[neonixie-l] Re: Constant current source design
> > Yes, I agree with Tomasz, the first circuit shown in the article he links > to is the way to do it. Advantages: No "wasted" current draw, cheap and > easy. Ignore the comments in that article about the problems of voltage > drop - that might be important when you've only got 5V to play with, but > with 200V on tap... !! > Suggest RSense of 120 Ohms should regulate the current to 5mA, then make R1 anywhere between 100K and 220K. Not critical. Use a high voltage MPSA42 transistor or similar for T1, T2 can be any old jelly bean type. While this constant current source will be inherrently short-circuit proof (the most current that will ever flow will be 5mA), be aware that under those conditions a humble MPSA42 will be dropping 1 Watt and will fry pretty quickly! Something a little beefier in the power stakes might then be a better choise. -- 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+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/a9018ffa-cc32-439e-8a11-5d7a549310c7%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [neonixie-l] NOT another nixie clock!
Thansk for your thoughts, Greg. The final choice of processor is probably going to be influnced more by software development (and learning curve) that the hardware costs, given that I doubt I'll make even 50 of the finished NDMM (as it will henceforth be known). I can crash about a bit in Python, but the interpretted nature of that language gives me concerns over speed. The boot-time and seemingly easy ability to "trash the SD card" are worries for me in an embedded product. I know nothing of FPGAs, so the learning curve for me could easily be the most "expensive" part (even if it was the neatest solution). Arduinos are everywhare, and I can probably leverage some of my experience with PIC processors (some C, but mostly assembler) in that direction. Dont actually need that much IO, just 3-4 serial channels and a few spare lines for keyboar scanning. What do the group make of TEENSY processors? Laurence On Saturday, 8 October 2016 20:17:22 UTC+1, gregebert wrote: > > It's a classic tradeoff regarding RasPi vs Arduino vs FPGA. Everyone has > different pain-points for cost, power, boot-time, features, development > effort, etc. > > Maybe Aduino is a better option; I'm going that route for my next clock > project. If you plan your design, you can add various shields for added > features and still run the DMM and nixies (maybe thru I2C ?). My only > dislike regarding Arduino is the I/O is rather slow, and there aren't a lot > of pins. > > An FPGA will give you the fastest boot-time (milliseconds), tons of I/Os, > and probably lowest power-consumption (below 400mW for me), but it involves > the most work (you better be a good Verilog or VHDL coder). I've done 3 > different clock designs with FPGA's, and it was a bit more work developing > the code. However, it's far, FAR better than hardwired logic such as what I > did on my first nixie clock. > > A RasPi will have everything you want, plus more. But it's going to cost a > bit more and use more power. However, it makes code updates very simple > (connect to internet & download), not to mention you can do bizarre things > like logging into your device even if it's at a customer site far, far > away. > > I do have the option of pulling the FPGA or Arduino aside and using > something else such as a RasPi, if I wish, on most of my designs (OK, not > the wristwatch...). > > > > -- 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+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/978c3d84-9104-42e8-b5f8-801ca9a50704%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [neonixie-l] NOT another nixie clock!
Thanks for your interest, I'll keep you posted! On Friday, 7 October 2016 20:44:53 UTC+1, Nortonian wrote: > > Greetings Nixiers, > > Laurence, i think it's a fabulous idea. I, too, have been thinking about > non-clock nixie projects, but hadn't thought of a modern bench meter. > Great idea! To those like Dylan (and me) who are a little nervous about > the pricing, i suggest starting a NMM fund *now*. Less than $50 a month, > and when it's ready, you'll be able to put cash on the barrelhead! > > In all seriousness, Laurence, i hope you go forward with this project, > and count me in for a kit. > > All the best, > Sam > > > On 2016-10-07 15:07, Dylan Distasio wrote: > > I would love one, and applaud the idea, but that price point will put > > it out of range for me. > > > > On Oct 7, 2016 3:02 PM, "Laurence Wilkins" > > wrote: > > > >> Over almost the last ten years, I have been designing, producing and > >> selling a variety of logic and PIC Micro-controlled nixie clocks, > >> from classic 2x3 mux 74141-based designs to multiplexed and direct > >> drive IN18 monsters, to miniature desk clocks and single digit > >> weirdness. I feel I've "been there" now, and want to find other > >> appropriate outlets for these glorious glowing anachronisms! (that > >> is: nixie tubes). > >> > >> I've been giving some serious thought recently to designing and > >> building a good quality 50,000 count (4 3/4 digit) Bench Digital > >> Multimeter with a fair few (sensible) bells and whistles, but of > >> course with a nixie display. It would use a standard but very > >> capable DMM "front-end" chip to do all the measurement, > >> opto-isolated to a controller and then onto a direct drive nixie > >> display (with Volts/Amps/Ohms/Hertz symbols!) Battery or mains, USB > >> output (or is that input?). I am aiming for CAT IV performance by > >> design (but not by certification - too expensive), good accuracy as > >> afforded by the front end chip, and in a good quality case (likely > >> to be the most expensive component). I'd like to offer it both as an > >> assemble-able kit (so I'd presolder small SMD parts) or a fully > >> assembled instrument. This would be a "serious" bit of kit, not > >> something which _looks like_ it was thrown together in a biscuit > >> tin! I've yet to decide whether the software would be open source, > >> but it might be nice to let "the community" develop additional > >> functions in software (data logging, averaging, etc.) > >> > >> I aim to produce a batch of maybe 50 instruments, but I really > >> don't have much of a clue as to the demand, out there. "It's going > >> to depend on cost," you say. Well, based on BOM costs so far, it is > >> not going to come in much (if anything) below about GBP £400 (USD > >> $550). Yes, you could spend that on a new meter and get guaranteed > >> similar specs, but _it wouldn't have a nixie display_ which is of > >> course the unique selling point. > >> > >> It might take me around 12 months from pressing the button to a > >> finished product. I've looked, but there appears to be nothing else > >> out there. > >> > >> So what does the group think? Are we nixie nuts a very small group? > >> Are clocks enough? Is that price way too high? (the BOM costs means > >> the price can’t be much lower, for small volumes!) > >> > >> Regards > >> > >> Laurence > >> > >> www.MrNixie.com [1] > >> > >> (the one in England they call) Mr Nixie > >> > >> -- > >> 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 post to this group, send email to neoni...@googlegroups.com > . > >> To view this discussion on the web, visit > >> > > > https://groups.google.com/d/msgid/neonixie-l/6f8b3456-3add-41b2-9106-765741d98a48%40googlegroups.com > > >> [2]. > >> For more options, visit https://groups.google.com/d/optout [3]. > > > > -- > > You received this message because you are subscribed to the Google > > Groups "neonixie-l&qu
Re: [neonixie-l] NOT another nixie clock!
Yes, my envisioned Nixie DMM will include a frequency counter, but not fancy period or averaging functions, not much beyond maybe 40MHz. On Saturday, 8 October 2016 16:11:05 UTC+1, Jonathan wrote: > > I too have as many clocks as I need, although I haven't made as many as > you. I have a kitchen timer, an indoor outdoor thermometer (pixies) and a > hot tub temp. display. I have an HP VOM that I have been meaning to fix. > > I have been planning to make a frequency counter. In my case I would use > it as part of a custom ham radio, nixies for frequency, neon bar graph tube > for an S meter, magic eyes for forward and reflected power, that sort of > thing. Others might use it for all sorts of purposes, like measuring RPM. > > $500 is way beyond what I can spend on a meter. :-( > > Jonathan > > > > I've been giving some serious thought recently to designing and building a > good quality 50,000 count (4 3/4 digit) Bench Digital Multimeter with a > fair few (sensible) bells and whistles, but of course with a nixie display. > It would use a standard but very capable DMM "front-end" chip to do all the > measurement, opto-isolated to a controller and then onto a direct drive > nixie display (with Volts/Amps/Ohms/Hertz symbols!) Battery or mains, USB > output (or is that input?). I am aiming for CAT IV performance by design > (but not by certification - too expensive), good accuracy as afforded by > the front end chip, and in a good quality case (likely to be the most > expensive component). I'd like to offer it both as an assemble-able kit (so > I'd presolder small SMD parts) or a fully assembled instrument. This would > be a "serious" bit of kit, not something which *looks like* it was thrown > together in a biscuit tin! I've yet to decide whether the software would > be open source, but it might be nice to let "the community" develop > additional functions in software (data logging, averaging, etc.) > > > I aim to produce a batch of maybe 50 instruments, but I really don't have > much of a clue as to the demand, out there. "It's going to depend on cost," > you say. Well, based on BOM costs so far, it is not going to come in much > (if anything) below about GBP £400 (USD $550). Yes, you could spend that on > a new meter and get guaranteed similar specs, but *it wouldn't have a > nixie display* which is of course the unique selling point. > > > It might take me around 12 months from pressing the button to a finished > product. I've looked, but there appears to be nothing else out there. > > > So what does the group think? Are we nixie nuts a very small group? Are > clocks enough? Is that price way too high? (the BOM costs means the price > can’t be much lower, for small volumes!) > > > -- 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+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/477ef3a9-c91e-4665-a8a4-859118f25b7c%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [neonixie-l] NOT another nixie clock!
Thanks for your note. Well, you can buy "front end" DMM chips that just do the measuring with no built in display, but some serial I/O to a processor/display/keyboard combo. That's my route. Not settled on the processor, yet. I also play with Raspberry Pis, and while I might use one for early software development, I have ruled them out for a place in the final product for a couple of reasons. The most annoying aspect of my otherwise nice Fluke 289 DMM is the ~10 second boot time. I want that voltage reading, NOW! Pi's boot in around 30 seconds, and even though the application is for a bench meter, I would find that start-up delay frustrating. Also, as others have found, Pi's do not take kindly to just being switched off, without a proper power-down. I need something more reliable and able to withstand "mild" abuse that that. On Friday, 7 October 2016 20:56:45 UTC+1, gregebert wrote: > > Yeah, that's a project I've thought about, but my conclusion was that the > DMM chips were all intended for direct-drive LCD, or perhaps LED. I get > stuck in an endless loop of trying to justify building something really > interesting that wont get used very much vs adding features that would be > unique (measure milliohms, inductance, kilovolts, and true-RMS milliwatts). > Guess what...I get nowhere. > > A Raspberry Pi would likely be the best platform, as there is all sorts of > software out there to enable it to run as a networked device. > -- 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+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/7bee337a-b53b-48f5-88d9-2267eb9127eb%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [neonixie-l] NOT another nixie clock!
Thaks for your reply, William. Yeah, well, it costs a lot (before I consider any return for my time!). This is my concern - if the market fo rthe price I need to charge isn't there, I don't have a project, after all... On Friday, 7 October 2016 20:07:56 UTC+1, William Lee wrote: > > I would love one, and applaud the idea, but that price point will put it > out of range for me. > > On Oct 7, 2016 3:02 PM, "Laurence Wilkins" > > wrote: > >> Over almost the last ten years, I have been designing, producing and >> selling a variety of logic and PIC Micro-controlled nixie clocks, from >> classic 2x3 mux 74141-based designs to multiplexed and direct drive IN18 >> monsters, to miniature desk clocks and single digit weirdness. I feel I've >> "been there" now, and want to find other appropriate outlets for these >> glorious glowing anachronisms! (that is: nixie tubes). >> >> I've been giving some serious thought recently to designing and building >> a good quality 50,000 count (4 3/4 digit) Bench Digital Multimeter with a >> fair few (sensible) bells and whistles, but of course with a nixie display. >> It would use a standard but very capable DMM "front-end" chip to do all the >> measurement, opto-isolated to a controller and then onto a direct drive >> nixie display (with Volts/Amps/Ohms/Hertz symbols!) Battery or mains, USB >> output (or is that input?). I am aiming for CAT IV performance by design >> (but not by certification - too expensive), good accuracy as afforded by >> the front end chip, and in a good quality case (likely to be the most >> expensive component). I'd like to offer it both as an assemble-able kit (so >> I'd presolder small SMD parts) or a fully assembled instrument. This would >> be a "serious" bit of kit, not something which *looks like* it was >> thrown together in a biscuit tin! I've yet to decide whether the software >> would be open source, but it might be nice to let "the community" develop >> additional functions in software (data logging, averaging, etc.) >> >> I aim to produce a batch of maybe 50 instruments, but I really don't have >> much of a clue as to the demand, out there. "It's going to depend on cost," >> you say. Well, based on BOM costs so far, it is not going to come in much >> (if anything) below about GBP £400 (USD $550). Yes, you could spend that on >> a new meter and get guaranteed similar specs, but *it wouldn't have a >> nixie display* which is of course the unique selling point. >> >> >> It might take me around 12 months from pressing the button to a finished >> product. I've looked, but there appears to be nothing else out there. >> >> >> So what does the group think? Are we nixie nuts a very small group? Are >> clocks enough? Is that price way too high? (the BOM costs means the price >> can’t be much lower, for small volumes!) >> >> >> Regards >> >> >> Laurence >> >> www.MrNixie.com >> >> >> (the one in England they call) Mr Nixie >> >> -- >> 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 post to this group, send email to neoni...@googlegroups.com >> . >> To view this discussion on the web, visit >> https://groups.google.com/d/msgid/neonixie-l/6f8b3456-3add-41b2-9106-765741d98a48%40googlegroups.com >> >> <https://groups.google.com/d/msgid/neonixie-l/6f8b3456-3add-41b2-9106-765741d98a48%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > -- 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+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/432597c6-b77a-4af1-8aed-d81b7a45fd68%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[neonixie-l] NOT another nixie clock!
Over almost the last ten years, I have been designing, producing and selling a variety of logic and PIC Micro-controlled nixie clocks, from classic 2x3 mux 74141-based designs to multiplexed and direct drive IN18 monsters, to miniature desk clocks and single digit weirdness. I feel I've "been there" now, and want to find other appropriate outlets for these glorious glowing anachronisms! (that is: nixie tubes). I've been giving some serious thought recently to designing and building a good quality 50,000 count (4 3/4 digit) Bench Digital Multimeter with a fair few (sensible) bells and whistles, but of course with a nixie display. It would use a standard but very capable DMM "front-end" chip to do all the measurement, opto-isolated to a controller and then onto a direct drive nixie display (with Volts/Amps/Ohms/Hertz symbols!) Battery or mains, USB output (or is that input?). I am aiming for CAT IV performance by design (but not by certification - too expensive), good accuracy as afforded by the front end chip, and in a good quality case (likely to be the most expensive component). I'd like to offer it both as an assemble-able kit (so I'd presolder small SMD parts) or a fully assembled instrument. This would be a "serious" bit of kit, not something which *looks like* it was thrown together in a biscuit tin! I've yet to decide whether the software would be open source, but it might be nice to let "the community" develop additional functions in software (data logging, averaging, etc.) I aim to produce a batch of maybe 50 instruments, but I really don't have much of a clue as to the demand, out there. "It's going to depend on cost," you say. Well, based on BOM costs so far, it is not going to come in much (if anything) below about GBP £400 (USD $550). Yes, you could spend that on a new meter and get guaranteed similar specs, but *it wouldn't have a nixie display* which is of course the unique selling point. It might take me around 12 months from pressing the button to a finished product. I've looked, but there appears to be nothing else out there. So what does the group think? Are we nixie nuts a very small group? Are clocks enough? Is that price way too high? (the BOM costs means the price can’t be much lower, for small volumes!) Regards Laurence www.MrNixie.com (the one in England they call) Mr Nixie -- 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+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/6f8b3456-3add-41b2-9106-765741d98a48%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
