Potentiometers vs Resistors

[CET]

I'm still very much a padawan, and another saber smith I know just built a NB based saber and used a potentiometer to get different color options. I know nothing of potentiometers, but would like to know more.

I'm thinking that I'd like to modify my preferred dueling saber (also NB based) so that I can switch colors.

Is there any videos on the subject, or at least some good advice?

[FenixFire]

There is a thread on here that walks you through it. Basically a potentiometer and mosfet are needed for each die. I was thinking of trying it on the saber I just built, but the color worked out right on the first try, thanks to meeting one of the electrical engineers who used to work for CREE and a little resistor calculator he worked up for me.

[Silver Serpent]

A potentiometer is just a variable resistor. A simple example is a volume control knob. The typical use for them is when you're setting up a mixed color saber, and you want to "dial in" a specific shade. You place the potentiometer where the resistor would go, adjust it until you get the shade you like, and then measure its resistance. You then replace the potentiometer with a resistor matching that value.

If you want to have little knobs to adjust colors on the fly, be aware that potentiometers do go down to ZERO resistance at their lower end, so it can be possible to blow your LEDs if you turn it down all the way.

[NanoRex]

If you want to have little knobs to adjust colors on the fly, be aware that potentiometers do go down to ZERO resistance at their lower end, so it can be possible to blow your LEDs if you turn it down all the way.

You can always add another resistor in series to protect the LEDs so this isn't a problem.

[FenixFire]

Silver that is the theory the OP of the linked thread thought to, but the pots were not controlling the LEDs as initially thought. Instead used them to control the gates on a series of mosfets, basically creating his own pulse width modulator (LED driver). While retaining the blade effects of the NB. I did try it and it worked I just did not have room in the saber to fit it.
http://forums.thecustomsabershop.com...y+color+mixing

[Mineral]

I don't know much about this topic, but you might look into the difference between potentiometers and rheostats.

If I understand things correctly (and I frequently don't) a rheostat is a variable resistor that dumps excess signal to heat, while a potentiometer dumps excess signal to ground. That difference might be why a pot didn't work, but a rheostat might.

Electricians who actually understand this will correct me, I hope.