PBO, LED lights project, July. Electronic engineers please!

[Huscombe]

We\'ve met.

Not saying where nor when.

We design and make LED drivers for serious applications. With respect even Nav lights and true dimming cabin lights on boats is somewhere between Friday fun and as trivial as the article itself.

 

[alan]

I think the responses provided so far give the answer to your question; if you want a kitchen project just for fun then have a go at building lights as described. If you want to make some lights that you will use for navigation or even interior, then go for a professionally made one - some are not that expensive, because there is more to the design and construction than is obvious at first. I think the PBO article simplified the situation a little too much.
After looking at various options in ready made lights I recently bought some from Bebi and I thought these were very good, reasonably priced and made for the purpose. No connection with Bebi other than as a satisfied customer.

Alan.

 

[pappaecho]

Re: You have only brushed the surface

Two years ago I got pretty fed up with the brass overhead cabin lights with a 10 watt festoon bulb in them. I pulled out the entire bulbholder and made up 50 white LED array with 7 red leds to make the light a bit less white, I made up a simple plastic disc drilled to take each led, and connected 5 leds in series with one resistor (1/4 watt) and then cascaded the connections round the plastic disc.
With glass diffuser back in top the result is a light which is as bright as a 10 watt festoon which draws just over 1 watt, and runs totally cold. We were also able to point the leds in different directions so that the light output was diffuse.
We always leave one or two light on, if we leave the boat during the evening as the current draw is minimal .
We have also tried LED car bulbs in white, which replace the 10 watt bulbs in other fittings. However they work fine, but the light output is highly directional as each LED has a very limited angle, and as they all point in the same direction the light is very concentrated. Hopefully somebody will come up with an array where each Led points in a different direction, so giving a much more diffuse light.
In conclusion you get absolutely no heat production and the same output for about 10% of the current draw of a tungsten bulb. The arrays will never need to be replaced because the LEDS have an MTBF of 10,000 hours or more, and even if a few fail, it make little difference to the light output. The white light is at the blue end of the spectrum and is very "cold"