I was also planning on doing something similar, except that I was going to hook up the
oscillator thingy to a high frequency strobe light attached to my Dick Tracy wrist
radio
using a disco ball to reflect the beam from my high speed 1000gmHzah laser gun. <G>
Norm
Mark Roberts wrote:
> This is fascinating because it's pretty much how I was planning on setting up a
> shutter speed tester at home. The main difference is that I was planning on
> using an infrared LED emitter/detector pair (driven by an oscillator) and a
> frequency counter set up as a manually reset event counter. Think this would
> work?
>
> "David A. Mann" <[EMAIL PROTECTED]> wrote:
>
> > Basically all I did was shine a low-power laser into the shutter, with a small
> >silicon photocell on the other side, so the photocell gets lit up while the shutter
> >is open.
> >
> > Attached to the photocell was a digital oscilloscope in single-shot mode,
> >triggering off the rising edge. The 'scope has an automatic pulse-width
> >measurement so I just used that to measure how long the shutter was open.
> >The 10mW laser gave me about 400mV (or 0.4V for the non-metric) out of the
> >photocell so I had plenty of signal to work with.
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