I've had 2 74141 chips fail on my Ramos prototype within the span of a couple of years. In each failure a digit would always stay on. I'm not sure if this was my fault, but I tried to take every precaution with my circuit design. I drove 4 in12's at 170v dc with 4 russian 74141 chips.
At this point, I don't want to use them anymore. I feel like there's not point in relying on old soviet ic's when you can use modern solid- state technology with a little extra effort. Granted, the 74141's are so damn easy and convenient to use. The HV5530 look awesome, especially with the built in shift registers. If I were making one- off's i'd just use those. But you can only drive 3 tubes with one chip, and with a 4 digit clock, the unused 2 channels are a waste, especially looking at the high cost of the chip (if you're mass producing clocks this is prohibitive). On the production Nixie Ramos clocks I intend to use these: http://www.nxp.com/documents/data_sheet/PMBTA42DS.pdf They are dual NPN 300v transistors that are really cheap. The downside is that there are only 2 transistors per chip, so that's 5 per digit, so they are going to significantly increase your part count on your board. But they seem ultra-reliable, and at the cost I think they justify the added part count. -Paul On Mar 1, 3:58 pm, Deviantgeek <d3viantg...@gmail.com> wrote: > I will be building 2 clocks in the near future, and putting board > space together and all, the HV5522 are better for me. They are the > same chip as the HV5530, and a little cheaper. From what I understand > from the datasheet, I can give them ~12v and 5v logic and they should > work fine. This seems to be how Jeff uses them in his clocks. > Thanks! > > On Mar 1, 10:37 am, "Tidak Ada" <offl...@zeelandnet.nl> wrote: > > > > > > > > > Me is said that the Russian K155XXx series has an aberrant (metric) pitch of > > 2,5mm instead of 0.1" (2,54mm) You have to consider that in your lay-out. > > > Btw., I have here a condensed pdf of the K155XXx series datasheets (not as > > extended as Western ones). > > > eric > > > -----Original Message----- > > From: neonixie-l@googlegroups.com [mailto:neonixie-l@googlegroups.com] On > > > Behalf Of Adam Jacobs > > Sent: donderdag 1 maart 2012 16:06 > > To: neonixie-l@googlegroups.com > > Subject: Re: [neonixie-l] Re: Alternative to MPSA42 for direct drive clocks. > > > The 74141 or K155ID1 will both work fine for cathode side blanking, provided > > that your HV supply is a normal value (180vdc). If you are using something > > very high, like 250v, then you're going to start running into the problem > > that the 74141/K155ID1 are not able to extinguish the nixie. FYI, the > > K155ID1 has somewhat different voltage characteristics than the 74141. I > > understand that the 74141 can sink something like 60v, where the K155ID1 can > > sink 100v. > > I think that most nixies extinguish at about 135vdc or so. > > > -Adam > > > On 3/1/2012 6:52 AM, Ron Schuster wrote: > > > Could you clarify something for me? Are you saying is that a 74141 > > > should not be used for cathode-side blanking? What about the Russian > > > K155ID1, which I assume has similar specs to the 74141? > > > > On Feb 28, 7:24 pm, David Forbes<dfor...@dakotacom.net> wrote: > > >> On 2/28/12 4:48 PM, Deviantgeek wrote: > > > >>> I was looking at the Supertex drivers, mainly the HV5522. Its 220v vs > > >>> 300v, would that still work? I am driving 6 IN-18 tubes. I was also > > >>> looking at the SN75468, and a few 50v drivers(TPIC6A596)which I think > > >>> is too low... I will be building several clocks, and I want good, > > >>> reliable, cheap drivers. > > >>> (this is just for the cathodes) > > >> The voltage required depends on what sort of control you plan to use, > > >> and how many volts you apply to the anodes. The important thing to > > >> remember is that if one cathode is lit, then the other cathodes don't > > >> need more than 50V to turn them off. That's why the 74141 works with its > > >> 55V Zener diode clamps on its outputs. > > > >> If you want to display one or two cathodes in every tube at all times > > >> (no blanking, but possibly fading between numbers), then a 50V driver is > > >> barely sufficient. Or you can use an anode driver to blank the tube. I > > >> use the TD62083 in my Nixie watch, and it works fine. > > > >> If you want to blank the digit with the cathode, then a 100V driver > > >> would be necessary and you'd need to use a power supply below 200V. > > > >> If you want to blank the tube and use a>200V supply, then you need a > > >> higher voltage cathode driver or an anode blanking circuit. > > > >> I think most of the Supertex parts want 12V on their signal lines, so > > >> they are not very easy to use since normal logic uses 5V levels. > > > >> -- > > >> David Forbes, Tucson AZ > > > -- > > You received this message because you are subscribed to the Google Groups > > "neonixie-l" group. > > To post to this group, send an email to neonixie-l@googlegroups.com. > > To unsubscribe from this group, send email to > > neonixie-l+unsubscr...@googlegroups.com. > > For more options, visit this group > > athttp://groups.google.com/group/neonixie-l?hl=en-GB. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. 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