[H-GEN] onefang's theory of monitor speed. Was: flat panel monitors with Linux?

[Christopher Biggs]

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I wrote:
>
> One upon a time hsync ranges were maybe 25-35khz and vsync were
> 25-50Hz, nowadays the possible ranges are more like 25-200khz and
> 25-160Hz, so the scope of analysis that the monitor has to do to "lock
> on" to the video signal is VASTLY expanded.

Plus, to even *achieve* such a wide range of frequencies (remember,
this is _all_ done by using magnetic fields to *bend* (!) a beam of
electrons that is slamming into a phosphor-coated piece of glass just
a cubit or so from your face), the transformers in the beam driver
electronics must have multiple windings, and hefty transistors or
relays are used to switch in the correct set of windings to achieve
the required frequency range.   

Magnetic fields produced from coils do not change instantly, in fact
they "resist" change.   It takes a while for the new field paramters
to stabilize.   That's the click or even *CLUNK* you hear from a
monitor when it re-syncs; a combination of the windings being
switched, and the transformer armature tending to fly across the room
due to back-EMF.   CRT monitors are steam-era technology at heart.

(Now I'm getting way out of my
software-geek-who-knows-a-bit-about-electronics depth!  Anyone with
engineering qualifications want to take it from here?)

--cjb

-- 
It's boring being a program when your only job is inserting a random .sig.
Muggins thinks I've put his .sig here, won't he be surprised...


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