Initial results were
encouraging but the image was very susceptible to changing light
levels. This was in the main, caused by the close focus and there
close proximity of the CentreCam body to the work piece. This
necessitated a long angle light source which gave rise to glints and did
not illuminate the work piece that well.
|To overcome this problem a built in light
source was considered. After some experimentation, a ring of six
LEDs were added and powered via the Webcam USB interface.
The components used are shown opposite; 6 while LEDs, 6 series
resistors and a circuit board.
The circuit board was cut from single sided copper clad board and the tracks were milled out rather
than using conventional printed circuit board technique.
||The components were soldered
on the copper side to ensure the underside was flush and the system tested
with a 6 V battery.
|To hold the LEDs an aluminium ring was
manufactured. The circuit board and mounting ring fitted into the
existing housing as shown below.
||The original two part housing was turned out
to provide space for the circuit board and the power supply connected to
the webcam circuit board.
The whole units was assembled and tested.