Pulling a scanner apart is easy: most models just clip together
and can be separated by the judicious use of a screwdriver. Inside you’ll find a
moving carriage on which the cold cathode fluorescent lamp (CCFL), focusing lens
and charge coupled device (CCD) image sensor are mounted. In addition, the
carriage contains two or three mirrors to reflect the image to the lens.
The carriage is driven by a geared-down stepper motor that
operates a toothed belt. There’s usually also a position sensor to detect when
the carriage is in its "start" position and, of course, the necessary image
processing circuitry.
So getting the bits is easy – but what can you do with
them?
The CCFL
The Cold Cathode Fluorescent Light (CCFL) is run by a high
voltage (HV) power supply which produces several hundred volts. Warning –
it’s high enough to give you a nasty shock or burn your skin! In fact, given the
right circumstances, a shock could be fatal.
Salvaging this part of the system is very easy – in most
scanners, the HV power supply is mounted close to the CCFL on the carriage or
alternatively, is mounted remotely and is connected to the CCFL via some HV
wires. The HV power supply is a separate circuit board and contains a
transformer, inductor, a few capacitors and some transistors.
