Oldham Lamp Replacement Boards.
This PCB contains 24 x 5mm LEDs and replaces the 2 bulbs fitted to the standard Oldham headset. It is intended to be run from an Oldham/Exide 4v Lead-Acid battery. The modification involves simply removing the reflector assembly and connecting the 3 flying leads to the existing terminations within the headset shell.
The
modification which utilises the switch on the Oldham headset has two light levels
and offers a significant reduction in current drawn from the battery. In 'main
beam' mode all 24 LEDs are on and the current draw is about 600mA. In 'pilot'
mode, the number reduces to 4 in a similar fashion to the Oldham headset, here
the current drawn drops to 100mA.
(For comparison, the oldham incandescent lamps draw about 1A and 300mA respectively depending upon exactly which bulbs are fitted).
This board can be built to operate from a 3.6v NiMH or 3.7v Li-Ion battery - specify this when ordering. If ordered to operate from 3.6/3.7v, the addition of a silicon diode in series allows use with an Oldham Lead-Acid battery - the best of both worlds!
This modification can be done as a DIY
or I can carry out the modification for you. The
PCB is £20.
The photo right shows the simple connection requirements - 3 flying leads with tags connect under existing screws. The existing switch is retained and no irreversible modification to the headset is required.