Connecting LED to 12V battery

[Laurynas]

I believe this should be easy.. Bud I have no Idea.
How can you connect LED to 12V battery? I heard that you have to use a diode and resistor, but how can you explain what is what?! Please I need details.

Thanks )

 

[grantr37]

current limiting resistor according to what the diode is rated for in mA and a polarity protector diode to save it from getting connected in reverse and frying/blowing..... a regulator IC should be useful as well...

 

[Laurynas]

current limiting resistor according to what the diode is rated for in mA and a polarity protector diode to save it from getting connected in reverse and frying/blowing..... a regulator IC should be useful as well...

I am using 5mm red LED

 

[telectrix]

LEDs require 2V. try a 1K resistor in series with the LED, measure the volts across the LED. if it's above 2.0V, increase the value of R. if below, decrease. make sure the polarity is right.

 

[Laurynas]

Ok. I still got one question.. Can someone explain me that diode thing.. How is it working? diode limits current too or something? Why they use diode in 12v battery and LED circuit?

 

[telectrix]

the diode is to protect the LED from reverse polarity.

 

[Kamikaze]

You could always use four 16000mcd LED’s and daisy chain them in series, you would not need a resister then. From memory the LED forward voltage is 3.4V to 3.7V, so a chain of four will drop in between 13.6V and 14.8V, which is safe for use on a 12V system. Just join the long leg to the short leg, long leg to short leg until you have a row of four. The +ve is the long leg end, -ve is the sort leg end. The disadvantage is that if any one of the LED’s blows, the other three in the row will blow too as they will be sinking more current. Oh by the way, if you do this I hope you like stadium lighting. :biggrin:

 

[Laurynas]

Gosh am I stupid or what.. I can't understand this simple s***...

 

[amlu]

you dont need to protect simple leds from reverse polarity. they simply refuse to light up, will be fine after you connect them right. leds are diodes too, Light-Emiting-Diodes.

 

[kenny james]

a 1k resistor will be fine

 

[Knobhead]

Click HERE

 

[telectrix]

nice one tony.

 

[Spoon]

Why dont you buy one that has a integral resistor. Problem solved.
L-53ID-12V - KINGBRIGHT - LED, 5MM, HE-RED | CPC

 

[telectrix]

too easy. got to blow a few LEDs first. it's called learning by mistakes.

 

[Spoon]

He could still wire it up the wrong way..

 

[Laurynas]

Basically, 470 ohm resistor has done its job.
I took information about 5mm red LED from data sheet, and then just calculated the resistance I needed. It was actually easier than i thought

Thanks guys

Tony - Your are real help!

 

[Geordie Spark]

Basically, 470 ohm resistor has done its job.
I took information about 5mm red LED from data sheet, and then just calculated the resistance I needed. It was actually easier than i thought

Thanks guys

Tony - Your are real help!

You're damn' right he is !!

Tony has more knowledge than you and I combined will ever hope to have !!