Ok ok. This is fun. But I'm really looking for info on the lamp's focusing knobs. Specifically on the white plastic cover that covers the knob that controls how close/far the lamp is to/from the lens/screen. Even more specifically I'm wondering if the loss of this plastic cap (like for example if it melted due to heat) is a big deal.
Asking for a manual was sort of a bonus (to myself/Cinematheque) because once we had one, lent it, and didn't get it back. Anyone plastic cap folks out there? Steve On Sep 18, 2017 7:22 PM, "Scott Dorsey" <klu...@panix.com> wrote: > What's wrong with the xenon lamp circuitry? > > It should be a constant current source, combined with a little high voltage > supply to strike the lamp. When the high voltage pulse makes the thing arc > over, the plasma between the contacts is conductive so all of a sudden the > thing turns into a low resistance device and it only takes a couple hundred > volts for the arc to be sustained. The constant current source means that > the thing remains at the correct operating point as the electrodes slowly > burn away. > > I _think_ that the EX-2000A uses trick magnetics to do the job... it's a > big saturable reactor that acts as an AC constant current source, then > rectifiers to turn it into DC, and then a filter capacitor made with > multiple capacitors and inductors in a chain to eliminate the ripple. > > You could talk to Steve Guttag, I know he has worked on those occasionally. > There isn't much to fail non-catastrophically. > --scott > _______________________________________________ > FrameWorks mailing list > FrameWorks@jonasmekasfilms.com > https://mailman-mail5.webfaction.com/listinfo/frameworks >
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