[sdiy] Magnetic field

[WeAreAs1 at aol.com]

In a message dated 8/1/04 6:20:32 PM, jmahoney at gate.net writes:

<< > The advantage of magnetic is that you don't have to wire up the source.

:-)


Huh? I don't see the difference.


Whether the switches are optical, electromechanical, or magnetic, don't you

have (a) a signal and (b) a destination for that signal? Or, am I (as often

happens ;-) missing something basic? >>

With the magnetic system, you just use permanent magnets as the "source".  
They don't need to be wired to anything.

I do agree with Harry, though.  I think optical would be more reliable, 
predictable and consistent.  There wouldn't be as great a variability as to the 
position of the light sources or sensors as there would be with the magnetic 
system.  I'm guessing that there's a lot of variability in magnetic feild strength 
with those tiny magnets, which would require a lot of futzing, I think.

Sequential T8's had optical sensor keyboards.  I HATED working on them.  They 
were definitely not designed with the repair tech in mind.  I think the 
Synclaviers had the same keyboard mechanism as the T8, at least that's what I was 
told.

Michael Bacich