light bulb watts to lumen ???

[sweetk30]

whats a good simple way to tell if you have a correct lumen count to be the same or more to the old watts bulb spec ?

I am trying to upgrade a lightbar ( cop/fire/ems ) from halogen to led to drasticly drop the amps needed and also get brighter output.

also some led bulb sales pages are not showing lumins but led count and style of led used .

going to try ebay special led units first to see if it works and how long they last then if like it later after the ebay special bulbs die will get good ones.

need to swap out h1 ( 55w ) halogen and 795 ( 50w ) ( 1156 base ) bulbs.

 

[dyeager535]

I found this http://www.rapidtables.com/calc/light/watt-to-lumen-calculator.htm but looks like you need more info, which also seems hard to find.

From what I have seen, SMD 24-36 volt bulbs are going to be bright. But obviously require a step-up converter. LED's of that size draw 20W+ and require heatsinking. Airflow seems to be a potential issue in a "sealed" setup.

Of all things I'm working on headlights for my Daughters powerwheels, so bought some 10W/12V and 20W/24-36V SMD's. The 20W's are painful to look at but have not received the 6A step up converter I ordered yet. The 10W are bright, but I don't think they would be worthwhile on a real vehicle. The 20W bulbs are nearly as large as the palm of your hand.

Can probably find them cheaper, but here is one source: http://www.ebay.com/itm/HOT-new-Bri...arts_and_Accessories&var=&hash=item3f38b387d2

Perhaps with existing housings if so inclined you could make a setup that would be sealed and still heat sink well, if you didn't want a pre-created solution.

 

[Blue85]

This is from Answers.com:

Incandescent: 10-12 lumens/watt
Halogen: 15 lumens/watt
CFL: 50-60 lumens/watt
LED: 50-60 lumens/watt, some manufacturers claim more.

You'll have to get more date from the LED manufacturers, though, since some LEDs are getting closer to 100 lumens/watt (almost as good as metal halide) and the overall efficiency is all over the map on LEDs. LEDs usually perform better than halogens at the same total lumens, since they are inherently directional and lose less in the reflector and optics. So you wouldn't need quite as many total lumens.

With no other information it looks like 1/4 the power would get you in the ball park.

 

[dyeager535]

Got the step up converter yesterday and at around 26V looking at them (through fairly clear plastic) leads to temporary blindness. Literally.

Once I get this thing done, I'll see what kind of range you can get out of them near 36V. Pretty hard to determine lighting efficiency in actual application, unless you can compare directly with another light source.

If my math is right, a 6A step up converter should be able to handle four twenty watt LED's.

No idea what pre-made stuff sells for, it will require some time/effort to wire up and integrate something like this into a light-bar.