rgb led strip

Forum 2005-2010 (read only) Hardware Development
1

hi,

i have 12V, 8A dc, 5m length rgb led strip. it has 30 leds per meter.

when i cut the strip so as to have 3 leds per each piece, what will be the power requirements for it ???

pls help me to solve this....

thanks in adv.....

2

I believe its the same type as the one I'm using.

Still use 12v

3

but if we give 12v per 3 leds, then power will be wasted ??

for 5m length strip we are using 12v and for 1m, 2m, 3m, etc. also we are using the same 12v. i think it may be the wasting of power. is n't it ???

4

nope, it will consume only 180ma max

5

if it consume 180ma then why we should apply 12v dc.
don't feel that i m hesitating u...
pls tell me full details

6

tell me full details

It's a little think called ohms law, Voltage = current times resistance.

By cutting the LEDs strips you make the resistance higher because there are less LEDs in parallel. Therefore they take less current but still need the same voltage to drive the current through.

7

oh k thanku very much....

so 3led strip needs 12v dc but the current changes and this current may be 180ma per led. is it right...

8

Without knowing exactly what sort of LED strip you have that sounds right. Lets do some sums:-
12V, 8A dc, 5m length rgb led strip. it has 30 leds per meter.

30 * 5 = 150 LEDs
at 8A this is 8 / 150 = 53mA
So it should draw this much. In addition each RGB LED is actually 3 LEDs so that gives a current of 53 / 3 = 17.7 mA which sounds bob on for an LED (typically about 20mA each)

9

Better make sure you CAN cut it into 3-led segments, and exactly WHERE you can make those cuts. For a 12V strip, you probably have parallel combinations of serial circuits of 3 LEDs in each one, so in THEORY you're fine. But you need to cut so that you separate between the series circuits an not in the middle of them!

10

yes the strips are wired in groups of 3 leds so as long as you cut them on the cut lines (between the solder pads) you will feed it 12v for any length (the current it will use will change with the length but the voltage should stay the same.

For instructions on cutting RGB LED strip