Change LCD to VFD

[Rob Northen]

I changed a 2x16 LCD with a 2x16 VFD in my alarm system.
It works just fine, but I got a question.
When you press a key on the keypad, the LCD backlight turns on.
These leads are of course not needed with a VFD, so I've connected these two wires to a little relay, that switches the 50v from the VFD transformer on and off. So, everytime a key is pressed, 50v is passed to the dispaly, and when you log off, 50v is shot off. This is done to incresae the life of the display.
But, is there something wrong with this, can you see any problems or is ok ?

[hardwareguy]

Re: Change LCD to VFD

I see no issue with this at all.

Keep in mind that VFDs have lifespans exceeding 20 years in continuous operation.

[Rob Northen]

Re: Change LCD to VFD

Thanks

Was just thinking it might hurt the filament

[Agent24]

Re: Change LCD to VFD

Might make some kind of difference to the life but probably nothing noticeable or anything to worry about.

[b700029]

Re: Change LCD to VFD

The filament uses 50V?

That sounds more like a plate voltage, and leaving that on won't change the life of the display much.

[Longbow]

Re: Change LCD to VFD

Rob, I'd like to hear more specifics on your project. What prompted you to change the display type? An LCD driver IC cannot be used to drive a VFD, so this sounds like a lot of re-design and changing IC's.

[Rob Northen]

Re: Change LCD to VFD

Rob, I'd like to hear more specifics on your project. What prompted you to change the display type? An LCD driver IC cannot be used to drive a VFD, so this sounds like a lot of re-design and changing IC's.

I changed it, because VFD looks WAY cooler, only reason.
And it was not that much work. I bought a Futaba VFD with LCD emulator, if the LCD and the VFD board have had same size, then it just been a swap.
I had to change the mounting a little. And luckely, the 5v supply was no problem, plenty of juice.

This is the VFD;
http://dk.rs-online.com/web/p/vakuum-lysroer/6659771/

I have also just finished my own hardware/software project with a 2x40 VFD, and the code will run a screen saver every 30mins, that first clear screen, then light up each character one by one and then goes back to normal display mode.