-----Oorspronkelijk bericht-----
Van: cctalk-bounces at
classiccmp.org
[mailto:cctalk-bounces at
classiccmp.org] Namens Jos Dreesen
Verzonden: woensdag 30 december 2009 14:18
Aan: General Discussion: On-Topic and Off-Topic Posts
Onderwerp: Re: HP Integral / display schematic ?
I assume you mean that the power rails were fine,
and there were
sensible waveforms on the other pins.
Indeed, voltages ok and syncsignals as described in the HP
Journal article.
The small PCB mounted on the back generates a
blanking signal that
was also correct.
Right. It's neen a long time since I've looked at one of these
displays. Is this a little PCB on top of the display PCB itself?
No, it is a small PCB mounted on the plastic frame, and it
contains 5 TTL to calculate the framing signal from H and V
sync. Should have been done in the displaycontroller imho.
> This was indeed the culprit : it is a 5V to
5V isolation
converter,
used to
power some logic that is required on the far end of high
voltage
Where does it get the HV from? It must be generated on the
display board itself.
The very small pcb mounted on top of
the displaycontroller
board is the 5V convertor.
The high volatge is probably generated with the small
transformer on the big board.
> I would still be interested in any schematic
of the driver
> electronics of any Epson electroluminiscent display
Of course is is actually a
Sharp display...
Still would like to know why it needs a CPU & Eprom, since it
has already all required signals.
Jos
Mine is working fine until now..
When I got mine it wasn't used for several years, and I got the Idea it
wasn't used much in the years before. And I did checked the screen signals
and had the idea it was the HV-supply not having a high enough voltage to
ignite the screen cells.
Or one of the little japanese who live in old electronics wasn't awake yet
;-)
Never the less after letting it (by accident) on for a few hours the screen
switched on. And it stays working..
Did you read the HP journal article about the Integral ?
It describes the engineering background of the Integral.