This week we try out the IN12 Nixie tube blocks we’ve been working on. They’ll be on display in the new workshop studio and at Maker Faire New York. We also light up a mini VFD we scored in Akihabara in Tokyo last year. Sorry about the poor lighting, new workshop will be up and running soon.
Over the years we’ve amassed an assortment of Nixie and VFD tubes. They’re cool devices, but mostly we hide them in the closet. Our magnificent nixie tube thing will put out tube hoard on display in the workshop, and we can take sections to Maker Faires too.
The Magnificent Nixie tube thing consists of 3 separate boards. A high voltage power supply, a chainable controller board for 2 nixies, and a carrier board that holds the delicate tubes. Files are in the forum, check out the video above, and read more about the design below.
We’ll be back next week with another workshop video, then it’s off to New York for the Open Hardware Summit and World Maker Faire. If you’re in the area please stop by the Faire. If you’d like to join our NYC food crawl (Wednesday night) or electronics and hackerspace tour (Friday) please give us a shout through the contact form.
Nixie tubes need 180 volt supply to glow. We use a switching power supply that boosts 12 volts to 180 volts.
The power supply board wasn’t our own design. We grabbed the open source PCB from Nick’s website. It’s Maxim’s MAX1771 booster chip is used, it’s actually quite expensive if you don’t sample it. The board will provide the high voltage necessary for our strings of nixies.
The control boards drive 2 IN12 nixies using a simple serial protocol. They can be chained together into a massive, customizable, nixie thing. The IN12 is very common on eBay and other sources at a low cost compared to other nixies.
Each board has two 74141 decade binary-coded decimal ICs that handle the high switching voltage of the nixie tubes. A binary value placed on the 4 control pins select one of the 10 digits inside the nixie. We’re actually using the Soviet K155D1 equivalent of this chip.
Two BCD chips can be controlled by the 8 pins of a single 74HC595 serial to parallel output chip. The 595 is cheap and readily available.
The holder board has cutouts and mounting holes for 2 IN12 nixie sockets. The first draft was a little tight so we have to file the PCB down by hand. We corrected the footprint in the Eagle Part post this week.
Other shapes of nixies can be accommodated in the same DP6060 standard board size, and stack on top of the existing control board.