Power LED module and finding the correct resistor...

Thread Starter

Ftwist

Joined May 14, 2019
2
Hello All,

I have what must be a very simple problem but I'm struggling to get my head around it.

I have these TruOpto OSPR6XW5-W4XZE1E1E White 6500K 6x1W Power LED 600lm and I am running each module of a 12v 3a DC power supply however I feel as though my working out is wrong while calculating the value of the resistor I need to use in the circuit for current limiting purposes.
So I am hoping you will be able to help me and show me where I am going wrong!

So...

R = (Vs - Vf) / If
Resistance = (Source Svoltage - Forward Voltage) / Current
Fill with info from the datasheet:

R = (12v - 10v) / 0.35
R = 5.7

Am I shooting in the right direction?
There is no mention of 'Forward Voltage' on the Datasheet so I have used the typical operating voltage.

Then I presume I have to work out a Power rating for the Resistor once I have the correct resistance value?

Thanks in advance for any advice.
 

ericgibbs

Joined Jan 29, 2010
18,767
hi Ftwist,
If this not homework, you may get the help you require, if I move the Thread to General Electronics Forum, please advise.?
E
 

djsfantasi

Joined Apr 11, 2010
9,156
Hello All,

I have what must be a very simple problem but I'm struggling to get my head around it.

I have these TruOpto OSPR6XW5-W4XZE1E1E White 6500K 6x1W Power LED 600lm and I am running each module of a 12v 3a DC power supply however I feel as though my working out is wrong while calculating the value of the resistor I need to use in the circuit for current limiting purposes.
So I am hoping you will be able to help me and show me where I am going wrong!

So...

R = (Vs - Vf) / If
Resistance = (Source Svoltage - Forward Voltage) / Current
Fill with info from the datasheet:

R = (12v - 10v) / 0.35
R = 5.7

Am I shooting in the right direction?
There is no mention of 'Forward Voltage' on the Datasheet so I have used the typical operating voltage.

Then I presume I have to work out a Power rating for the Resistor once I have the correct resistance value?

Thanks in advance for any advice.
Where did you get these values? Particularly If and Vf? I see you explained how you picked 10V for Vf, but why?

Re: power rating, yes, you do! How are you going to do that?
 
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