Ice Tube Clock without MAX6921??

[Agent24]

I'm thinking of making an Ice Tube Clock but I've run into difficuilties sourcing the MAX6921 VFD driver IC.

Then I came across this in the design notes: "We could use high voltage transistors and use those as buffers but that would take a lot of space"

In fact, someone has a similar design using the same tube but which uses transistors (http://web.jfet.org/inGrid/)

Now I don't really care about space filled with a lot of transistors if it means that the thing would actually work without trying to get an elusive MAX6921 - although that may actually happen if I'm lucky... but I'm not going to count on it so I'm looking at alternatives.

What kind of changes would have to be done to the design of the Ice Tube Clock to use transistors instead of a MAX6921? Can anyone help me on this? How easy would it be?

[ghostfish]

Digikey has it available in single unit quantities.

[Agent24]

I keep forgetting to tell people I live in New Zealand. Digikey want $50 shipping for anything outside USA it seems

[Technics]

If you want to go half way between the sinlge chip solution and individual transistors you could use these http://www.futurlec.com/cgi-bin/search/qty_price.cgi?part_no=TD62781AP. Two chips would allow you to drive the IV-18 tube and the shipping is a lot cheaper than Digikey. I used these chips for a 4 digit IV-12 VFD clock design.

To use these IC's or discreet transistors you'd either need to use an external shift register (or a decoder like in your link) or a microcontroller with more pins. Shift registers are good because they can be driven by the SPI peripheral. A total of 16 ouptut pins would be required just for the display, 8 for the grids and 8 for the segments. It should be easy enough to modify the Ice Tube code to use this type of drive though.

If you haven't done anything like this before it would just be easier to order the kit unless you're willing to make and learn from mistakes. If you have you'll be fine.

[spikey]

hi

I honestly think u are done with your project allready, but google search brought me here, while lookng for something similar ...
For everyone that cant get a hold of the 6921, there is a chance to get it.

maxim samples.
those guys were kind enough to send me two of those chips *happy* *happy*

free postage, and im from Slovenia. Im guessing no one here has ever even heard of it haha.

anyways, the package u want, might not be available for sampling, but try to get the that sits in the PLCC socket, or even better get a through hole one. I got the AUI+, that is freakishly small, but its nothing a little solder wick couldnt fix

[adafruit_support_rick]

im from Slovenia. Im guessing no one here has ever even heard of it haha.

Hey! We know where Slovenia is. My daughter has even visited there. Said it was very nice.