There are ppl that devolops video camera adapters, where you can mount a
normal 35mm system camera lens to a videocamera, and get the focus depth
used in filmmaking (background softed, impossible with videocameras) Its
spelndid when you want to attend the viewer of details in the film that are
imortant for a story etc.
Thing is that the image created by the lens is projected on a ¡°screen¡±
inside a lightproof tube, and the video records the image,m that now is
upside down and mirrired.
Now to the point.
A drawback is that the videocamera gets any surface patterns from that white
transparent screwn, dust etc, like a static background in the produced film.
The solution is to use a vibrator, and they often use a beeper, that device
ppl use instead of telephones. And they mount them inside the tube with an
ackumulator that is rechargable. The tube vibrates during takes, and you
cannot see anything but the nice film content.
So my hint is to use that device =)
Ref:
/Lars
-----Ursprungligt meddelande-----
Fr?n: TekScopes@... [mailto:TekScopes@...] F?r J
Forster
Skickat: den 29 december 2006 22:52
Till: TekScopes@...
?mne: [TekScopes] Chopper wanted (the electromechanical kind)
Hi all,
There used to be such a thing as an electromechanical chopper (AKA
vibrator), kind of like a relay tuned to operate at many 100's of Hz,
or faster. Airpax was a popular manufacturer. Tek used them in some
instruments (for example, part #119-0016-00), and I have a need for
one of fairly relaxed specs. Of course, I'd like to spend a little
money as possible. If you have one, please email me OFFLIST - thanks!
This will go into a piece of Tek-related equipment, by the way, if
that helps :)
Chris,
Maybe this is unnecessary, but there is a wide variety of the things
(I'd guess hundreds of types at a minimum). There are different coil
voltages, frequencies, contact arrangements, contact types, and
connection layouts (at least). Also, a chopper is not the same as a
vibrator. (the former is driven and for low level signals, the latter
self oscillating and for power.)
Also, if this is a new design, you really should consider using a FET
switch instead.
-John
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