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Author Topic: how to setup a potentiometer  (Read 3638 times)

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Offline beginner435Topic starter

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how to setup a potentiometer
« on: July 31, 2007, 07:15:50 PM »
I would like to know how potentiometers work. there are more pins than i can deal with

Offline sdk32285

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Re: how to setup a potentiometer
« Reply #1 on: July 31, 2007, 09:51:23 PM »
There are usually three pins. the two on the end are like a normal resistor. The middle pin is called a wiper. As the pot is adjusted the amount of resistance between a single end and the wiper changes (note: the resistance from one end to the other end should remain constant).

When your using a pot and need to send a signal out to something (ie. a micro) you can put a voltage across the outer terminals and read the voltage from the wiper as an analog signal (this setup forms a voltage divider).
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Offline Gertlex

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Re: how to setup a potentiometer
« Reply #2 on: August 01, 2007, 11:05:01 AM »
Here's a very helpful guide that shows pictures of what a pot looks like inside:
http://www.geofex.com/Article_Folders/potsecrets/potscret.htm

It'll give you a good idea of how they work, just by looking at them.

The don't all look like that though.  The ones I bought recently look like this:
http://www-personal.umich.edu/%7Eerelson/PotDis01.png

(When you burn the one i have, it looks like this: http://www-personal.umich.edu/%7Eerelson/PotDis02.png ;D)
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Offline Hal9000

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Re: how to setup a potentiometer
« Reply #3 on: August 02, 2007, 07:00:24 AM »
You can also get really small trimpot things that are only very small and have all the innards sort of exposed. ideal for low cost apps and where the user doesnt have to adjust the pot all the time.
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Offline Gertlex

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Re: how to setup a potentiometer
« Reply #4 on: August 02, 2007, 11:54:54 AM »
You can also get really small trimpot things that are only very small and have all the innards sort of exposed. ideal for low cost apps and where the user doesnt have to adjust the pot all the time.

You can salvage those from old electronics (i.e. radios).  Be warned though, that if you're doing a high powered circuit (i.e. motor speed control) you'll need a pot/trimmer with high power rating.  You'll also probably need a heatsink.
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Offline HDL_CinC_Dragon

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Re: how to setup a potentiometer
« Reply #5 on: August 02, 2007, 01:55:35 PM »
I just pulled out a pot from some amplifier circuit I had made in an electronics class and using my DMM I found it goes from 0Ohms to 9,150Ohms...? That seems like a REALLY high amount of resistance from a pot... I tried to look up its specs but the only things written on it are "10KD" and "9526"
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Offline hazzer123

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Re: how to setup a potentiometer
« Reply #6 on: August 02, 2007, 02:22:21 PM »
Not at all  :)  Pots up to a max value of 470K are pretty common :)

http://www.maplin.co.uk/Module.aspx?TabID=1&ModuleNo=2205&doy=2m8
« Last Edit: August 02, 2007, 02:25:06 PM by hazzer123 »
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