I managed to pick up a few cheap VFDs (Vacuum Fluoro Displays), but the information about them is scarce. What makes matters worse is that I am a post vacuum tube era child, so my knowledge in the area of using and driving vacuum tubes is limited.
The display is labelled Futaba 11-ST-26ZA and a (joke) of a datasheet can be found here: Datasheet
The specifications from the datasheet are:
Ek: 4.5 VDC
Idigit = 1.3 mA
Vgrid: 12 VDC
Vseg: 12 VDC
So my understanding is that I need to do the following to drive the VFD with a micrcontroller of some sort:
Apply 4V signal between filament +'ve and -'ve terminals, limit the current to 18-100mA with a inline resistor appropriately sized, and use PWM at frequency of 15Hz and duty cycle 1/15. I was planning on switching 4V at required frequency and duty cycle through a MOSFET to the filament.
Apply 12 VDC to each segment I want to turn on (again, for instance via MOSFET switch).
Apply 12 VDC to the grid (digit) I want to turn on, as in 2.
Once I get the VFD working, I can implement multiplexing and driving the segments in the MCU properly.
Questions: Is my above plan reasonable? Do I need to somehow limit the current to the grid and to the segments (inline resistor - as with filament) or is this not necessary?
Thanks for feedback in advance! -Igor