[Fran]’s LEDs, Nixies, and VFDs.


With a love of blinky and glowey things, [Fran] has collected a lot of electronic display devices over the years. Now she’s doing a few teardowns and tutorials on some of her (and our) favorite parts: LEDs and VFD and Nixie tubes

Perhaps it’s unsurprising that someone with hardware from a Saturn V flight computer also has a whole lot of vintage components, but we’re just surprised at how complete [Fran]’s collection is. She has one of the very first commercial LEDs ever made. It’s a very tiny red LED made by Monsanto (yes, that company) packaged in a very odd lead-and-cup package.

Also in her LED collection is a strange Western Electric part that’s green, but not the green you expect from an LED. This LED is more of an emerald color – not this color, but more like the green you get with a CMYK process. It would be really cool to see one of these put in a package with red, green, and blue LED, and could have some interesting applications considering the color space of an RGB LED.

Apart from her LEDs, [Fran] also has a huge collection of VFD and Nixie tubes. Despite the beliefs of eBay sellers, these two technologies are not the same: VFDs are true vacuum tubes with a phosphorescent coating and work something like a CRT turned inside out. Nixies, on the other hand, are filled with a gas (usually neon) that turns to plasma when current flows through one of the digits. [Fran] has a ton of VFDs and Nixies – mostly military surplus – and sent a few over to [Dave Jones] for him to fool around with.

It’s all very cool stuff and a great lead-in to what we hear [Fran] will be looking at next: electroluminescent displays found in the Apollo Guidance Computer.

Videos below.

Continue reading “[Fran]’s LEDs, Nixies, and VFDs.”

Once, Twice, Three Times a Nixie

Try as he might, [Localroger] can’t seem to throw away a certain board that started life in one of the first digital industrial scales, the NCI DigiFlex model 5775. He recently gave it a third career as a nixie clock with an alarm.

[Localroger] says the board dates to about 1975. It’s all TTL, no microprocessor anywhere. He was headed to the Dumpster with it in the mid-1980s, but realized that he could hack it into something useful. Since the display wasn’t multiplexed, it would be fairly easy. He used it as a BCD tester for about 10 years until the method fell out of fashion.

After a decade on the shelf, [Localroger] started off for the Dumpster once more with the board. The nixie tube display cried out for another chance to glow, so he decided to repurpose it into a remote-controlled bedside clock with an alarm. He installed a Parallax Propeller Protoboard with headers for easy removal and subsequent servicing of the 5775 board. He added a few things to the protoboard: a piezo element for the alarm, a SparkFun RTC module, an IR receiver, and vertically-oriented header so the PropPlug can be plugged in from the top. But that’s not all. [Localroger] designed a custom melamine-finished MDF enclosure and laser cut it, giving the edges a nice contrast. It’s so tough, he can put his ceramic lamp on top of it to save space on the nightstand.

Nixie tubes are becoming more scarce all the time. If you can’t find any, we humbly suggest rolling your own.

[Thanks Localroger!]

VFD And Nixie Clock Twofer


Sometimes the stars align and we get two somewhat similar builds hitting the Hackaday tip line at the same time. Recently, the build of note was clocks using some sort of display tube, so here we go.

First up is [Pyrofer]’s VFD network time clock (pic, above). The build started as a vacuum flourescent display tube he salvaged from an old fruit machine – whatever that is. The VFD was a 16 character, 14 segment display, all controlled via serial input.

The main control board is, of course, an Arduino with a WizNet 5100 Ethernet board. The clock connects to the Internet via DHCP so there’s no need to set an IP address. Once connected, the clock sets itself via network time and displays the current date, time, and temperature provided by a Dallas 1-wire temperature probe.

Next up is [Andrew]’s beautiful Nixie clock with enough LEDs to satiate the desires of even the most discerning technophile. The board is based on a PIC microcontroller with two switching power supplies – one for the 170VDC for the Nixies, and 5V for the rest of the board.

A battery backed DS1307 is the real-time clock for this board, and two MCP23017 I/O expanders are used to run the old-school Nixie drivers

All this is pretty standard for a Nixie clock build, if a little excessive. It wasn’t enough for [Andrew], though: he used the USB support on his PIC to throw a USB port on his board and wrote an awesome bit of software for his PC to set the time, upload new firmware, and set the color fade and speed. With this many LEDs, it’s not something you want in your bedroom with all the lights on full blast, so he implemented a ‘sleep’ mode to turn off most of the lights and all the Nixie tubes. It’s a great piece of work that could easily be successfully funded on Kickstarter.

Measuring The Lifespan Of Nixie Tubes


Nixie tubes have two things going for them: they’re awesome, and they’re out of production. If you’re building a clock – by far the most popular Nixie application, you’re probably wondering what the lifespan of these tubes are. Datasheets from the manufacturers sometimes claim a lifetime as low as 1000 hours, or a month and a half if you’re using a tube for a clock. Obviously some experimentation is in order to determine the true lifetime of these tubes.

Finding an empirical value for the lifetime of Nixies means setting up an experiment and waiting a very, very long time. Luckily, the folks over at SALTechips already have a year’s worth of data.

Their experimental setup consists of an IN-13 bargraph display driven with a constant current sink. The light given off by this Nixie goes to a precision photometer to log the visual output. Logging takes place once a week, and the experiment has been running for 57 weeks so far.

All the data from this experiment is available on the project page, along with a video stream of the time elapsed and current voltage. So far, there’s nothing to report yet, but we suppose that’s a good thing.

Homemade Nixie Tubes

Do you love Nixie Tubes? Upset that they aren’t really manufactured anymore, and the cost of old ones is rising? Why not make your own? That’s exactly what [Dalibor] of the Czech Republic is up to, including blowing the glass tubes himself!

He’s chosen the Z568 nixie tubes to copy, as they are his favorite style of nixie. To create the display he has etched the digits and housing out of 0.3mm stainless steel sheet — which potentially means if he gets the hang of making the tubes, he could actually produce them to sell! To perform the glass blowing, he scored a Heathway glassblowing lathe off eBay — but unfortunately he hasn’t documented much of anything on making the glass tubes, which is too bad because we think that would be equally fascinating as the nixie displays themselves. On his first attempt with a properly sealed tube, the nixie worked and he even recorded striking voltage values very similar to industry tubes — not bad for something made in a backyard shed!

He has since then continued refining this art and is entering a glass-art contest called “When Prague Meets Shanghai” with a beautiful entry dubbed the ShanghaiTime Nixie Clock.

If this post seems vaguely familiar, it’s because this isn’t the first time we’ve posted an article about homemade nixie tubes, but we think [Dalibor’s] is by far the most elegant! Stick around after the break to see one of his first test videos — You might even think he’s cheating, the tubes look so professional!

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A simple nixie clock with logic gates

Here is a very nice project that [Znaxque] finished a few months ago: a simple nixie clock made with logic gates only. In this build, the mains 50Hz is used as a time base instead of a 32KHz crystal that most readers here may use. In the very long term, this clock may actually be more precise than a crystal-based one as power companies in Europe adjust the mains frequency. However, at a given moment the difference between this clock and a reference may be as big as 60 seconds.

The design was sketched on a simple piece of paper and later made using salvaged ICs. [Znaxque] only bought the six IN-14 nixies for $45 and the veroboard shown in the picture above. The BCD to Decimal decoders are 74141s and three buttons are present on the board to set minutes, hours, as well as resetting all the counters.

NES: Nixie Entertainment System


[Bradley W. Lewis] is no stranger to Nixie clock builds, and he felt his latest commission was missing something. Instead of merely mounting the Nixie clock into a case resembling an NES console, he goes full tilt and makes it into an NES console emulator. After some work on the milling machine, a wooden box has room to squeeze in a few new components. [Bradley] originally planned to mount only an Arduino with an ArduNIX shield to handle the Nixie clock, but the emulator demands some space saving. Flipping the Arduino on its side freed up plenty of room and the shield still easily connects to the adjacent Nixie tube board.

A Raspberry Pi serves as the console emulator and was mounted close to the side of the case to allow access to its HDMI port. The other ports from both the Arduino and RasPi stick out of the back, including an extension to the Pi’s RCA video out and buttons to set both the hour and minutes of the clock. The two surplus NES buttons on the front of the case control power to the RasPi and provide a reset function for the Nixie clock.

If that isn’t enough Nixie to satisfy you, check out the WiFi Nixie counter.