L.E.D. Conversion
Thread Starter
Instructor
Joined: Jun 2004
Posts: 203
Likes: 0
From: CA
L.E.D. Conversion
First off, I've tried the search function and found little to no info avail.
I've seen all the post regarding changing the interior lights to LED. But i'm no electronics guru. I've done the conversion but am not satisfied with the brightness. Does anyone know what resistor to use to get the brightest light poss for the door controls and other related lights. I'm almost ready to go back to standard bulbs
. TIA
I've seen all the post regarding changing the interior lights to LED. But i'm no electronics guru. I've done the conversion but am not satisfied with the brightness. Does anyone know what resistor to use to get the brightest light poss for the door controls and other related lights. I'm almost ready to go back to standard bulbs
. TIA
Burning Brakes
Joined: Oct 2003
Posts: 877
Likes: 0
From: Kansas City
If you can give me some more info I could figure something out for you. Basically the more juice you have running through them the brighter they will be.
Problems can be how big the wire is, what the source is capable of putting out, and how much current the diodes can take. Do you have a part number?
I also need to know what all is plugged up in this little makeshift circuit.
Problems can be how big the wire is, what the source is capable of putting out, and how much current the diodes can take. Do you have a part number?
I also need to know what all is plugged up in this little makeshift circuit.
Drifting
Joined: Sep 2004
Posts: 1,961
Likes: 2
From: Fort Knox
Leds
Hey this chart ive found helped me a many time. here is the link :
http://www.7volts.com/led_resistor.htm
snoopdan
http://www.7volts.com/led_resistor.htm
snoopdan
Le Mans Master
Joined: Jan 2001
Posts: 5,008
Likes: 508
From: Hilton NY
Most leds can carry 20 ma maximum continuous; some leds such as Lumileds will go over 70 ma, check the internet for exact led characteristics. To select a dropping resistor for 20 ma at 14.7 volts which is a common led maximum and car voltage maximum, wire a 1k or higher potentiometer in series with the led, ammeter and 14.7 volt power supply. Make shure the potentiometer is set for maximum resistance. Turn down the potentiometer until the ammeter reads 20 ma then disconnect the potentiometer and measure it's resistance. Choose a resistor that is equal to or higher than the measured value; if the potentiometer read 580 ohms and you had a choice of 576 ohms or 590 ohms, pick the 590 ohm resistor so the current wouldn't exceed the 20 ma. Allied Electronics and Digi-key have online catalogs of both resistors and leds; for example, Vishay brand 1/4 watt 1% metal film resistors cost 20 cents each. In comparison, Radio Shack has few choices on resistor values. You can use as little as 30 gage wire per led.
Burning Brakes
Joined: Oct 2003
Posts: 877
Likes: 0
From: Kansas City
Originally Posted by Fast one
Most leds can carry 20 ma maximum continuous; some leds such as Lumileds will go over 70 ma, check the internet for exact led characteristics. To select a dropping resistor for 20 ma at 14.7 volts which is a common led maximum and car voltage maximum, wire a 1k or higher potentiometer in series with the led, ammeter and 14.7 volt power supply. Make shure the potentiometer is set for maximum resistance. Turn down the potentiometer until the ammeter reads 20 ma then disconnect the potentiometer and measure it's resistance. Choose a resistor that is equal to or higher than the measured value; if the potentiometer read 580 ohms and you had a choice of 576 ohms or 590 ohms, pick the 590 ohm resistor so the current wouldn't exceed the 20 ma. Allied Electronics and Digi-key have online catalogs of both resistors and leds; for example, Vishay brand 1/4 watt 1% metal film resistors cost 20 cents each. In comparison, Radio Shack has few choices on resistor values. You can use as little as 30 gage wire per led.
This is really good advice. Becareful though. Depending on the characteristics of the LED you might be running it with too much current. It's really important not to send too much current throught his bad boy cause it could catch on fire. BTW most LEDs have around a .7 volt turn voltage. This means that until .7 volts are across the LED you won't see any current flow and no lights from the LED. I'm not sure if that will help you but you might help you.
It's also important to keep in mind that just because you can run 90mA of current, that doesn't make it always a good idea. You could have lots of complications. One that really sticks out with me is temperature. The resistivity of your resistor will change slightly with temperature so you might want to give it a little bit of error.
Goodluck.
