# Potentiometer Question



## Bwells (Mar 30, 2014)

I have a handheld throttle that has a pot for speed adjustment. The knob is off at 7 oclock and rotates to the 5 oclock position. When turned it reaches max voltage at 11 oclock and stays that way up to the 5 oclock position. What I would like is to spread the voltage across the whole pot instead of just half. Upon searching, I find two kinds of pots, linear and audio taper. It seems for this application I would want an audio taper. Stamped into the back of the existing pot is B100KΩ so this is linear as A designates audio. Would a simple swap fix my problem? Forgot to mention that this is a DC throttle and also has memory, so I don't think the pot is actually controlling track voltage but a signal to the base unit, not sure.
Hopefully this is enough info to start with. I'm all ears!


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## wvgca (Jan 21, 2013)

depends on how the pot is wired in ,, for an increasing situation .. a linear pot would go from 0 to appx 40k in that rotation .replace with a 40k linear ...
for decreasing, it would go from 100k to 60k at 11 o'clock position ... replace with a 40k pot _and_ an inline 60k resistor ..
that would give you close to 'full range' operational rotation ..
replacing with a logarithmic taper or audio pot of same value [100k] would help in an increasing application, worsen in a decreasing application .. ie half rotation position is appx 10% of resistance value
:


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## Bwells (Mar 30, 2014)

Thanks wvgca, I may be looking at something that is over my head. I think I understand changing to a 40K, Radio Shack has a 50K that should do so I'll give it a try. I can always go back to the 100K and be happy with what I have. That third leg is killing me, I keep thinking about a rheostat so I need to learn more about pots.


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## cid (Jul 3, 2014)

Hey Bwells, don't forget to add that 50k resistor to keep the circuit nominal, probably on the +leg of the pot but that really depends on the circuit. Were I doing this I would use some of those Rad Shack clip-on jumper wires (pack of 6?) to connect the new components and test. Should work just like wvgca says...


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## johnfl68 (Feb 1, 2015)

Bwells:

This page may be some help to learn more:

http://sound.westhost.com/pots.htm

It covers some aspects that more than you need, but is a good place to get a general overview.


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