0

#Macro Monday: Ice Tube Clock

vfd1_600

The Ice Tube Clock, available as a kit, uses a lovely IV-18 vacuum-fluorescent display (VFD) tube.

vfd2_600
Unlike Nixie tubes, which are current-operated gas-discharge displays, VFDs are thermionic voltage-controlled devices, just like the vacuum tubes used in old radios and amplifiers (as well as some modern high-voltage equipment). Specifically, VFDs are a special kind of directly-headed triode.

VFDs have three basic parts: the filament (cathode), the grid, and the phosphorescent anode(s). In the case of the IV-18 device used in the Ice Tube, the entire tube has two filament wires stretching the length of the tube (wired in parallel). Each separate digit has it’s own grid, and each of the 7 segments of the number display are ganged together is an anode. By quickly multiplexing the grids you can make the device appear to display all the digits at once.

In this photo you can see all three electrodes. Those two dark lines running horizontally across the photo are the filament wires.

vfd3_600

Here you can see a couple of illuminated digits. The nebulous nature of the illumination across each segment is caused by variations in the electric field, and the grids casting an electron shadow onto the segments.


Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Join 14,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

CircuitPython 2019!

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7:30pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/


Maker Business — A list of companies owned by Amazon. It’s big.

Wearables — Raid the kitchen

Electronics — Capacitor ESR

Biohacking — Vitamin-C + Gelatin for Accelerated Recovery

Python for Microcontrollers — Python snakes its way to the STM32, Serpente, and more!

Adafruit IoT Monthly — Adafruit IO Updates, RGB Stream Deck Message Panel, and more

Microsoft MakeCode — Welcome to the MakeCode Newsletter!

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !



6 Comments

  1. I was wondering if it is possible to buy just the tube (and the breakout board), as my ice tube clock fell two weeks ago and the tube shattered inside the acrylic box. I could order the IV-18 VFD retro display from ebay, but I’d rather continue supporting you guys.

  2. @steve: yup! http://www.adafruit.com/products/242

    also, the tube PCB: http://www.adafruit.com/products/343

  3. Thanks johngineer! I searched the site but couldn’t find them, awesome, now I’ll be able to tell time again!

  4. bill earl - adafruit_support

    Nice work John! Putting those T&S bellows to good use I see. Is the second photo taken through the glass, or did you remove the grid from a broken tube?

  5. Thanks, Bill!

    For the second photo, I grabbed one of the tubes that didn’t pass QC and cracked open the glass envelope.

  6. very nice. might get this kit. working on a numitron tube clock at the moment, similar era, different technology. love old fashioned displays. 😀

Sorry, the comment form is closed at this time.