Where do I find a driver that will let me run LED headlights, taillights etc off of a traction system with a pair of 12vdc batteries in series. They aren't big on amp/hours, so incandesents are no good.
2007-09-24 09:47:30 · 3 answers · asked by redscott77092 4 in Science & Mathematics ➔ Engineering
Why need a "driver"?
You can run LEDs directly on DC source BUT you need to limit the current, and that is done with a simple resistor in series with the LED.
So, you need to find out what is the "nominal forward current" of the LED you are using, and then calculate
Resistor (in Ohm) = 24 (Volt) div.by
Say your LED is rated at 30mA (means 0.03 Ampere)
then your resistor should be 800 Ohm / 1 Watt.
Do that for each LED separately.
2007-09-24 10:31:38 · answer #1 · answered by Marianna 6 · 1⤊ 0⤋
The standard solution is to use a series resistor, but in your case 90% of the power from the battery will go to heating the resistor and only 10% to illumination, a bad trade. A better way is to run as many LEDs as possible in series, that way the same current creates many more points of light. The catch is you need LEDs that all run on the same current, so you can't select different sizes. Standard red LEDs need 20 ma current at about 2 volts drop each. Use 14 in series should be about right.
2007-09-24 18:21:43 · answer #2 · answered by lare 7 · 1⤊ 0⤋
Maxm has something designed just for your application:
http://pdfserv.maxim-ic.com/en/ds/MAX16831.pdf
.
2007-09-24 17:04:11 · answer #3 · answered by tlbs101 7 · 0⤊ 0⤋