101Views4Replies

Author Options:

What is the proper way to operate the grids on a VFD? Answered

I have a VFD removed from an old DVD player, and I am currently trying to construct a driver for it. So far I have worked out a the pinout and a suitable cathode heating voltage and have determined that 20-30V is sufficient to properly light all the segments.

As for the grids, I am unsure what the proper voltage to apply in order to light/blank each section. Currently, leaving the grids unconnected or at 0V effectively blanks all segments, and connecting the grid to the anode voltage lights the section. However, other designs seem to put the grid to 0V to allow the section to light and apply +/-15V or so to absorb/block the flow of electrons and prevent the section from lighting.

Is it alright to pull each grid high and connect it to 0V to blank the section, or will there be problems when trying to drive each section?

Thanks in advance for any help.

Also, is it worth the extra circuitry needed for an AC heater voltage for a display this size (under 4.5" x 1"), if so, what is a suitable frequency?

Comments

The forums are retiring in 2021 and are now closed for new topics and comments.
0
frollard
frollard

Best Answer 8 years ago

I don't know, but I found some good info here:

http://www.microchip.com/forums/m202829-print.aspx

0
The Skinnerz
The Skinnerz

Answer 8 years ago

Thanks for the link.

One of the application notes linked from that page has confirmed that 0V/anode voltage on the grids is appropriate, and has also made some interesting points on supplying AC to heat the cathode.

0
iceng
iceng

8 years ago

Have a look at the " DVD Player Hack " top of the right side of this page.

A

0
The Skinnerz
The Skinnerz

Answer 8 years ago

Actually, I saw that one on the newsletter this week, and that was what made me remember that I had a display like that. Unfortunately, I only have the display itself, it does not have a driver or power supply with it.