Showing my current project, duo IV-22 VFD board. - Page 1
Forum section: electronics / projects

author: Rolo
author_rank: Regular Contributor
timestamp: September 01, 2018, 06:28:38 am
content: Would like to share my current project, been working on it some time and now I can show some results.It's a board that contains two IV-22 VFD tubes, with power supply and shift logic on board.I like VFD displays and got some inspiration when reading this project :http://www.nixieclock.org/?p=411The board is designed to run on 5V DC and drives two IV-22 tubes in static mode. It contains a 20 bits shiftregister,buck convertor for the filament voltage of 1.25V and a boost convertor for the anode and grid voltage of 28V.They are high efficiency convertors to keep the power consumption a low as possible.The display can be dimmed using PWM on the blank input of the shiftregister and there is a shutdown input,when the controller sets this to HIGH the buck and boost convertors are switched off.Leaving it unconnected the power on the module is ON.The board is connected trough a 10 pin 2.54mm (0.1 inch) header, it can be a straight or angled header, depending on how the board is build into a case or on a stand. It's breadboard friendly because of the one row header.It has 2,5 mm mounting holes on the corners, 1.6 inch in square, the headers are in the same 0.1 inch grid as the mounting holes so they fit on the well known green prototype boards.The boards can be cascaded by connecting data out to the next data in. It also has a 5mm RGBW led behind each tube. This is the neopixel type en it is also chained to the next board. I choose the natural white version, this gives a nice, warmer type of white light compared to the RBG composed white.Adding the leds was a choice to give me the option to use them on the same pcb, I have to experiment a bit with how it looks in real life. It can also be handy to work as status indicators for the controller. Now i'm going to do some programming to get this hardware working, I have have two modules connected to an ESP32 dev board and the basics work.Thanks for reading, if you want more details, just ask.Some pictures :

author: bloguetronica
author_rank: Frequent Contributor
timestamp: September 01, 2018, 08:50:57 am
content: Nice! Where did you get those VFDs? They look like Nixie tubes at a distance.Kind regards, Samuel Lourenço

author: Rolo
author_rank: Regular Contributor
timestamp: September 01, 2018, 09:32:35 am
content: These VFD's have the same housing and pin layout as the IN-12 nixie tube, that explaines why they look like nixies. The IV-22 are available on ebay, or herehttps://tubes-store.com. They were made in large quantities but most are stocked on shelves in Ukraine. So a lot of new old stock is on the market now. They do have their own special needs, mostly the pins are a bit corroded and the backplane can be different colours due to aging in different conditions. Also the glass housings are not 100% the same, you can see that the production tolerances were big. But that's the charme about these tubes.

author: Rolo
author_rank: Regular Contributor
timestamp: September 01, 2018, 09:42:14 am
content: Short demo of two boards on a ESP32 dev board. Hard to get it right, my phone's camera picks up the VFD's light a bit to bright:https://youtu.be/8FQR283nqSs

author: Gyro
author_rank: Super Contributor
timestamp: September 01, 2018, 09:52:58 am
content: Nice. All you need to do now is ditch the LEDs.

author: Rolo
author_rank: Regular Contributor
timestamp: September 01, 2018, 11:07:16 am
content: Quote from: Gyro on September 01, 2018, 09:52:58 amMust say that in real life the white does look good, on low brightness it gives the tubes a bit of a vintage glow. The colors are a bit too, you know.... I think the colors are usefull to act as status indicator, for example a NTP clock thas is doing a scheduled sync.I did hesitate to place the leds in the design, but they are cheap and take no extra pcb space. I do not have to use them and placing them afterwards requires a new PCB.