Author Topic: IV-4 VFD Tubes and PT6312LQ Driver, Power, Etc  (Read 122 times)

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Offline zcomputerwiz

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IV-4 VFD Tubes and PT6312LQ Driver, Power, Etc
« on: April 06, 2020, 06:01:42 pm »
I'd like to build a retro style display for a prop. It doesn't have to show much, 4 characters. Will be using an Arduino for the MCU.
IV-4 VFD tubes were ( relatively ) cheap, the PT6312LQ seemed to have all the features I want, as it is capable of driving 4x16 segments without anything special as far as I understand.

I got a little ahead of myself and purchased parts, now I'm re-reading the datasheets and have some questions while things are still in shipping.

It looks like the PT6312LQ has a maximum grid / segment voltage of -25v, if Vdd is 5v.
Since the best case is 1/4 duty cycle with my configuration, and the IV-4 tubes are normally driven at 25v static or 50v multiplexed, will this make the tubes too dim to see?

I'm also not sure how the power supplies for these will work, as I'm having a hard time finding isolated dc-dc converters.
It is my understanding that if I would need -5v and +25v connected to the ground pin - and that this would most likely let the smoke out of the supplies if they are not isolated and connected to the same battery.

My source was planned to be 2x10-12v 6000mah battery packs in parallel to run the display and the rest of the components.

Would a simple solution be an isolated 5v supply for the logic side of the PT6312 and 6N137 opto coupler on the serial lines from the Arduino?
« Last Edit: April 07, 2020, 01:19:44 am by zcomputerwiz »
 

Offline zcomputerwiz

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Re: IV-4 VFD Tubes and PT6312LQ Driver, Power, Etc
« Reply #1 on: April 20, 2020, 10:58:34 pm »
Have isolated DC/DC converter, optoisolator, filament driver, etc. Now just waiting on the VFD tubes.
If it's too dim directly driven from the chip, I guess I'll use the grid outputs to run appropriate transistors or such to switch the higher voltage.
 


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