Slashdot Mirror


Build A Nixie Tube Clock

J Aldridge writes: "People are still using Nixie tubes. Their warm glow seems to be the digital equivalent of the warm sound of vacuum amplifiers. One person has constructed a tube wristwatch."

50 of 126 comments (clear)

  1. hey by Joe+the+Lesser · · Score: 2, Funny

    Tube clocks? Weren't those out of style in the 80's?

    --
    "I only speak the truth"
    Karma: null(Mostly affected by an unassigned variable)
  2. Beware of following the instructions on this page by Harumuka · · Score: 4, Informative
    I, too, was tempted to buy a few Nixies to revive my cold and dank cellar, but stopped dead in my tracks soon as I saw a notice at the respectable RepairFAQ:
    This circuit was not isolated from the power line and has been removed due to the danger involved in such a setup.

    Although web archive's archives of the Repair FAQ only go back to 15 Feb 2K1, if I remember correctly the removed link went to the page Slashdot is linking too. Word from the wise: I'm not saying Nixies are inheirently dangerous, but many schmatics involving Nixie tubes do not isolate from the power line. And don't forget the big red warning on the page:

    Warning! As this design uses a transformerless power supply, the whole circuit is at mains potential. Disconnect before making any adjustments etc. If you need to use an oscilloscope for debugging, the circuit MUST be operated through an isolating transformer.
    --
    What do you think of MusicCity now?
  3. Re:Mmmm by digitalunity · · Score: 3, Insightful

    sounds dangerous!

    When can I have one?

    --
    You can't legislate goodness. Let each to his own destiny, by will of his freely made choices.
  4. cool clocks by Pathwalker · · Score: 5, Interesting

    The coolest looking nixie tube based clocks I've seen on the web are these over at World Power Systems.
    (Be sure to check out the Story Teller if you go to that site - extremely cool!)

  5. Reminiscent.. by Xerithane · · Score: 3, Interesting

    I used to date a girl whose fathers father worked for some government contract oufit (can't remember off the top of my head). He was part of the program to build the first digital clock. So, his team managed to do it and for about $60K in parts they built a clock that was slightly smaller than your desktop computers and used the nixie tubes for the display. This was by far the coolest clock I have ever seen, and probably ever will see. The girls dad ended up giving me the clock because of my fascination (and even he wasnt supposed to have it, funny story behind that for a later date) and the girl took it when we split up. One of those things I will never get over, but these clocks are so incredibly cool. I'm definitely not a compotent electrical engineer type person but would definitely consider buying one if anyone is in the building market.

    --
    Dacels Jewelers can't be trusted.
  6. Great! by Restil · · Score: 2

    Another geek project I'll have to add to the list of things I HAVE to do to feel complete. *sigh*

    Damn you slashdot! :)

    -Restil

    --
    Play with my webcams and lights here
  7. Warning from site by bryan1945 · · Score: 2, Interesting

    "Warning! As this design uses a transformerless power supply, the whole circuit is at mains potential. Disconnect before making any adjustments etc.
    If you need to use an oscilloscope for debugging, the circuit MUST be operated through an isolating transformer."

    As cool as this looks (yet still too much for me to tinker with), just this warning would put me off. One small error at 340V could be an, ahh, inconvience! And I didn't see any mention of what type of currents are running. Crispy!

    But seriously, having the rough equivalent of neon tubes for "UK£10/US$15 (excluding nixies)" would be neat. But considering that my lab group for EE201 blew out every circuit/component we tried to build in lab, I wouldn't trust myself with a soldering iron on anything more dangerous than an unplugged PCB board.

    --
    Vote monkeys into Congress. They are cheaper and more trustworthy.
    1. Re:Warning from site by Waffle+Iron · · Score: 2
      "Warning! As this design uses a transformerless power supply, the whole circuit is at mains potential. Disconnect before making any adjustments etc. If you need to use an oscilloscope for debugging, the circuit MUST be operated through an isolating transformer."

      This reminds me of a Heathkit oscilliscope kit I put together 20 years ago. The beam intensity control circuit used a normal TTL gate chip that was attached to the back of the tube. The chip's power and ground were connected between -2000 and -2005 volts(!).

      It the input signal to the chip (which was always pulsing to cancel DC potential) was controlled by the rest of the circuitry at between 0 and 5 volts, and this was transferred to the control chip via a huge high-voltage rated capacitor with 2000 volts accross it, which would wiggle the other end between -2000 and -2005 volts. An impressive hardware hack.

      As it happened, when I finished the scope and fired it up, it didn't work. It was pretty hard to debug without an oscilliscope :-/, and I was afraid of shocking the crap out of myself poking around 2000V circuits. I eventually got it working. It still works to this day, but the lame 5MHz bandwidth isn't too impressive.

  8. Darn it. by AtariDatacenter · · Score: 2

    I was clued into this here recently at another website. Now, with all the other geeks exposed to Nixie tubes, it looks like my chances of getting something, at least on eBay, are far worse. Nixie clocks (or, really, the tubes) are so cool because they're so retro. The displays are incredible.

    Another new hobbie vanquished by the Slashdot Effect.

  9. Coincidence. by Stillman · · Score: 2, Interesting

    Isn't life odd?
    Of all the obscure things to hit me twice in one day!

    A friend of mine has a page up detailing exactly this.

    He's a valve lover, not a web designer, but he has lots of pictures, and would love feedback! :)

    His main page is here.

    --
    Prisoner #655321
  10. Re:Mmmm by Shanep · · Score: 3, Interesting

    Does Vacume Fluro Display constitute Nixie?

    I have a Casio Mini (Casio's first handheld electronic calculator) that has 6 x 7 segment VFD displays. The tubes are seperate, perfect for H:M:S.

    This calc is interesting as it has a fixed decimal point not shown on the display and is not capable of user entry of a decimal point.

    Good condition with a slight dent and little corrosion on battery terminals. It's up for sale if anyone is interested in it or it's small tubes? Collectors item and I'm not a collector of old calcs (I prefer my 48GX).

    shanep AT ign DOT com DOT au

    --
    War crimes, torture, lies, illegal spying... Would someone give Bush a blowjob, already, so he can be impeached?
  11. Warm Memories by Doomsdaisy · · Score: 2, Insightful

    My uncle was a classic tech scrounger, and had all manner of things that used tubes and early transistors. I fondly remember when he once showed me one of his prized posessions, a nixie tube calculator. It was maybe 25x25cm and the warm glow of the numbers was much friendlier than the simple black on grey of the LCDs I grew up with.

    I could tell that even then it was something special by the way he treated it and obviously treasured it. It wasn't until I was older that I learned to appreciate the tech of yesteryear and the creativity and genius of those who created so much with the limited tools they had at the time.

    --
    These are breasts; this is source code.
    Why do you have a problem with those two things belonging to one person?
  12. 190 volts at... by Futurepower(tm) · · Score: 3, Informative


    I seem to remember: 190 volts minimum at 3 to 5 milliamps. Discouraging if you want to use batteries.

    Liquid Crystal Displays: A few volts at almost zero milliamps. If you had designed with Nixies, the discovery of LCDs was like God was giving us a gift.

    --
    Bush's education improvements were
    1. Re:190 volts at... by seanadams.com · · Score: 5, Informative

      I seem to remember: 190 volts minimum at 3 to 5 milliamps. Discouraging if you want to use batteries.

      Big whoop. It's not hard to make a switching power supply that will give you whatever voltage you want from a battery supply. Lots of sample circuits are out there.

      You can also buy inexpensive inverter modules that make 100VAC from a battery supply - typically used for powering LCD electroluminescent backlights. Seach on digikey for "backlight inverter".

  13. Forgot one thing... by Pathwalker · · Score: 3, Informative

    I hit submit rather than preview and neglected to add this:
    There is a good background writeup on nixie tubes here on part of the WPS site.

    Please don't bother moderating this up - it's at a high enough level that people will see it, and I've been at the cap for quite a while.
    (now, if someone were to flip my rtbl flag I'd be thankful...

  14. Gee, sounds about as useful as a... by khaladan · · Score: 3, Funny

    ...computer made out of vacuum tubes.

    Oh wait, that did end up being kind of useful :)

    Hurray for old tube things.

  15. Anyone actually selling nixie clocks? by NineNine · · Score: 2, Informative

    I would love to buy a nixie clock (I don't have the technical aptitude to build one), but I can't seem to find anyone who sells decent assembled, completed nixie clocks. Anyone know where I could get one? I have money to spend!

  16. Still have some ofthose tubes... by ackthpt · · Score: 2, Insightful
    In my dad's basement I have an old calculator with about 11 of those tiny nixies. Something to remember next time I fly back for a visit.

    Projects already on the back burner:

    Dynakit STA-35 amp

    Pioneer vacuum tube receiver (needs some small caps replaced)

    Still enjoy my old Ampeg V7 tube amp, too. Digital circuits seem to take extreme proportions to replicate the functions of the simplest old analog circuits. Not alway for the better, either.

    --

    A feeling of having made the same mistake before: Deja Foobar
  17. Even Cooler... by kzinti · · Score: 5, Interesting

    Wow, those nixie clocks bring back some fond memories. I always wanted to build a nixie project, but as a novice hardware hacker, couldn't even read the hookup schematic. Now, a little older, wiser, and with the help of these kits maybe I'll finally build one.

    However, while browsing some of the associated links, I came across this clock, which I find even cooler:

    http://www.cathodecorner.com/

    It uses an oscilloscope tube to draw the time in green phosphor arcs - no pixels. Way cool! And a kit is available with a guts-on-display plexiglass case. Awesome...

    --Jim

    1. Re:Even Cooler... by seanadams.com · · Score: 4, Interesting

      It uses an oscilloscope tube to draw the time in green phosphor arcs - no pixels.

      Very nice!

      If you don't feel like figuring out how to drive a CRT directly, there are some interesting things you can do with just a regular oscilloscope set to XY mode. Next time you're at Fry's, go to the aisle where they have all the oscilloscopes and function generators. This works best on a CRT scope, not a digital sampling scope. Hook two function generators to the scope inputs and set it to XY mode. Set the function generators to a sine wave, and play with the frequencies. You can generate all sorts of interesting lissajous figures.

      I once made a project using a PIC, a couple of DACs, and two stepper motors. The stepper motors were wired up like a "poor man's galvanometer" - the were driven by the DACs to move back and forth within a step. By mounting the motors at 90 degrees and hitting them with a laser pointer, I was able to make a pretty groovy portable laser show for about $40 worth of components.

      Another thing you can do if you don't feel like making your own hardware is to hook your sound card's left and right outputs to an oscilloscope. The you could write some simple software to draw these kinds of figures on the scope by just sending the wave forms out of your sound card. Unfortunately the frequency response is limited to the audible range so this is not ideal. A simple resistor-ladder DAC on the parallel port might work better because you could have <20HZ frequencies.

      It's amazing what you can do with a little geometry....

    2. Re:Even Cooler... by kzinti · · Score: 2

      Another thing you can do if you don't feel like making your own hardware is to hook your sound card's left and right outputs to an oscilloscope.

      You don't even need a scope to do this kind of thing. When I was 16 or 17, I learned how to disconnect the yoke from a TV and connect the inputs to other sources - a poor man's X/Y scope. One time a friend and I connected the horizontal and vertical yokes to the left and right outputs of his stereo's B speaker channel and made all sorts of cool patterns while we played Aerosmith until our ears bled. There must have been some horrible kind of impedance mismatch, though, because after a couple of hours, we completely burnt out his expensive high-power amp. Oops.

      Another time, while my girlfriend's parents were in Europe, we reversed the connection to their TV's vertical yoke coil to turn the picture upside down. We were going to leave it that way for her parents to discover, and thought they would find that hysterically funny. But when we realized they probably wouldn't figure out how to fix it, and that they'd probably spend a bunch of money on a TV repairman, we chickened out and put the picture back right-side up. Instead we turned upside down the abstract metal sculpture that hung above their fireplace.

      --Jim

    3. Re:Even Cooler... by kzinti · · Score: 2

      It had a single row of LEDs, mounted along a pendulum. The pendulum would swing back and forth, and the LEDs would flash so as to make it look like the current time was 'hanging' in the air in front of you.

      An electronics store here has this kind of clock, except the "pendulum" is inverted and motor driven. It scans back and forth very fast, and the red LED characters really seem to be hanging in midair. It's programmable and can be made to display the time and a short custom message. Pretty cool for $99 or thereabouts. I'm pretty sure Slashdot has covered this kind of gadget in the past.

      --Jim

    4. Re:Even Cooler... by jcapell · · Score: 2, Interesting

      made all sorts of cool patterns while we played Aerosmith until our ears bled

      One of my most prized posessions in college was an old B&W TV with 8 ohm vertical and horizontal coils.

      By FAR the coolest patterns were produced by Dire Straits from the Brothers in Arms LP - especially the song Telegraph Road. I still think it was all the pot smoke that eventually burned out my stereo, not the boob tube.

      At some point, I could actually look at the boob tube's patterns and identify what song was playing - I shite thee not!

  18. Re:Beware of following the instructions on this pa by zeet · · Score: 2, Interesting

    Oh, sheesh ... a minute and a half with Google turned up the following if you really want to see the circuit.

    http://margo.student.utwente.nl/el/misc/text_cir/f _asci2.htm

    Warning, this circuit Really Is Dangerous.

  19. Woohoo! by trivialproductions · · Score: 3, Funny

    I can now finish my Goldfinger-style atom bomb!

  20. Try Jaycar Electronics if you're in Australia ... by myelin42 · · Score: 2, Informative
    Jaycar Electronics in Australia stocks some vacuum fluorescent displays, kind of like mini-Nixies.

    If you're lucky, this link will take you to the description (and might even give you my session cookie :), otherwise go to the Online Catalogue page and select '-LEDs/Displays' from the dropdown menu then 'Search'.

    The one you're after is '11 Digit Fluoro Bargain'. Here are the details:

    Vacuum fluorescent displays - still look the best. Once again Jaycar has purchased a substantial quantity of a quality Futaba brand vacuum fluorescent displays. Each digit measures 6.0mm(H) x 3.5mm(W), 11 digits in all. The display also features an apostrophe in the top right hand corner of the digits, and a semicolon (;) in the bottom in all 11 digits. Electrical and mechanical data is incl in the price.
    Only A$1.70 each - about US$1.20 or so. I got two of them a couple of years back. Needless to say, they're still sitting in the cupboard, waiting for me to get around to making something with them ...
  21. Pinball Machines by ScottBob · · Score: 2

    Back in the late 70's - early 80's a number of pinball manufacturers used neon displays for the score, but they were flat and rectangular like vacuum fluorescents. Has anybody ever seen one with nixie tubes? That would look so cool.

    1. Re:Pinball Machines by KC7GR · · Score: 2, Interesting

      I've seen the odd Bally machine that used the neon displays for scoring. Said displays are called 'PanaPlex,' and they were originally developed by Burroughs Corp.

      They're kind of interesting in that they're nothing more than complex neon lamps. They consist of metal segments, laid out in the pattern of a seven or fifteen-segment display, sealed in a glass enclosure that contains (of course) neon. Apply about +130VDC to the common anode, and then ground the appropriate lead for the segment that you want to light up.

      I don't see them much any more, at least not in pinball machines. The reason, I think, is that PanaPlex displays did not stand up to vibration and shock particularly well, and pinball machines dispense both in generous quantity.

      For trivia buffs: There was one other type of vacuum display tube made that consisted of individual incandescent filaments, in the familiar seven-segment pattern, sealed into what looked for all the world like a standard miniature tube envelope. I don't recall who made them, but their trade name was 'Numitron.'

      Anyone remember any more about them? The BART system in the Bay Area (California) had loads of them in their old ticket machines and other digital readouts, such as those used on the station agent consoles.

      --

      Bruce Lane, KC7GR,

      Blue Feather Technologies

    2. Re:Pinball Machines by ScottBob · · Score: 2

      The display operated by mechanically moving strips of black plastic or mylar in front of an incandescent lamp, the digit to be displayed was a translucent portion of the mylar. These displays were once widely used in government and military applications, and into the mid '80s were used in the video switching systems of the CBS-TV network.

      You mean like the last of the old TV sets with knobs that you turn to change the channel? Rather than having the numbers on the knobs, there was a wheel with the numbers on it, and the channel you were on showed in a small window, illuminated from behind by an incandescent light. Now that I think of it, that might have been my first ever electronic personalization (analogous to a case mod), when the incandescent lamp went out, I found a green neon lamp to install in its place.

  22. Design considerations by insane · · Score: 2, Interesting

    I don't mean to be nit picky, but I question the qualifications of the person who designed that circuit. First off, there is no reason not to isolate the power supply from the main line. It doesn't add much cost, and the safety is well worth it. Especially on home built projects, it's already easy enough to shock yourself or start a fire (don't ask...I have done either too many times...) Second, there is also no reason to use the frequency of the mains to drive the circuit. Any one who has ever looked into that has noticed that the mains frequency varies quite a lot over time. Isolating the circuit and using an updated digital circuit or even a small micro-controller (PIC or 8x51) you could build a better, more accurate clock with more features for cheaper. I might even design one myself, put my EE degree to use...

    1. Re:Design considerations by Detritus · · Score: 5, Interesting

      While I agree with you about the need for a transformer for safety reasons, the mains frequency is useful for a clock. I built a Heathkit digital clock, back when digital clocks were rare items, that used the mains frequency as the input to the logic circuits. It never drifted more than a few seconds from the time signals broadcast by WWV. The power grid operators would adjust the frequency of the grid to keep the long term average frequency at exactly 60 Hz. If the frequency dropped during the day, due to high load, they would run it a bit fast at night to compensate.

      --
      Mea navis aericumbens anguillis abundat
    2. Re:Design considerations by ChadN · · Score: 2

      Since an isolating transformer was mentioned numerous times, I have to ask what exactly it gains you in terms of safety. Is it meant to step down the voltage of the mains to a much safer level? Or is it one-to-one, and if so, what is the "isolation" intended to do?

      Sorry, I'm a software guy...

      --
      "It's overkill, of course. But you can never have too much overkill." - Anonymous Slashdot Coward
  23. Re:Beware of following the instructions on this pa by eclectro · · Score: 3, Insightful



    All TV sets and computer monitors are this way too.

    If you work with the stuff it's a good idea to have an isolation transformer around (I've misplaced mine) There is a lot of High Voltage stuff in electronics. Know what you are dealing with, take all the right precautions, and hold one hand behind your back.

    --
    Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
  24. nixies--where they came from by Anonymous Coward · · Score: 4, Interesting

    The idea dates from around 1915--there were several patents for similar
    cold-cathode gas display devices before WWII.
    National Union made such numeric displays around 1940,
    the GI series tubes used bent wires to form numerals and
    had large 9-pin bases.

    The Haydu Brothers Co. developed what we call Nixies today
    circa 1947/48--
    Burroughs bought the Haydus out in 1952, making all their
    display tubes (and their complex "Trochotron" counter tubes)
    into Burroughs products. After Burroughs
    was absorbed by Unisys, tube manufacture ceased--however,
    companies such as Richardson/National and Philips were making
    Nixies well into the 1980s. Richardson still has the special
    tooling to make them, and could make more if demand
    appears. Prices for NOS Nixies are rising, because so many people
    are building clocks and fooling with old test equipment....

    --Eric Barbour
    VACUUM TUBE VALLEY magazine
    (www.vacuumtube.com)

  25. Re:And pissing into by Detritus · · Score: 2
    Where do you want your body sent?

    There is a big difference between a switching power supply designed by real engineers, with UL/CSA/TUV review and approval, and some random electronics project. Isolation transformers are a must for any electronic device that someone is going to poke around in with their bare hands.

    --
    Mea navis aericumbens anguillis abundat
  26. Re:Beware of following the instructions on this pa by driftingwalrus · · Score: 2, Informative

    And wear rubber-soled shoes.

    (NOTE: Holding one hand behind one's back and wearing rubber-soled shoes is to prevent the current from getting a path across one's heart)

    --
    Paul Anderson
    "I drank WHAT?!" -- Socrates
  27. Re:And pissing into by Detritus · · Score: 2

    Those are safety certifications, not reliability or performance certifications.

    --
    Mea navis aericumbens anguillis abundat
  28. Frequency by ESD · · Score: 2, Interesting

    In Europe the frequency actually can not deviate too much from 50 Hz, because all generators are locked into this frequency (if the frequency of one generator would be different an enormous current would flow from the other plants into this generator and it would most probably blow up). This system is used to cover peak loads:

    When a large load is applied to the grid, the frequency drops slightly and all generators in Europe deliver extra power to compensate for this (i.e. keep the frequency at 50 Hz), this is called frequency compensation.
    If the load persists longer, the plant/country/company responsible for the load increases its power output (thereby raising its frequency) to make sure the cost of this load is directed to the proper plant (power compensation).
    Due to the inertia of the entire European powergrid most of these frequency changes are no more than microHertzes, even when applying loads of megawatts.

    Just putting my "Process control in high-power electrical systems" course to use, I'm not an enormous expert in this field, and this course was a few years ago (my field is optical communications)..

  29. TV and monitor power supplies by wowbagger · · Score: 5, Insightful

    Actually, all modern power supplies ARE isolated from the power line - that's the core of a switching power supply.

    First, the incoming AC is rectified to DC and filtered. This gives you 300VDC on about 10 to 1000 microfarads of capacitance - enough to kill you dead if it goes through your chest. That part of the circuit is directly connected to the power line.

    Then the DC is chopped by a transistor and fed into a transformer (this is the "switching" part of the power supply). This chopping is done at between 60 kHz and 1 MHz (depending upon the power supply). The other side of the transformer (the secondary) is completely isolated from the power line. This voltage is then rectified, filtered, and supplied to the rest of the device. The voltage is measured, and fed back to the switching controller, which drives the switching transistor through either an optocoupler or pulse transformer, closing the feedback loop and regulating the voltage.

    If you look at a modern switcher, you will usually see the "hot" side is completely isolated - even unto having sections of the PCB cut to prevent arc-over.

    So, the bulk of the power supply, and the rest of the chassis, are NOT electrically connected to the power line. In fact, less of the system is connected to the power line than in an old style line frequency tranformer design. (Now, there were some old designs that rectified the power line and used that directly. THOSE designs were "hot" chassis designs, and were widowmakers...)

    That said, you shouldn't go poking around inside a monitor or TV unless you know what you are doing. The anode voltage on the CRT is between 12kV and 25kV (although the source impedance is high enough that it won't kill you). However, the deflection circuits that sweep the electron beam across the CRT are at about 400V and have enough energy to knock you on your ass.

    I've worked on TVs, monitors, radio transmitters (including tube based 250 watt repeaters (3kV at .1 amp, never work alone, one hand in your back pocket)) I design these things for a living.

    1. Re:TV and monitor power supplies by wurp · · Score: 2

      I'm no electrician, but I do have a degree in physics...

      How can you chop DC at any frequency? DC current has no frequency. And transformers only work on alternating current; it just makes a big electromagnet if you run DC through a transformer (and no current comes out the other side, except when you first apply the DC then again when you turn it off).

      What am I missing here? Or is it the original post that's off?

    2. Re:TV and monitor power supplies by Alsee · · Score: 2

      How can you chop DC

      no current comes out the other side, except when you first apply the DC then again when you turn it off

      Right. Do this over and over, really fast :)

      -

      --
      - - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
    3. Re:TV and monitor power supplies by wurp · · Score: 2

      Yes, but doing it over and over really fast is called AC.

    4. Re:TV and monitor power supplies by Alsee · · Score: 2

      is called AC.

      No. AC is alternating current, -AC Volts to +AC Volts. That is not quite the same as pulsed DC current.

      Going back to your older post:

      How can you chop DC at any frequency? DC current has no frequency.

      Read "chop" as "cut off". You can cut off DC current and turn it back on a number of times per second. That is the frequency. You get (ideally) a square wave between 0 Volts and +DC Volts.

      transformers only work on alternating current

      Transformers work on any change in current.

      -

      --
      - - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
    5. Re:TV and monitor power supplies by wurp · · Score: 2

      Good points all. I had a different (and wrong ;) definition of alternating current, and used sloppy verbage talking about transformers.

      But my biggest stumbling block was not knowing what 'chopping' DC meant.

      Thanks!

  30. It can SOURCE that, but for how LONG? by Svartalf · · Score: 3, Informative

    Microamps versus milliamps (Which, by the way, that switching supply will consume a couple of milliamps as well- not to mention you just bulked up your device considerably...). If it takes 5 micrnoamps to operate something and another unit takes 5 milliamps the microampere consuming device will last much longer.

    I don't believe that he was saying that it was impossible or that someone didn't do it- it was just a godsend for the people having to develop devices with numeric displays to not have to mess with Nixies.

    --
    I am not merely a "consumer" or a "taxpayer". I am a Citizen of the State of Texas
  31. Two strange Nixie Tube Devices by petep · · Score: 2, Insightful

    Around 35 years ago, ur company used to build frequency counters using Nixie Tubes. One of our engineers got hold of some Nixie tubes that displayed dollar-signs. He built a device called "ExecuMeetingCounter". It had a couple digital thumbwheel switches labelled "attendees". You dialed in the number of people in the meeting and the device sat on the conference table and tallied up the cost of the meeting (using some arbitrary per-person cost).

    Another fellow employee built a Nixie tube clock, but it used a 3-foot long glass PENDULUM as the rate determining device. A photodetector sensed the passing of the pendulum, incrementing the clock counters and sending a pulse to a coil to give the pendulum a "kick" to keep it going. It was an amusing mixture of old and new (at that time) technology.

  32. Re:Beware of following the instructions on this pa by the_quark · · Score: 3, Insightful

    The rule I was taught was to consciously decide not only to put one hand behind your back, but to hold your belt. I was also encouraged to think about holding my belt, to avoid the unconscious, "I just need another hand on the other side of this" which ends up with one hand holding a negative terminal and the other a positive, and the current running straight across your heart.

    When I was 17 (before I'd been taught all that), I was helping a friend hook up an electric fence. The transformer had a wing nut on each side as a terminal, and was mounted to the wall by a nail at the top. For some IDIOTIC reason, I was trying to hook the fence up plugged in. Now, you often do have to work on live electrical equipment, but this was clearly not one of those cases.

    So, in any event, I hooked up one lead, and was tightning the wing nut for one lead. Of course, since the transformer was hung from a single point, it was flopping around. Without even thinking about it (a lot of not thinking going on, that day), I swung up my left hand to stabalize the transformer... And grabbed the oposite terminal.

    I remember standing there, with the muscles in my arms convulsing, and I thought, "I've got to do something." My chosen course of action was to yell "SHIIIIITTT!" at the top of my lungs. It didn't seem to improve my situation any, so I thought for a bit on what might be more productive. In one convulsive movement, I threw myself away from the transformer (my hands were locked to it by muscle spasms from the current).

    So, children, that is why you should grab your belt with one hand, and hang on for dear life.

  33. Display technologies, clocks, associated crapola by tomjennings · · Score: 4, Interesting

    Yes, technologically, Nixies & related are a pain to interface to +5V CMOS logic, but that's not the point. LCDs are clearly superior in sooo many ways, but they are... well, boring.

    Pretty much all instrumentation these days looks the same, membrane switch, LCDs, a few LEDs, a pile of nifty software, an order-of-magnitude more accurate than the previous model, runs on a AA cell for 2 years until you throw it out.

    However, our lovely bodies are physical, and they like being enticed with 'interface' (sic) that connects with more than just yore brane. You can *touch* nixies, the glass is nice to touch, and so are heavy bakelite knobs, switches you can *feel* change state.... Nixie digits jump around. The orange color works well with your eyes. There's no blinky multiplex updates to dazzle.

    In general, pre-photomicrolithography electronic stuff was more fun to touch and use (though largely sucked when it came to power consumption, reliability, size, heat output, portability, ad nauseum) as is quite obvious.

    A Tektronix scope is an excellent example of technology and interface design and of paradigms lost -- they use first-principle physics (the cathode ray tube is more than just a display, it's an integral measurement component), a mixture of solid-state and state-of-the-art electron tubes, analog computing components (verniers), big clicky knobs, coded by color, size, shape and placement, nice colors and shape, a manual that contains data and meta-data (operating, maintenance, design! and curious gratuitous cartoon graphic characters walking along signal paths...) Like other targetd instrumentation, it embodied and defined a culture of use that was far more ... fun.

    But performance-wise, my TDS-220 software'n'LCD 100MHz BW gigasample scope, the size of an old table radio, is incomparable. It's a pretty amazing contrast for only 30 years of development.

    But now we get the best of both worlds (sic), teensy micros under the nice part of the old stuff. I think it's a pretty normal development, culturally, this re-use of the "outsides" of old equipment to achieve a revisionist view.

    Interface is always where the interesting stuff is.

    The best nixie and 'scope clock technology out there today, is hands-down, David's (http://www.cathodecorner.com), surface mount, AC power line isolation, small, low-power, software driven, switcher HV supply, reasonable price (no I get no kickback frmo his sales).

    I wrote a brief history of nixie and decimal tube history here: http://wps.com/texts/decimal-tubes/index.html, nothing exhaustive, but a good start.

    For home-brew, a transformer/diode bridge/series regulator with zener is somewhat crude, but easy to make, reliable, and reasonably low power. For a transformer I use a Thordarson-Meissner # 26R60 transformer from Allied Electronics (web order) around $19 each (provides 6.3V and 150V outputs). This is no where near as elegant as David's but for one-off it's fine.

    I too make clocks (http://wps.com/products) but I'm not in the clock business per se, mine are simply art (more accurately craft) objects, though I'll make more. My emphasis is more on a functional, tactile artifact, a Nice Thing to hold and use. I've only made a half dozen so far, I've got another half-dozen in the works. After I use up my stock of PCBs I'll end up buying guts from David, it's a much better design.

  34. I purchased a Nixie Tube Multimeter last year... by SlashMaster · · Score: 2

    I found a nixie tube multimeter in a government surplus pallet that I purchased last year. I remembered the nixie tubes from a calculater in our math room from high school and also from some of the frequency counters we used in college.

    I took it out and plugged it in. It didn't work. I then got curious and took it apart to find a fuse blown. I replaced it and it lit up like a brand new multimeter.

    There is something about the 3-Dimensionality of it. The numbers that it comes up with literally jump out at you or jump away from you. It's soo cool...even if its got a beige plastic case.

    Unfortunately people at work didn't share my admiration for it(Something about being out of date). I had to take home here where it commands a distinguished place on my bookshelf.

  35. Re:Chopping DC by wurp · · Score: 2

    Ah, yup, this is exactly the info I was looking for. When he said chopping, I thought he was talking about low and high pass frequency filters, which didn't make sense for obvious reasons.

    Thanks much!