Well, I’ve been at it again. I found a cheap lot of 50 NIXIE Tubes online and split them up with a buddy. Thus, many more NIXIE projects (mainly clocks) will result.
Not much progress yet as I only got the tubes this afternoon, but I rigged up a quick and dirty power supply tonight to test one out. Here are a few quick pics I took during my bench tests.
NEON counter circuit built on a solderless breadboard
Just a simple little project this time. I wanted to build a project that would be more of an art piece than anything, I had an idea for a wooden frame with plexiglass in the front and back, showing off some sort of electronic gizmo inside. I always liked the look of NEON and I knew somewhere I had a bag of NEON bulbs with no set purpose. So, I devised a small circuit with a micro-controller to run 4 NEONs, they simple run through several patterns written in my software. The pushbutton controls and interrupt which will advance to the next pattern if pressed. If left to run free, there is an internal counter which allows every pattern to run X number of times before triggering the interrupt through software and advancing to the next pattern. Currently, for testing purposes X = 4, but when it is all said and done I plan to make X = 10.
This circuit is still in the semi development stage, so there is not yet a PCB for it and no enxclosure has been constructed. Once the circuits works to my satisfaction, a PCB and enclosure will be constructed.
Stay tuned for updates as this project continues!
Click the link to see the circuit in action! -> NEON Counter / Sequencer
UPDATE! – April 4th
I was able to go into the lab and make the PCB this morning. Below are a few shots of my work.
Fully populated PCB
Initial test of the new PCB
UPDATE! – April 9th
I started building a case this morning for the circuit. It is built out of the same material as the NIXIE Bar Graph project, so the two will match when all is said and done. Here’s a photo of the pieces roughly cut out and attached. I still need to sand the entire assembly and cut out the front and back windows. Once I do that it will take about a week or so to stain.
Enclosure construction begins......
UPDATE! – April 17th
The project is complete! After a week of staining the enclosure is finished. Sorry for the bad photo, with the front and back being plexi-glass it was extremely hard to take a picture of.
Final Product
Completed NIXIE Tube Bar Graph (IN-9 tube)
NIXIE Bar Graph
Well, after building a few NIXIE tube clocks I fell in love with the technology. I was toying with the idea of ordering more tubes for another clock when my friend e-mailed me a link to some NIXIE Bar Graph tubes. He said he was going to order some and wanted to know if I’d split the order with him. So long story short, I did. When the tubes arrived we had no clue what to do with them, all we knew was you varied the current to change how much of it lit up. I decided to use one of my tubes to make a simple display that simply goes up and down. Just a little eye candy, and hey, I got to build something! After some experimentation I got a circuit working to my liking, designed a PCB and put it all together. While this circuit does a simple task, it is no so simple in terms of construction. The tube, much like the ones in my clock, required the 150-170vdc to light up and the logic is again running off 5 volts. To solve this problem I designed a multi-voltage transformerless power supply to give me 5volts (Microcontroller), 12volts (Op-Amp) and 160volts (Tube). Simply put the microcontroller outputs a PWM signal that shifts from 0% – 100% and back, the Op-Amp is wired to a high voltage transistor (MPSA42) in a voltage follower configuration. The PWM signal is fed into an RC low-pass filter to simulate a DAC (Digital to Analog Converter) and that output feeds the control input on the voltage follower. The voltage follower is wired such that it alters the voltage presented across a fixed 470ohm resistor which, through the transistor, is in series with the tube and thus controls the current that is allowed to pass through the tube. (I=V/R).
NIXIE Bar Graph circuit board
Click here to see the unit in action! NIXIE Bar Graph