How to light up 6 led without resistor by using 12v motor powered by homemade pelton/water turbine?

Can 12v dc motor/dynamo lighy up 6 led? 

6 Answers

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  • Jim
    Lv 7
    2 months ago

    LED's have a small range of allowable voltage & current, too much and they instantly burn out!

    Look at your specs and make sure you do not exceed them!!!

  • 2 months ago

    You can put them in series, they'll light up,   but you'll still need a resistor to limit the current.  Otherwise they'll burn up instantly.

  • 2 months ago

    NO, MOTOR IS NOT A PROPER GENERATOR.  IT GENERATES VERY SMALL VOLTAGE, A 12V DC STANDARD MOTOR ( NOT THE ONE COMES FROM COMPUTER, THAT EVER GENERATES ANY VOLTAGE ), MIGHT PRODUCT ABOUT 3V TILL 5V DEPENDING ON HOW FAST THE MOTOR IS ROTATING. 

    WHITE LED LIGHTS UP BETWEEN 3V TILL 3.4V , TRY FIRST PARALLEL ONE LED TO THE MOTOR OUTPUT AND SPIN IT FAST, BE SURE THE CONNECTION POLARITY IS CORRECT, OTHERWISE LED WOULD NOT LIGHT UP.

    IF LIGHTS UP IN NORMAL BRIGHTNESS, PARALLEL ALL 6 LED THE SAME WAY SHALL DO !

    IF LED LIGHTS UP VERY BRIGHT OR EVEN BURNS AWAY, CORRECT THE CONNECTION BY PUTTING TWO LED IN SERIES TO MAKE A 6V LED CHAIN, THAT PREVENT LED BURNS DOWN DUE TO OVER POWER BY TOO HIGH VOLTAGE.

  • 2 months ago

    You can use a current source to drive the LEDs.

    The Vf of red LEDs is ~ 1.5V @ 15ma.

    6 of them will need ~ 9V.

    3V is plenty of overhead.

    Download a schematic for a current source and build it. I use an LM317 voltage regulator configured as a current source at ~ 15mA.

    You could use a zener diode in parallel with the string to prevent over driving them. The voltage depends on the color of the LEDs.

    Even if the generator is AC the LEDs will light during half of the cycle.

    Tell me what the MFG and Part # of the LEDs is and I can assist you in getting it to work.

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  • 2 months ago

    you need something to limit the current. If not a resistor, then an IC that limits the current.  LEDs are current operated devices, generators produce voltage.

    LEDs have a very steep voltage vs current curve and if the voltage gets a bit high, the current increases a lot. And, when they warm up due to the current, the voltage needed drops causing more current. Net result, they blow out.

    as to power levels, depends on the LEDs rating and on the current rating of the generator.  LEDs are as low at 10 mA and 2 volts, and as high as 100 mA at 4 volts. 

  • 2 months ago

    There should be plenty of power for the LEDs.  I have a flashlight with 5 LEDs powered by a 1.5 V AA battery.  But there is circuitry in the flashlight that I suspect contains resistors.  I doubt you can feed your 12 V power source directly to the LEDs with a resistor.

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