Wednesday, 5 May 2010

A Pirate Calls

For some time I've been wanting to replace the 12v filament bulbs aboard Starcross with less power-hungry and more modern LEDs. My initial experiments proved disappointing in terms of light output and the first ones I tried have long since been disposed of .
About half of the lighting on the boat is in the form of "bus bulbs" (and yes, I am old enough to remember when they were actually fitted to buses). They give out a pleasant, yellowish, light but consume lots of power in doing so. Its taken a while, but recently, LED's to a bus bulb design have become available and I've been trying them out. Firstly, I tried one of these, an 18 SMD LED fitted with 50mm square LEDs from Puffer Parts

They give off a surprising amount of light - as much as a filament bulb - and the light quality is almost as "warm". The exposed diodes, however, can be a little harsh if not diffused by the lamp shade and, more importantly when switched on they interfere with the reception on my analogue radio to such an extent that it becomes unlistenable to. So when I heard that Baddie the Pirate not only sold bus bulb style LEDs from her boat and via her website but was planning to visit Norbury Junction last Saturday I got in touch and she (Baddie is a very friendly she-pirate) agreed to bring some samples round to show me.
Baddie's bus bulb replacements are a different design with 33 "small" LEDs and look like this
The glass domes, particularly the pearl version, make them look like "proper" bulbs and the light quality they give out is, if anything, warmer than my filaments, with a rather pinkish tinge to it. I was pleased to see that they caused no interference to the radio at all, but a trial after dark showed that they did not emit enough light for Starcross' main living area. The one I bought has therefore been transferred to the bedroom, where it is quite adequate (and the pink glow somewhat romantic!) but I won't be buying any more.
LED technology continues to improve in leaps and bounds and I'm sure it won't be long before someone comes up with a design for a bus bulb replacement that combines the best features of both these bulbs to produce a high-output, warm, interference-free replacement for the trusty bus bulb.


Captain Ahab said...

I hoped you had found a solution, but actually its just a cul de sac!
Fulament bulbs are horribly power hungry.

Halfie said...

It's the first I've heard of radio interference from LED bulbs. I suppose it's from the voltage converter and stabiliser within the unit (to take the raw "12V" and convert it into the 2V or so which individual LEDs expect.)

Starcross said...

Thanks for the comments guys. Strangely, the interference only affects the (older) Sony radio/tape player and not my pocket-size Roberts radio, so perhaps the problem lies with the radio rather than the LED?