Pots as variable resistors

[almondcity]

Is it really as simple as wiring up the center lug and one of the outer lugs to the resistor pads?

 

[temol]

Exactly - you can use pins 1 and 2 (or 2 and 3). Here's the usual way of doing this

 

[fig]

If you measure Ω from pin 1 to 3, it will give you the total resistance of the pot regardless of the sweeper (knob) position. (just like a resistor). Measuring between 1-2, or 2-3, tell you the resistance based on the current sweeper position.

 

[Robert]

Yep.

Which outer lug depends on whether you want the resistance to increase or decrease as you turn the pot up. You'll also need to consider the taper (aside from linear) and how it is inversely affected when using lug 1 or 3.

It's also a common practice to connect the unused lug to the center lug, although not required and won't affect the behavior.

 

[fig]

In essence, this is what a trimmer is. When biasing using one, you are adjusting the resistance in or out of a transistor (or possibly another component or stage I suppose).
Once they are set you can measure as mentioned above, and replace the trimmer with a resistor of the same value.

Edit: Although I should note that anything I say in relation to electronics is subject to scrutiny.

 

[Feral Feline]

I've read that it's good practice to not leave a lug floating, that way if your pot ever goes south it'll still dump your signal forward — or something like that.