# Does it Matter Where I Place Resistors on Circuit for Lightsaber RBG LED

I'm trying to figure out the circuit of a Lightsaber I wish to assemble myself using an RBG LED (Tri-Cree RGB EP-X2) and am unsure where I can put the required resistors and also how many I need. I will be running the set up with 4 AAA alkaline batteries at 6V, and I would like to be able to customise the colour blending of the LEDs by changing the resistors that go to each individual diode. Do I need to place the resistor I wish to change the diode intensity with before or after the LED in my circuit? I'm sorry if this doesn't really make much sense, I'm still pretty new to this stuff so any help I can get would be fantastic. Thank you in advance.

• Hi; this sounds like you're not aware of the property that the current in a series of components is always the same. In that case, I'd strongly recommend getting a short introduction to electronics first – this is really basic stuff, and you'd have to come back for every little thing if you don't know it, which is very ineffective. Learning the basics now will save you a lot of time, I promise! Jan 27, 2021 at 14:51
• (1) You can place the series/current limiting resister before or after the LED, though I I think most people, me too, prefer to place the series resistor before the LED, because I think it better to think like, this: the resistor drops voltage from the voltage source, then goes to the LED. (2) Changing the series resistor value is one way to control the brightness of the LED, but a much better way is to use CCS (Constant Current Source) , (3) The following is a good basic course for electronics newbies: electronics-tutorials.ws. / to continue, ... Jan 27, 2021 at 15:17
• For Cree and other's power LED lamp, I would recommend this tutorial: (4) For Cree and other 1W LED (and CCS), I would recommend this: 1 Watt LED - Components 101: components101.com/diodes/1-watt-led. Jan 27, 2021 at 15:21