Scale output of Potentiometer

Thread Starter

adamj12b

Joined Mar 3, 2009
15
I have a potentiometer that has range of about 202 ohms. The range is about 982 to 1184 ohms. I need some way to scale the output of this to 0 to 5k ohms. Maybe somebody could give me an idea of how to go about doing this. I am not able to change out the pot either, as it is built into the application and non removable.

Thanks

-Adam
 

studiot

Joined Nov 9, 2007
4,998
Obviously this pot is part of a chain of resistors.
It could be a trim pot used as a variable resistor or an actual pot. What do you mean by 'output'?

Mik is right we need more information.
 

Thread Starter

adamj12b

Joined Mar 3, 2009
15
Hello. Sorry I was so vague. It was late and I was tired.

The potentiometer is on a drive by wire accelerator peddle that I purchased for an EV project. The peddle has 3 potentiometers in it. I will attach a picture of the small circuit board in the peddle.

Again, I am sorry for not being clearer. By output I meant resistance.

In the first picture I attached I filled in the measured resistance. In the second picture I showed the board as well as the wiper assembly. I hope this helps. If not just let me know.

-Adam
 

Attachments

Thread Starter

adamj12b

Joined Mar 3, 2009
15
I figured I might have confused someone by telling about the 3 pots in the peddle. I only need one of the 3 to work.

Pot 1 at the top of the pic, pin 2 for the wiper and 4 and 5 for the outputs.

Pot 2 in the middle of the pic, pin 3 is the wiper and 5 and 4 for the outputs.

Pot 3 at the bottom of the pic, pin 8 is the wiper and 5 and 6 for the outputs.

I hope this helps.

-Adam
 

Thread Starter

adamj12b

Joined Mar 3, 2009
15
Ok, I see how that picture could be tough. I created another pictorial of how the pot circuit lays out. So on one side of the pot is a 145 ohm resistor, on the other side a 206 ohm resistor and on the center pin there is a 788 ohm resistor. When the pot is turned, the resistance between the first pin and the center pin increases by 200 ohms. I need the resistance range of this pot to be 0 to 5000 ohms for my application. I hope this is easier to understand.

-Adam
 

Attachments

studiot

Joined Nov 9, 2007
4,998
I don't see how your circuit could generate the readings.

The resistance between terminals 1 and 2 must change in the opposite sense to the resistance between terminals 2 and 3 if your circuit is correct.
 

Dr Oetker

Joined May 21, 2009
5
Hi,

Your numbers don't match, but it is likely that you have some contact resistance on pot's moving part. Also, the min-max reading are mixed up, but nevertheless, I know what you need to achieve. While it is possible (and easy) to scale down pot's range it is not possible to scale i tup, with passives. Sorry, you will need to spend few $ for a 5k (4.7----5.6k) pot.
 
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