Converting to LED warning lamps
original warning lamps in the instrument binnacle are very hard to see, especially
the main-beam lamp. I have already tried fitting 5w bulbs, but this doesn't
help that much and melts the housing!
The next step was to convert to Light Emitting Diode (LED) as they are now available in several colours, can be very bright and also produce virtually no heat. I have made replacement "bulbs" that fit into the standard holders using the following;
of stripboard (veroboard) 12 holes by 3 strips
2 x High-brightness LEDs in an appropriate colour
2 x 1K resistors
I used "water
clear" LEDs but these tend to produce bright spots due to their natural
focusing. I lightly sanded the ends with emery paper to create a diffuser,
but it would make sense to use diffuse LEDs to start with!
Bending the leads at a right-angle 4 or 5mm from the base of the LED, I fitted them to the strip board as shown, with both cathode (negative) leads in the centre hole. The cathode can usually be identified as the shorter lead and/or a flat section on the LED base.
thing is to dismantle the binnacle and remove the centre strip (with the warning
legends). Under this
strip are filters that give the lamps their colour. I think the aging of these is the main cause of the visibility
problems & suspect that the ordinary bulbs would be fine if fitted with new coloured covers.
Either way, the filters have to go.
You get no diffusing effect without the filters and, even with diffusing LEDs, you tend to get a bright spot of light, so I put some "magic tape" (the opaque sellotape that you can write on) on the legend strip - it works really well and gives a nice even brightness. You can see the mat finish effect in the picture as I haven't yet covered the indicator lamps.
Now for the LED lamps:
This is the result, which I think works well - it's hard to photograph lamps, and it looks better "in the flesh".
I'm sure there are better ways of achieving the same result; a single 8mm, high brightness, diffuse LED would probably be the best bet - I just used what I had around.