A quick Googling of MM5314N and Numitron finds this webpage: http://www.tuberadios.com/numitron/ with schematic that is said to be compliments of Westdave.
/Martin On Tuesday, 7 March 2023 at 16:41:24 UTC+1 Nicholas Stock wrote: > If I'm not mistaken, the clock kit that Martin is referring to is this > one.. > > http://rrsignal.com/projects.htm > > I have the schematic at home somewhere and will dig it out. There is a > dimming mod using a transistor/pot that works quite nicely. Mine has been > running for about 8 years now with no issues..... it uses the MM5314 clock > chip, so no software to be seen and is mains referenced, but keeps > remarkably good time over long periods (it sits next to a few GPS > disciplined clocks). > > Cheers, > > Nick > > On Tue, Mar 7, 2023 at 7:18 AM Batareyka <[email protected]> wrote: > >> There are two ways to solve this problem. >> 1. Software, but as the author of the topic, there is no software and the >> possibility of editing it (I >> I think so), then method number 2 remains. >> 2. The 4511 chip has a wide power supply range from 3-16 volts. Put the >> power regulator and turn it up to 4 volts, which will change the output >> power of the lamp filaments accordingly. >> Checked more than once. >> >> вторник, 7 марта 2023 г. в 17:02:08 UTC+2, [email protected]: >> > Martin, >>> >>> >>> >>> How did you do that? (schematic) >>> >>> >>> >>> Problem with a pot (or any resistor) is that you would need one for each >>> element (7 per tube) since you cannot put one in the common line. Each >>> filament draws about 22mA, so depending on the number displayed, the >>> current would be anywhere between 44 and 154 mA. This would result in >>> different voltage drops depending on the number displayed. It would result >>> in uneven light output. Same reason why you could not use a single current >>> regulator pre tube, but one per filament would be needed. A voltage >>> regulator (such as a simple diode) does not have that disadvantage. >>> >>> >>> >>> Bill v >>> >>> >>> >>> *From:* [email protected] <[email protected]> *On >>> Behalf Of *martin martin >>> *Sent:* Tuesday, March 07, 2023 9:09 AM >>> *To:* [email protected] >>> *Subject:* Re: [neonixie-l] Re: IV-9 numitron lifespan >>> >>> >>> >>> How about this clock I built in the early 80s? 5314 clock chip. I used >>> a 1k pot for dimming. Has been running for many moons now! >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> ~ >>> >>> *[email protected]* >>> >>> >>> >>> >>> >>> On Tue, Mar 7, 2023 at 5:55 AM gregebert <[email protected]> wrote: >>> >>> Under "normal" circumstances, I agree that individual current regulators >>> add a lot of circuitry. The reality is that most tubes are no longer >>> manufactured, so their numbers are dwindling as the price increases, >>> essentially irreplaceable. You wouldn't believe the lengths I went towards >>> protecting NIMO tubes in the clock I'm still working on. >>> >>> >>> >>> I've debated about building a numitron clock, and the route I think I >>> will go with uses LED 'filaments' that are used in retro light bulbs. >>> Filaments scare the heck out of me because they will fail from thermal >>> cycling, but there is no alternative for NIMO and VFD displays. >>> >>> On Monday, March 6, 2023 at 11:35:22 AM UTC-3 [email protected] wrote: >>> >>> Using a current limiter sounds like a LOT of circuitry, 7 times the >>> number of tubes? I simply use a forward biased diode to drop the voltage, >>> about 0.7 for a standard silicon diode, and about 0.3 for a Schottky. That >>> requires only one or perhaps two diodes for the whole set of tubes. Perhaps >>> not as accurate, but definitely a whole lot simpler. >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> *From:* [email protected] <[email protected]> *On >>> Behalf Of *gregebert >>> *Sent:* Monday, March 06, 2023 8:13 AM >>> *To:* neonixie-l <[email protected]> >>> *Subject:* Re: [neonixie-l] Re: IV-9 numitron lifespan >>> >>> >>> >>> Very good info, Moses. >>> >>> >>> >>> From that, I would target the operating current well-below 20mA to >>> prolong the life of the display. You could use an NPN current-limiter >>> (driver) driven from 5V TTL logic. Let me know if you need circuit details, >>> but it's a very simple design (1 NPN + 1 emitter resistor). As a starting >>> point, a 270 ohm emitter resistor will limit current to 16mA. >>> >>> >>> >>> Do you hear any noise with your PWM running at 1600Hz ? If not, I would >>> stick with PWM and not use the NPN driver, as it's not necessary. As long >>> as the PWM cycle-time is shorter than the thermal time-constant of the >>> filament (probably a few milliseconds), you should be fine. I think you can >>> measure the thermal time-constant of the filament with a phototransistor >>> and a scope. Starting at a low PWM frequency, the phototransistor will show >>> fluctuations in the bulb's intensity. As the frequency is increased, you >>> should see the amplitude decrease towards zero. I've never actually done >>> this but I'm pretty sure it will work. You have to use a phototransistor >>> (or photodiode); a CdS photosensor will have too-slow of a response time. >>> >>> On Monday, March 6, 2023 at 2:37:45 AM UTC-3 Moses wrote: >>> >>> The TI CD4511B datasheet lists the lists the *minimum* high level output >>> (at 5v VDD) of 4.1v but typical is 4.55v, maybe others are different? >>> >>> >>> >>> https://www.ti.com/lit/ds/symlink/cd4511b.pdf >>> >>> At 4.55v the segment current on the IV-9 is going to be about 25ma. >>> Typical IV-9 segment current is about 20ma I believe, so that would be a >>> 25% overdrive. >>> >>> >>> >>> I've put up a drive voltage vs segment current table on my site, maybe >>> it's useful to someone: http://www.neonixie.com/IV-9-6D-RR/#tech >>> >>> >>> >>> I settled with powering the tubes in my designs in one of two ways.. >>> 5.0v direct with a recommended PWM of about 65% (the 165 (out of 255) value >>> in the table) OR 5v through a regular silicon diode, dropping the voltage >>> to about 4.2v at the tube and PWM that to 76%. Both result in a segment >>> current of 20ma. Don't know if one or the other is better in regards to >>> lifetime, I was not able to find any official sources of information. I >>> experimented with driving them using a 3.3v regulator.. but at that voltage >>> they were a bit dim. >>> >>> >>> >>> NOTE: The IV-9 datasheet does mention to avoid running the tubes at a >>> frequency between 105 and 1000 Hz, presumably to avoid mechanical >>> resonance. I elected to run them at 1600 Hz. >>> >>> >>> >>> I looked through some of my testing data.. at a segment current of 3mA >>> the segments are visible, 2mA they are "barely visible" and at 1mA I noted >>> them as not visible. Keeping the unlit segments warm with a slight current >>> seems to make the most sense to me. It's all software on my clock so maybe >>> an option for the next revision. >>> >>> >>> >>> That's all I know so far. >>> >>> >>> >>> Regards, >>> >>> -Moses >>> >>> On Saturday, March 4, 2023 at 5:52:05 AM UTC-8 [email protected] >>> wrote: >>> >>> Hi Chris, >>> >>> >>> >>> The numitrons are driven by a 4511 decoder, and according to their data >>> sheets the max. output at that voltage is 4.1 V, so that is well within >>> specification for the tube. Yes, I agree, lowering the voltage even further >>> should increase lifespan. >>> >>> >>> >>> Bill v >>> >>> >>> >>> *From:* [email protected] <[email protected]> *On >>> Behalf Of *Chris >>> *Sent:* Saturday, March 04, 2023 8:19 AM >>> *To:* neonixie-l <[email protected]> >>> *Subject:* [neonixie-l] Re: IV-9 numitron lifespan >>> >>> >>> >>> Hi, >>> >>> While i am not sure for the IV9 numitrons have a look at the DA2300 >>> lifetime expectancy, >>> >>> >>> >>> Basically reducing the voltage increases the life expectancy >>> exponentially. >>> >>> So i usually run my numitrons at 4.5V or lower and have had no issues so >>> far. >>> >>> On Friday, March 3, 2023 at 8:05:48 PM UTC+1 [email protected] wrote: >>> >>> I seem to recall there was some discussion on the life expectancy of >>> IV-9 numitrons some time ago. >>> >>> >>> >>> In 2015 I built a number of clocks with these tubes, and they started >>> failing last year. The clock in the picture is on my bench now, the three >>> good tubes were replaced in November last year. So today all 6 tubes will >>> be replaced. I have replaced all 6 tubes on a few other clocks also. One or >>> more segments will no longer light up, and I do not see any blackening of >>> the glass tube (The black you see in the picture is my permanent marker, s >>> I will not replace the wrong tube when I disconnect the power). >>> >>> >>> >>> The tubes are driven directly from a 4511 chip on a 5V power line. >>> >>> >>> >>> There does not seem to be any order in which they fail, so I do not have >>> the feeling that any of the tubes are significantly impacted by thermal >>> stresses from flashing on and off. I would say based on my experience with >>> them, the expected lifespan is about 7 years of continues use. >>> >>> >>> >>> Bill v >>> >>> -- >>> 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/81b5b7e6-d476-4b83-9a8e-c9d6cc468db9n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/neonixie-l/81b5b7e6-d476-4b83-9a8e-c9d6cc468db9n%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/13ceb519-9b4d-469e-9e03-8d844e317239n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/neonixie-l/13ceb519-9b4d-469e-9e03-8d844e317239n%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/e87e8845-5e21-4b9d-9408-49ee93a3578dn%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/neonixie-l/e87e8845-5e21-4b9d-9408-49ee93a3578dn%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/CAKYv7NTaviwTXv09wHvzZ3mHt5PFK-5GRSRBArjLtmKp78GekQ%40mail.gmail.com >>> >>> <https://groups.google.com/d/msgid/neonixie-l/CAKYv7NTaviwTXv09wHvzZ3mHt5PFK-5GRSRBArjLtmKp78GekQ%40mail.gmail.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/1d59be9a-50d3-4fa4-b783-f349b6be7d1dn%40googlegroups.com >> >> <https://groups.google.com/d/msgid/neonixie-l/1d59be9a-50d3-4fa4-b783-f349b6be7d1dn%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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