"Pszemol" wrote in message
...

They look like they are used. There are tracks goning from
these 3 towards the display, but they disappear under it...
There are three separate track going from them.
I was thinking it might be heater for the vacuum display cathode?
I have never repaired a device with VF-Display before, so
I am not sure of the circuit... Do you know any schematic example?
It looks like old, already "fogotten" technology today ;-)

What I am looking for is the place I can get replacement,
or - an idea on how to build similar circuit from discrete
components or other chip from different manufacturer...

I might be inclined to try to cobble together a regular AC transformer type
supply to keep this going.

http://www.allelectronics.com/cgi-bi...200&type=store
has a couple of converters, one of which (CAT# DC-32, "2 for $1") is
somewhat close, but it's either that or a new pH meter.

http://www.alltronics.com/power_sources.htm has some weird crap too (along
with annoying Java pages) but you'll have to poke around there for a while.

N