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Hard Disk Drive
Description:
“We have
developed a high-speed laser
shutter based on voice-coil
actuators found in generic
hard disk drives. We have
enhanced the shutter with a
new driver circuit described
below and a notched flag,
achieving 500ns rise time and
sub-microsecond pulse
durations. The shutter is
readily constructed from a
disassembled hard drive (as
shown in an early prototype in
the photo above), with the
addition of a simple drive
circuit. A high-current opamp
(e.g. L165V or OPA548) can be
used, but requires a bipolar
power supply, and generally
some sort of pulse shaping.
The circuit in our paper,
designed by Sandor Szilagyi,
provides very fast switching,
a small holding current, and
bidirectional drive from a
unipolar supply.”
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