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  1. #1
    my dog's Frisbee launcher
    Reputation: befoot's Avatar
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    18volt to 14volt step down?

    Hi guys, I have an old 12volt Night Sun and I'm build a 14volt LED light.(Achesalot's - fantastic light)

    the thing is I work construction and I have lots of 18 Volt batteries and chargers on hand. So I was wondering if I can step down a 18volt battery to 14volts or should I just cough up the cash for new 14volt batteries and a charger? If this can be done...tips or links anyone?

    BTW...I was planing on Overvolting the 12 volt Night Sun at 14 volts

    thanks, Billy
    Darwin was an Optimist

  2. #2
    ...a wiggle theres a way
    Reputation: wiggy's Avatar
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    There are a few ways you can do this
    you could get a step down transformer that would take 18in and put ~14volts out

    you could also do it with a pot

    or you could simply use resistors and make it drop that way just make sure that you get the proper wattage depending on how many amps your application is going to be drawing that way you don't burn them(resistors) out

    They do have voltage regulators but to my knowledge they do not have any 14vdc ones (if i am incorrect someone let me know) they have 5vd, 12vdc, and a handful of others

    if it was me i would go the transformer route if your settled on using an 18volt pack other wise just get a 14volt one because it maybe easier than having to fabricate a board

    good luck

    joe

  3. #3
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    A buck converter like the bflex from Taskled.com will do the job perfectly and give you a whole rack of functions to the light. Most importantly it will regulate the current to the led's ensuring a consistant brightness (you set the level), it will also allow multiple brightness levels, temperature regulation, strobe + much more

    Hope this helps

    Ian

  4. #4
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    Sorry, my old response did not make sense!

    Use a buck converter!

  5. #5
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    Reputation: Walt Dizzy's Avatar
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    Driver?

    Quote Originally Posted by befoot
    Hi guys, I have an old 12volt Night Sun and I'm build a 14volt LED light.(Achesalot's - fantastic light)

    the thing is I work construction and I have lots of 18 Volt batteries and chargers on hand. So I was wondering if I can step down a 18volt battery to 14volts or should I just cough up the cash for new 14volt batteries and a charger? If this can be done...tips or links anyone?

    BTW...I was planing on Overvolting the 12 volt Night Sun at 14 volts

    thanks, Billy
    If you use the Buck Puck DC-DC voltage converter, it will take up to 32V and give you the correct output amps and voltage:

    http://www.ledsupply.com/buckpuck.ph...FQNisgodPx1pNA

    The bFlex takes up to 20 V input:

    http://www.taskled.com/bflex.html

    Deal Extreme offers a cheap driver, but I think the input is limited to about 6 volts:

    http://www.dealextreme.com/details.dx/sku.7612

    Sandwich Shoppe's offerings won't take input above 12 V:

    http://theledguy.chainreactionweb.co...roducts_id=394

    A driver is the way to go for LEDs because they are difficult to run well using a resistor. The current draw of an LED changes sharply with very small voltage changes. Plus putting a resistor in line with the LED wastes some of the battery energy.

    Note that Sandwich Shoppe, LEDSupply, and TaskLED offer boost converters too. That would make a 12V battery run a 14 volt string of LEDs. But boost converters are more delicate and may require heat sinking. Or they may not offer enough power output. Maybe not impossible, but more difficult.

    Walt

  6. #6
    my dog's Frisbee launcher
    Reputation: befoot's Avatar
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    Quote Originally Posted by iggs
    A buck converter like the bflex from Taskled.com will do the job perfectly and give you a whole rack of functions to the light. Most importantly it will regulate the current to the led's ensuring a consistant brightness (you set the level), it will also allow multiple brightness levels, temperature regulation, strobe + much more

    Hope this helps

    Ian

    In the LED system, I'm using a BuckPuck "3023-D-N-1000 Wired, 1000mA Output, DC Powered" from ledsupply.com
    so looks like I'm good go to go.

    Walt...thanks for all the info and links big help.

    I think I will just retire the 12volt Night Sun
    and make a 2nd LED light for the bars
    more light and longer run times.


    thanks...you guys just save me a bunch of cash on batteries
    Last edited by befoot; 12-21-2007 at 11:59 AM.
    Darwin was an Optimist

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