Working With VFDs

December 25, 2008 by Eliot 12 Comments

vfd

We love old display technology, like Nixie tubes, but they’re often difficult to work with because they require higher voltages than digital logic. Vacuum florescent displays (VFD) fall into this category. While not necessarily “old”, they are becoming far less common than LCDs. The main benefit of a VFD is that it actually produces light directly; it doesn’t require a backlight. You’ll find these displays on various players and appliances: CD, DVD, VCR, microwaves, stoves, car headunits, and others.

[Sprite_tm] had written off some VFDs, but recently revisited them with renewed interest. He started by testing what sort of voltage would be required to drive the display. It took 3V for the filament plus 15V to drive the grids. There are VFD controller chips available, but he wanted to get this working with what he had on hand. He had experience with older 40xx series logic, which can be powered by much higher voltages than 5V 74xx. His final schematic has three 4094 serial to parallel chips with an ATtiny2313 controller. A 5V power supply is dropped to 3V with diodes to drive the filament while a boost converter brings it up to 15V for the 4094s that switch the segments. While the code is specific to this display, it would be a great place to start your own project.

Disposable Camera Nixie Tube Driver

December 12, 2008 by Caleb Kraft 10 Comments

nixie_camera

Disposable cameras are quite cheap, and include circuitry that produces very high voltages. Because of this, they have been harvested for many projects. We’ve seen them used for coil guns and large high voltage power supplies, even for fixing rechargeable batteries that won’t charge. The latest in the long list of uses is to create nixie tube drivers. [the_don125] shows us how to use a single disposable camera to power 2 to 3 medium sized Nixie tubes. Be careful, as we said before, this project deals with high voltage.

Victorian Nixie Tube Clock

July 14, 2008 by Caleb Kraft 8 Comments

[John Clarke Mills] has pieced together this tastefully done Victorian style Nixie tube clock. He picked up a kit from nixietube.com and an old clock off of eBay. A little bit of elbow grease and solder later, he has this very nice mantle piece. Well done.

For those unfamiliar, a Nixie tube is used for displaying numbers or letters. They are a glass tube, filled with a gas (usually neon). There are metal structures inside that glow when electricity is applied. First widely used in the early sixties, Nixies were pretty much replaced when LED technology got cheap.

We noticed that nixietube.com was down, so you might also check TubeClock.com and neonixie.com for kits.

If you’re looking for more inspiration, read about the Nixie counter clock, Russian vfd, and the 6502 driven Nixie clock all previously on Hack a Day.

[via Retro Thing]

Multiband Nixie VU Meter

June 13, 2008 by Eliot 4 Comments

This VU meter project by [Daniel Naito] is a great piece of Russian electrocouture. It’s made up of 14 Nixie tubes that display seven frequency bands for the two audio channels. He found this similar project, but wanted to keep the cost low by avoiding such exotic ICs. First, the two input channels are amplified and then split using seven bandpass filters covering 60, 150, 400, 1000, 2500, 6000, and 15000Hz. Then, the AC audio is converted to DC. The final stage converts the logarithmic scale to a linear output. Besides the semirare Nixie tubes, the majority of the parts are just cheap opamps and comparators. The post is an excellent read and you can see it in action in the video below.