What toggle switch for multiple resistor selection??

[bluesdevil]

I'm new at this stuff so sorry if the question seems stupid, but I could use some advice from the more experienced. Basically I would like to know what kind of toggle (or rotary switch) I could use to route a single signal to 2 different resistor values and 1 straight without a resistor. Each of the 3 selections would go to the same end path. Would a "center off" DPDT toggle work?
    I figure out how to do the switching with only 2 path selections with a DPDT toggle, but want to switch between 3 signal paths.
             Thanks in advance to anyone who can help!!!

[RickL]

I think it can be done with a spdt centre-off switch. Input goes to centre of switch, one resistor from centre of switch to output (i.e. where ever you want the resistor or straight wire you choose to go to), second resistor goes from one outside terminal to output, other outside terminal goes to output.

In the centre position you get just that value of resistor, in the second position you get the two resistors in parallel (i.e. if both resistors are 10k you get a total resistance of 5k), in the third position the switch shorts out the centre resistor for the straight (no resistor) path.

Put the biggest resistor you want in the middle position and calculate the value of the second resistor to give the value you want when it's in parallel with the one in the middle position.

[bluesdevil]

Thanks Rick, I'll give it a shot and order up a SPDT switch when I get the rest of the parts for the project.  Just to make sure I got my parallel resistance formula right: the center resistor is going to be 10k, so I would parallel it with a 1.2k resistor to get 1k?
               Thanks again for taking the time to figure it out and explain so clearly.

[RickL]

Yup, that's the nearest standard resistor to get you (almost) 1k.