# Online LED runtime calculator - like LED Pro



## penquissciguy (Feb 23, 2008)

I've been on school vacation this week and decided it might be fun to tinker with some javascript programming. I like the LED Pro program for calculating runtimes, but I usually am on either a Mac or a Linux machine. So, I wrote a little javascript page that does the same thing as the runtime part of LED Pro. You can find it here. I hope someone can make good use of it.

Ken


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## spencer (Feb 23, 2008)

Neat. Well done.


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## LukeA (Feb 23, 2008)

bookmarked


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## ifor powell (Feb 23, 2008)

cool, just checked what it thought cappacity was as I had not bouthered to work it out afer a runtime test.

If your open to improvment I think an led count multiplyer for the vf would help out I was having to do that bit in my head but I know what the average is for the individual leds I am using. Possibly the same for the cells....

Good stuff :twothumbs

Ifor


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## penquissciguy (Feb 23, 2008)

ifor powell said:


> cool, just checked what it thought cappacity was as I had not bouthered to work it out afer a runtime test.
> 
> If your open to improvment I think an led count multiplyer for the vf would help out I was having to do that bit in my head but I know what the average is for the individual leds I am using. Possibly the same for the cells....
> 
> ...



I'm always open for improvement - just ask my wife! 

You're the second person to mention the led count to me. I may have to implement that.

Thanks for the compliments everyone.

Ken


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## penquissciguy (Feb 23, 2008)

I've added the ability to calculate the Vf of a series of LEDs and the combined voltage of a number of cells. Fill in the two values needed for either calculation and click the <<< button. It will enter the value into the form for you.


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## Gunner12 (Feb 23, 2008)

You can also calculate runtime for any light that you know the information for.

Great site, prevents me from breaking out the calculator for many of the math stuff I have to do.

Thanks!


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## Handlobraesing (Feb 24, 2008)

penquissciguy said:


> I've been on school vacation this week and decided it might be fun to tinker with some javascript programming. I like the LED Pro program for calculating runtimes, but I usually am on either a Mac or a Linux machine. So, I wrote a little javascript page that does the same thing as the runtime part of LED Pro. You can find it here. I hope someone can make good use of it.
> 
> Ken



It would give a lot better estimate if you include a derating factor based on mAh capacity vs. mA for each chemistry.

Battery's mAh rating method is significantly different between chemistries.

NiMH is usually 0.2C, SLA 0.05C and alkaline at 25mA. 
The actual mAh is significantly affected by mA and SLA and alkaline are affected to the point that without derating factor, the result is useless.

AA alkaline is rated at 2850mAh at 25mA, but only 1400mAh at 500 mA.


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## penquissciguy (Feb 24, 2008)

Handlobraesing said:


> It would give a lot better estimate if you include a derating factor based on mAh capacity vs. mA for each chemistry.
> 
> Battery's mAh rating method is significantly different between chemistries.
> 
> ...



I was thinking about that when I was writing the program. I may add a box for indicating battery chemistry if I can find derating values for the various chemistries. 

Ken


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## penquissciguy (Jul 17, 2008)

I moved the calculator page to my new hosting. The link in the first post and in my signature have been changed to the new address.

Ken


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## Illum (Jul 17, 2008)

the LED-Pro originated as a stand alone program that can be downloaded onto your computer and ran independently from the internet
the program is saved on http://www.jtice.com/led_pro/led_pro.htm
its a freeware AFAIK, As I have a copy on my workstation

It was developed by user jtice, rothrandir, et al...theres a thread on this, I insist it:thinking:

EDIT: found the thread [09-23-2003] *Introducing the LED Pro Modders Program
*


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## KeyGrip (Jul 17, 2008)

That is really excellent. This will help greatly when I start my mods. Apparently two AW Li-Ion C cells will drive an SSC P7 with a Vf of 3.5v for six hours and twenty minutes given 80% converter efficiancy. This is really fun.


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## penquissciguy (Jul 17, 2008)

Illum_the_nation said:


> the LED-Pro originated as a stand alone program that can be downloaded onto your computer and ran independently from the internet
> the program is saved on http://www.jtice.com/led_pro/led_pro.htm
> its a freeware AFAIK, As I have a copy on my workstation
> 
> ...



Yes, LED Pro was my inspiration for making the web page. It's a good program, but I don't run Windows, so LED Pro is not useful to me. Since my little script runs in just about any web browser, anyone on any platform can use it.:thumbsup:

If you don't want to get online to use the calculator, you can also save the web page to your hard drive and open it from there. It works just fine that way.

Ken


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