efficient light sources

[trevor1]

What is the light source and driver with the best luminous efficacy in lumens per watt. I have a low voltage application - less than 40 volts. The light source must have a life of 10,000 hours. The operating temperatures are outdoor temperatures in the continential united states.
I need to deliver about 15 lumens per lamp. cost no more than $5 per lamp and driver. thanks.

 

[dpc]

How much light do you need and how much power do you have available at 40V? ac or dc?

The highest efficiency lights commonly used for outdoor lighting are low pressure sodium. I don't think you'll find a 40V ballast, but you could step up the voltage pretty easily.

This will give you highest efficiency, and the ugliest light.

It would help if we knew what you were trying to do and how much real estate you need to light.

Good luck.

 

[trevor1]

It is a dc application. Battery powered. Battery capacity is unconstrained. Lumileds led is the source that I believe has the best eficacy in lumens per watt. The circuit I have produces 8.77 lumens per watt. Listed light output/measured voltage / measured current.

I can't be any more specific about the shape and intensity of the light source. At this point, we are also flexible on color. As close to white as we can get.

 

[hbendillo]

You don't ask for much do you? The price you want for the lamp for the specifications you list does not seem reasonable. I think it would be much more. Philps Lighting and others are doing some exciting things with LED's. This should give you the lamp life you require and the requirement of only 15 lumens per lamp can be easily achieved. Many colors are available. They have a white source but it is not purely white. Companies are working on that and should be avaiable soon.