Re: Electrostatic deflection?

On Fri, 22 Oct 1999 08:57:27 -0400, you wrote:

>
>I fully admit that I'm out of my league in these discussions...don't
>let these musings slow anyone down...
>
>I was thinking about the yoke issue, and am wondering if it's
>feasable to modify a vector (or raster) monitor to do electrostatic
>deflection. I think this is what oscilloscopes do.
>
>I can see a nice, simple assembly of four plates replacing a yoke,
>but I'd imagine you would need higher voltages to acheive decent
>deflection. After all, oscilloscope tubes are long and skinny.
>I think the nice part would be driving a high impedance instead of a
>low one...
>
>Is this possible or am I just dreaming? ;)

It works great, though I think the plates would have to be inside the
glass, the closer to the beam the more effect on it's travel. I
believe the charge on the plates will be subject to the inverse square
law, though I could be wrong about that.

I have two X/Y monitors at home, one (an Tektronics) with about a 6"
diagonal screen and the other (an HP) with a 12". It's a *great* way
to run a B&W vector game, if you build an adaptor for the Z
(intensity) channel. The slew rate is *way* beyond that of a typical
yoke. More like a scope.

The 6" monitor is about 2 feet long, but the 12" is built like a small
TV. They must use higher voltages for deflection to keep the tube
short. (To tell the truth, the I've never seen the 12" work, it has a
high-voltage problem I didn't have time to get into before everything
went into storage. I do have the full schematic and specifications
for it though.)

-Zonn
Received on Fri Oct 22 11:16:03 1999