Monday, February 15, 2021 at 9:39:13 AM UTC Dekatron42 wrote: >>>>>>>>>> >>>>>>>>>>> I'd raise the resistance to at least some 100k for the two bias >>>>>>>>>>> resistors R5 & R6 in your diagram above. >>>>>>>>>>> >>>>>>>>>>> I'd also use the correct bias voltage and just use an MPSA42 >>>>>>>>>>> with its emitter to common ground for the driver to simplify the >>>>>>>>>>> circuit as >>>>>>>>>>> Ronald Dekker and Michael Moorrees with their dekatron circuits. >>>>>>>>>>> >>>>>>>>>>> Different dekatrons need different bias and pulse voltages on >>>>>>>>>>> the guide electrodes to count properly so accomodating for those >>>>>>>>>>> requiremenst will remove a lot of problems and keep down the fault >>>>>>>>>>> finding >>>>>>>>>>> time. >>>>>>>>>>> >>>>>>>>>>> /Martin >>>>>>>>>>> On Monday, 15 February 2021 at 03:05:12 UTC+1 bung...@gmail.com >>>>>>>>>>> wrote: >>>>>>>>>>> >>>>>>>>>>>> You are absolutely right. 5v was not high enough despite >>>>>>>>>>>> Ronald's and my confirmation that it would work. >>>>>>>>>>>> I am changing to +25v and -25v and will have an optocoupler >>>>>>>>>>>> with the diode driven from the 5v PIC and the transistor at the >>>>>>>>>>>> bottom of >>>>>>>>>>>> the resistor between the two power supplies. It keeps it simple. I >>>>>>>>>>>> have to >>>>>>>>>>>> order the optocoupler because none of my old ones have higher than >>>>>>>>>>>> 30 v >>>>>>>>>>>> rating. >>>>>>>>>>>> I will have to think about the extra two power supplies. Maybe >>>>>>>>>>>> I can't avoid them. It will be a few days until I get the parts. >>>>>>>>>>>> Peter >>>>>>>>>>>> [image: Dekatron Circuit.jpg] >>>>>>>>>>>> >>>>>>>>>>>> On Sun, Feb 14, 2021 at 3:18 PM Jon <deka...@nomotron.com> >>>>>>>>>>>> wrote: >>>>>>>>>>>> >>>>>>>>>>>>> Interesting approach - not seen it rigged up quite like that. >>>>>>>>>>>>> Let us know how it goes! >>>>>>>>>>>>> >>>>>>>>>>>>> My immediate question is whether there's a big enough >>>>>>>>>>>>> potential difference between an inactive guide and a main cathode >>>>>>>>>>>>> to get a >>>>>>>>>>>>> reliable transfer forward from a deactivating G2 to the 'next' >>>>>>>>>>>>> main cathode >>>>>>>>>>>>> rather than back to the adjacent recently used G1 - 5V is much >>>>>>>>>>>>> lower than >>>>>>>>>>>>> the datasheet guide bias. Might be OK at slow stepping speeds >>>>>>>>>>>>> with long >>>>>>>>>>>>> guide pulses. Also the leading edge of your guide pulses is going >>>>>>>>>>>>> to be >>>>>>>>>>>>> fairly slow as Q1/2 come out of saturation and the guides are >>>>>>>>>>>>> passively >>>>>>>>>>>>> pulled down to the 'active' voltage. Most guide drive circuits >>>>>>>>>>>>> use a NPN >>>>>>>>>>>>> pull-down to the active state which creates a sharp leading edge >>>>>>>>>>>>> and then a >>>>>>>>>>>>> slower return to the inactive state. >>>>>>>>>>>>> >>>>>>>>>>>>> Jon. >>>>>>>>>>>>> >>>>>>>>>>>>> On Sunday, February 14, 2021 at 7:06:28 PM UTC >>>>>>>>>>>>> bung...@gmail.com wrote: >>>>>>>>>>>>> >>>>>>>>>>>>>> Having finished the Amperex 8453 display I started on my >>>>>>>>>>>>>> Dekatron. Thanks to all for the suggestions. >>>>>>>>>>>>>> I read up on Ronald Dekker's clock project >>>>>>>>>>>>>> https://www.dos4ever.com/decatron/decatronweb.html >>>>>>>>>>>>>> and decided against a direct drive from a 74141 because, >>>>>>>>>>>>>> even if it was practical, it would not look as good as using all >>>>>>>>>>>>>> the pins. >>>>>>>>>>>>>> It would look like the 8453 I just finished except without the >>>>>>>>>>>>>> number mask. >>>>>>>>>>>>>> A few quick experiments showed that a -24v power supply was >>>>>>>>>>>>>> needed for the easiest implementation.. This is my design. I >>>>>>>>>>>>>> will let you >>>>>>>>>>>>>> know if it works. >>>>>>>>>>>>>> >>>>>>>>>>>>>> A PIC drives the circuit: it starts with Q3 off to force a >>>>>>>>>>>>>> start at 1. A high on R3 or R4 is the same as the switches in >>>>>>>>>>>>>> Ron's test >>>>>>>>>>>>>> circuit placing -24v on the guides. As my PIC sends the BCD for >>>>>>>>>>>>>> the other >>>>>>>>>>>>>> displays and clocks the E1T it will generate the sequence to >>>>>>>>>>>>>> advance or >>>>>>>>>>>>>> retard this Dekatron.. >>>>>>>>>>>>>> [image: Dekatron Circuit.jpg] >>>>>>>>>>>>>> >>>>>>>>>>>>> -- >>>>>>>>>>>>> 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 neonixie-l+...@googlegroups.com. >>>>>>>>>>>>> To view this discussion on the web, visit >>>>>>>>>>>>> https://groups.google.com/d/msgid/neonixie-l/62979e37-ef21-46e1-9b7c-45a4c4080238n%40googlegroups.com >>>>>>>>>>>>> >>>>>>>>>>>>> <https://groups.google.com/d/msgid/neonixie-l/62979e37-ef21-46e1-9b7c-45a4c4080238n%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>>>>>>>>>> . >>>>>>>>>>>>> >>>>>>>>>>>> -- >>>>>>>>>> >>>>>>>>> You received this message because you are subscribed to a topic in >>>>>>>>>> the Google Groups "neonixie-l" group. >>>>>>>>>> To unsubscribe from this topic, visit >>>>>>>>>> https://groups.google.com/d/topic/neonixie-l/dQn3tFBYfoc/unsubscribe >>>>>>>>>> . >>>>>>>>>> To unsubscribe from this group and all its topics, send an email >>>>>>>>>> to neonixie-l+...@googlegroups.com. >>>>>>>>>> To view this discussion on the web, visit >>>>>>>>>> https://groups.google.com/d/msgid/neonixie-l/75f258db-83ea-4df3-9d50-52dcaed1461en%40googlegroups.com >>>>>>>>>> >>>>>>>>>> <https://groups.google.com/d/msgid/neonixie-l/75f258db-83ea-4df3-9d50-52dcaed1461en%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 neonixie-l+...@googlegroups.com. >>>>> >>>> To view this discussion on the web, visit >>>>> https://groups.google.com/d/msgid/neonixie-l/bcaa0282-1c44-4b37-9f6f-98845208efecn%40googlegroups.com >>>>> >>>>> <https://groups.google.com/d/msgid/neonixie-l/bcaa0282-1c44-4b37-9f6f-98845208efecn%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 neonixie-l+...@googlegroups.com. >>> >> To view this discussion on the web, visit >>> https://groups.google.com/d/msgid/neonixie-l/3cc6ab77-f4c7-4ae9-8d65-6a60653b7895n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/neonixie-l/3cc6ab77-f4c7-4ae9-8d65-6a60653b7895n%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. 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