I tried Rk at 12k and 22k and it is still erratic. Next I went back to full wave and connected it to my display chassis that runs from a PIC that counts at various speeds. I see the circuit only counts slowly but at 10/sec it fails. No flickering, it just does not count. I changed the capacitor to the other side of Rk and it works perfectly. I can't believe it is a typo carried through three documents but companies have been known to intentionally place errors to cause grief to anyone trying to steal their designs. This circuit works. [image: 8453 Circuit.jpg]
On Friday, February 12, 2021 at 12:47:29 PM UTC-5 Dekatron42 wrote: > Thanks, I've never looked at that particular datasheet previously, only > the Philips ones even though I have a few Amperex stamped Z550M's. > > In this document: https://www.dos4ever.com/Z550M/Z550M2.pdf (a somewhat > clearer PDF can be downloaded here: > http://www.tube-tester.com/sites/nixie/dat_arch/Z550M_2.pdf) there is a > paragraph on "Supply voltage" on page 120 where they mention a minimum > repetition frequency of 80 pulses per second as a minmum for proper > operation - perhaps that is the reason why it doesn't work as well on just > half wave rectification. Maybe Amperex had some specially made to be able > to drive them at 117 VAC @ 60Hz? > > /Martin > > On Friday, 12 February 2021 at 17:56:07 UTC+1 [email protected] wrote: > >> Martin; See attached for data sheet. I have tried different capacitors. >> They make no difference for either full wave or half wave - full wave >> always works with no indication of problems and half wave flickers all over >> the place and never works (unless I move the capacitor connection). >> >> Bill van Dijk: I am in Canada, 60 Hz. Control grid?? See data sheet >> attached. >> >> I was hoping someone else would have tried these circuits. I have used a >> 'scope to check the various signals and they look fine. >> >> On Fri, Feb 12, 2021 at 9:06 AM Dekatron42 <[email protected]> wrote: >> >>> Which datasheet do you use? I only have information with the full wave >>> rectifier. >>> >>> What happens if you use a 470nF or 1uF capacitor with the half wave >>> rectifier? I made some quick LTSpice simulations which shows that a higher >>> capacitor might work as the voltage seems to fall low enough between each >>> period, but only real tests can show if that works properly. >>> >>> /Martin >>> >>> On Friday, 12 February 2021 at 14:13:47 UTC+1 [email protected] wrote: >>> >>>> Hi Martin, I changed the circuit back to halfwave using a single diode >>>> from the bridge rectifier and changing the capacitor. This was absolute >>>> minimum change without moving anything else. Back came the >>>> erratic flashing. So it's not the diode. It just does not like half wave. >>>> My circuits are direct copies from the data sheet. >>>> Peter >>>> >>>> On Thu, Feb 11, 2021 at 5:21 PM Dekatron42 <[email protected]> >>>> wrote: >>>> >>>>> Nice that it works! >>>>> >>>>> My understanding is that they need rectified AC, with just a little >>>>> smoothing so as not to make it a pure DC voltage, as they extinguish >>>>> during >>>>> the portion of the voltage when it is to low to maintain the glow, and >>>>> they >>>>> are re-ignited when the voltage rise again as long as a trigger electrode >>>>> has the correct voltage to initiate a glow, much like a thyratron. >>>>> >>>>> Maybe you can find the reason for it working now compared to earlier >>>>> failures if you check the voltage across the Anode-Cathode-Ignition >>>>> electrode with an oscilloscope? >>>>> >>>>> I've also had some problems with CMOS ic's when I have had poor, or >>>>> no, connection to VCC/GND on the power pins - the circuit worked quite >>>>> well >>>>> until I touched some pins. >>>>> >>>>> /Martin >>>>> >>>>> On Thursday, 11 February 2021 at 21:50:49 UTC+1 [email protected] >>>>> wrote: >>>>> >>>>>> I have solved the problem but I don't understand why. >>>>>> Having tried all the suggestions except this, I went to a full wave >>>>>> rectifier. It is not quite the same as the data sheet but does the same >>>>>> thing. >>>>>> It also has the capacitor connected per the data sheet, the same as >>>>>> my half wave circuit that did not work. >>>>>> This is rock solid with no indication of any other flickering. I am >>>>>> using the first (worst) tube. Touching the glass has no effect. >>>>>> Apparently the tube does not like half wave. Perhaps it was my 1N4007 >>>>>> diode? They can switch too fast and maybe it needed a snubber. >>>>>> I also tried DC from a variable regulated power supply (HP 6448B up >>>>>> to 600 [email protected] amp, and no, I did not go that far). That locked the >>>>>> display on one digit. The data sheet says it needs rectified line, not >>>>>> DC. >>>>>> I am running my tests from an HP supply for the 5v and an isolation >>>>>> transformer driven by a Variac for the AC so I have full control of all >>>>>> voltages. >>>>>> This is my final schematic. It is driven by a PIC with parallel >>>>>> connectors for each display. I used a PIC to generate the BCD because >>>>>> CMOS >>>>>> would not drive the three 74141 for the Nixies. The PIC counts up and >>>>>> down >>>>>> at varying speeds which would have been more difficult with CMOS. >>>>>> [image: 8453 Circuit.jpg] >>>>>> >>>>>> >>>>>> >>>>>> On Thu, Feb 11, 2021 at 10:33 AM Dekatron42 <[email protected]> >>>>>> wrote: >>>>>> >>>>>>> Touching the glass means that you get a capacitive coupling which >>>>>>> will upset them somewhat, there was a special socket made for this by >>>>>>> Philips which has a partial metal screen surrounding the tube. The >>>>>>> socket >>>>>>> is nicknamed "der Kuss" , "The kiss", due to its form. I couldn't find >>>>>>> a >>>>>>> photo on the Internet now but I know it exists as I have some in my >>>>>>> storage >>>>>>> and in an instrument that uses them. That instrument is called PW4261 >>>>>>> Timer, some photos of the externals can be found on the Internet. On >>>>>>> this >>>>>>> socket all of the resistors are mounted flush to the pins to minimize >>>>>>> the >>>>>>> distance, but the capacitors and power supply is mounted some 40cm from >>>>>>> the >>>>>>> tubes themselves, likewise there are long wires to the drivers. >>>>>>> >>>>>>> You can also have a look at the manual for the PW4231 which I >>>>>>> scanned that can be downloaded from here: >>>>>>> https://frank.pocnet.net/other/sos/Philips_PW4232.pdf if that can >>>>>>> help you with the voltages for the drivers. >>>>>>> >>>>>>> /Martin >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Thursday, 11 February 2021 at 15:50:55 UTC+1 [email protected] >>>>>>> wrote: >>>>>>> >>>>>>>> I meant dekatron in my last reply to gregebert. >>>>>>>> I have 3 of these tubes, all apparently new (NOS). >>>>>>>> Per your suggestion I tried the other two. One is almost perfect >>>>>>>> but flashes the 2 a bit when 8 is selected. The third is perfect >>>>>>>> unless I >>>>>>>> hold the tube in my fingers by the glass where I get lots of random >>>>>>>> flashing. >>>>>>>> Remember that the really bad one works perfectly with the capacitor >>>>>>>> moved as I mentioned. I don't know if touching the glass affects it. >>>>>>>> More later, I will be away this morning. >>>>>>>> Peter. >>>>>>>> >>>>>>>> On Thu, Feb 11, 2021 at 2:10 AM Dekatron42 <[email protected]> >>>>>>>> wrote: >>>>>>>> >>>>>>>>> Have you tried the circuit in the J.B Dance book below? Here they >>>>>>>>> use a center tapped transformer and also a much lower value >>>>>>>>> capacitor, only >>>>>>>>> 33nF versus 250nF in your circuit - I've only evere seen 33nF used in >>>>>>>>> real >>>>>>>>> instruments using these indicators. >>>>>>>>> >>>>>>>>> Quite a few of the Z550M/ZM1050 are broken internally, I have a >>>>>>>>> box of them, and that seems to be due to the welding of the internal >>>>>>>>> parts >>>>>>>>> coming loose when shaken or hit hard (the same problem exists with >>>>>>>>> the >>>>>>>>> B9012/NL9012 tubes - I have a few broken ones of those too with >>>>>>>>> internal >>>>>>>>> pieces that have come loose) - sometimes you can hear these loose >>>>>>>>> pieces if >>>>>>>>> you shake the tube very carefully close to your ear. What usually >>>>>>>>> happens >>>>>>>>> is that a rather large round center piece comes loose and in the >>>>>>>>> worst case >>>>>>>>> shortens some of the electrodes but usually only makes it hard or >>>>>>>>> impossible to get all digits to light up poperly and some of them >>>>>>>>> trigger >>>>>>>>> easier than others due to the distances between electrodes are >>>>>>>>> differing, >>>>>>>>> shaking the tube a little moves that effect around so other digits >>>>>>>>> will >>>>>>>>> start to work and vice versa. >>>>>>>>> >>>>>>>>> /Martin >>>>>>>>> >>>>>>>>> [image: JBDance-Z550M.JPG] >>>>>>>>> >>>>>>>>> On Thursday, 11 February 2021 at 06:02:24 UTC+1 gregebert wrote: >>>>>>>>> >>>>>>>>>> If you have an isolation transformer, can you put a scope on the >>>>>>>>>> cathode line to verify the ripple is not excessive ? Rk and Ck >>>>>>>>>> create an RC >>>>>>>>>> filter around 77Hz, and the line is 50-60Hz, so there could be some >>>>>>>>>> ripple. >>>>>>>>>> >>>>>>>>>> On Wednesday, February 10, 2021 at 8:26:51 PM UTC-8 >>>>>>>>>> [email protected] wrote: >>>>>>>>>> >>>>>>>>>>> I tried varying it with absolutely no effect. It runs perfectly >>>>>>>>>>> at 5v with the capacitor moved to the other side of the resistor. >>>>>>>>>>> However I >>>>>>>>>>> was clocking slowly. It may not run at spec speed. I seem to >>>>>>>>>>> remember >>>>>>>>>>> reading of using 5 to 8 volts for the logic. >>>>>>>>>>> The data sheet shows the following which I'm inclined to >>>>>>>>>>> believe. I will try Ck directly on the pins tomorrow. Someone must >>>>>>>>>>> have tried this circuit. >>>>>>>>>>> [image: 8453 Cct.JPG] >>>>>>>>>>> >>>>>>>>>>> On Wed, Feb 10, 2021 at 11:12 PM gregebert <[email protected]> >>>>>>>>>>> wrote: >>>>>>>>>>> >>>>>>>>>>>> I suspect the differential voltage between lit vs non-lit >>>>>>>>>>>> numerals is too low. The CMOS device is basically driving grids to >>>>>>>>>>>> determine which cathode will be illuminated. I've seen similar >>>>>>>>>>>> behavior >>>>>>>>>>>> with an A-101 dekatron. What voltage are you using for VDD ? Is it >>>>>>>>>>>> 8V as >>>>>>>>>>>> indicated on the schematic, or a more-conventional 5V ? >>>>>>>>>>>> >>>>>>>>>>>> On Wednesday, February 10, 2021 at 7:22:25 PM UTC-8 >>>>>>>>>>>> [email protected] wrote: >>>>>>>>>>>> >>>>>>>>>>>>> I think you are wrong. The literature explains this tube is >>>>>>>>>>>>> designed to be driven by 5v logic and it does work. The steering >>>>>>>>>>>>> electrodes >>>>>>>>>>>>> are close to the Anode voltage which is grounded and only 5v >>>>>>>>>>>>> pulses (square >>>>>>>>>>>>> waves) are needed. Note all the cathodes are connected together >>>>>>>>>>>>> internally. >>>>>>>>>>>>> I got to thinking about the C1 position. The data sheet shows >>>>>>>>>>>>> it per my schematic and I can't believe they made that mistake >>>>>>>>>>>>> several >>>>>>>>>>>>> times including the hand drawn notes of the designer. I think >>>>>>>>>>>>> maybe I >>>>>>>>>>>>> needed to have C1 directly on the socket pins and will try that >>>>>>>>>>>>> tomorrow. >>>>>>>>>>>>> Thanks for your interest though but you are thinking Nixie >>>>>>>>>>>>> Tubes, this is a special tube with steering electrodes.. >>>>>>>>>>>>> >>>>>>>>>>>>> >>>>>>>>>>>>> On Wed, Feb 10, 2021 at 9:42 PM chuckrr <[email protected]> >>>>>>>>>>>>> wrote: >>>>>>>>>>>>> >>>>>>>>>>>>>> That schematic is so wrong in so many ways. You need high >>>>>>>>>>>>>> voltage transistors operating the tube cathodes. >>>>>>>>>>>>>> >>>>>>>>>>>>>> You need high resistance drving the transistor bases. You >>>>>>>>>>>>>> need a buffer such as 4049 or 4050 driving the >>>>>>>>>>>>>> >>>>>>>>>>>>>> resistor, which in turn drives the transistor base. Only >>>>>>>>>>>>>> then would I dare to use the 4028....to operate the buffer, >>>>>>>>>>>>>> which in turn >>>>>>>>>>>>>> operates the >>>>>>>>>>>>>> >>>>>>>>>>>>>> transistor base via appropriate high resistance. That is the >>>>>>>>>>>>>> only sure fire way I know of to attain noise-free performance >>>>>>>>>>>>>> from CMOS >>>>>>>>>>>>>> logic >>>>>>>>>>>>>> >>>>>>>>>>>>>> driving cold cathode tubes. That schematic there is a noisy >>>>>>>>>>>>>> deal. >>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>>> >>>>>>>>>>>>>> ---- Original Message ---- >>>>>>>>>>>>>> From: "peter bunge" <[email protected]> >>>>>>>>>>>>>> Sent: 2/10/2021 8:15:21 PM >>>>>>>>>>>>>> To: "neonixie-l" <[email protected]> >>>>>>>>>>>>>> Subject: [neonixie-l] 8453/Z550M erratic >>>>>>>>>>>>>> >>>>>>>>>>>>>> Using the schematic from the data sheet >>>>>>>>>>>>>> [image: 8453 Circuit.jpg] >>>>>>>>>>>>>> This works with the count moving around but other numbers >>>>>>>>>>>>>> flash erratically, especially close to the number that is >>>>>>>>>>>>>> supposed to be >>>>>>>>>>>>>> lit. >>>>>>>>>>>>>> *When I moved the bottom of C1 to the other side of R1 it >>>>>>>>>>>>>> works perfectly. It is rock steady and does not care about line >>>>>>>>>>>>>> voltage or >>>>>>>>>>>>>> the 5v supply (shown above as 8v but used at 5v)* >>>>>>>>>>>>>> If this is an error it is continued through all the >>>>>>>>>>>>>> documentation and is consistent. Changing the value of C1 up and >>>>>>>>>>>>>> down by 10 >>>>>>>>>>>>>> had little effect but a smaller C1 helps a bit. My Rst are all >>>>>>>>>>>>>> directly on >>>>>>>>>>>>>> the socket pins and the wires are all about 5 inches long. >>>>>>>>>>>>>> I have varied the line voltage with little effect. >>>>>>>>>>>>>> Any suggestions??? >>>>>>>>>>>>>> >>>>>>>>>>>>>> -- >>>>>>>>>>>>>> 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/b996ef0b-edbb-4c77-8ec1-57255dd58a82n%40googlegroups.com >>>>>>>>>>>>>> >>>>>>>>>>>>>> <https://groups.google.com/d/msgid/neonixie-l/b996ef0b-edbb-4c77-8ec1-57255dd58a82n%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/202102101842701.SM05295%40ADT-IM1 >>>>>>>>>>>>>> >>>>>>>>>>>>>> <https://groups.google.com/d/msgid/neonixie-l/202102101842701.SM05295%40ADT-IM1?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/9543e23e-ebb0-46e7-8624-ddcf4a843667n%40googlegroups.com >>>>>>>>>>>> >>>>>>>>>>>> <https://groups.google.com/d/msgid/neonixie-l/9543e23e-ebb0-46e7-8624-ddcf4a843667n%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/7085da7d-27dd-46f3-9bba-9e2d369dcc4fn%40googlegroups.com >>>>>>>>> >>>>>>>>> <https://groups.google.com/d/msgid/neonixie-l/7085da7d-27dd-46f3-9bba-9e2d369dcc4fn%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/ad3deb14-52ce-4b11-b048-dd6dea83bdban%40googlegroups.com >>>>>>> >>>>>>> <https://groups.google.com/d/msgid/neonixie-l/ad3deb14-52ce-4b11-b048-dd6dea83bdban%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/dcd99e19-3b9c-406c-8057-d69f1547ce03n%40googlegroups.com >>>>> >>>>> <https://groups.google.com/d/msgid/neonixie-l/dcd99e19-3b9c-406c-8057-d69f1547ce03n%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/93f9a715-47dd-4f8b-8fd4-89e03e0bb06bn%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/neonixie-l/93f9a715-47dd-4f8b-8fd4-89e03e0bb06bn%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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