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Pot resistance

jrisebo

Nov 29, 2011
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I am looking to find out what the resistance of a Allen Bradley Pot is. The markings are 8466 Type J, and thats it. The schematic for the piece of equipment calls for a 8K resistor, but the Allen Bradley is a replacement, and it has a resistor between two of the posts. I am trying to find a Clarostat replcement to match the others that are in the piece of equipment. Hit me up for more info if you need it.
Thanks
Jim
 

Resqueline

Jul 31, 2009
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There has to be more markings somewhere, for example 1k, 5k, or 10k. You can also measure it if you have a DMM, and read the (color) codes of the resistor.
 

jrisebo

Nov 29, 2011
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There has to be more markings somewhere, for example 1k, 5k, or 10k. You can also measure it if you have a DMM, and read the (color) codes of the resistor.

Sorry, this is a potentiometer resistor, not a inline resistor with the color bands.
 

Resqueline

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it has a resistor between two of the posts
From that I interpreted that the A-B pot had a fixed resistor soldered between two of its three posts. Maybe it was a misinterpretation. Perhaps you could supply a picture?
 

jrisebo

Nov 29, 2011
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I will take a picture tonight. It does have a fixed resistor between two of the posts on the pot, but I dont even know what resistance the Pot is. Im a novice at electronics, just enough knowledge to fry something, lol. Doesnt help that this is from the 60's
 

Resqueline

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Ok, so I did interpret it correctly, and it was this fixed resistor (color) code I was asking about above (I just put it all in one line). Do you have a measuring instrument?
 

jrisebo

Nov 29, 2011
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Ok, so I did interpret it correctly, and it was this fixed resistor (color) code I was asking about above (I just put it all in one line). Do you have a measuring instrument?

Here are the pictures, I have measured the fixed resistor at 6K ohms, not sure if the color banding confirms. How do I know what the resistance of the POT is?
 

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jrisebo

Nov 29, 2011
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Here are the pictures, I have measured the fixed resistor at 6K ohms, not sure if the color banding confirms. How do I know what the resistance of the POT is?
By the color bands, someone else told me its a 39K resistor. Not sure why its even there, can you reduce a pot with a fixed resistor across?

I have ordered a 10K POT to replace this. The schematic calls for a 8K, do I need a 2K resistor across like this, or does it not really matter?
 

duke37

Jan 9, 2011
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10k in parallel with 39k equals 8k.
The value of the pot is normally marked around the edge.

Duke
 

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Like Duke says it does make sense with a 39k resistor in parallel with a 10k pot to make an 8k pot. If it really matters for the circuit, who knows..
It wasn't easy to see how it's connected though. Can you verify from my attachments if it's wired like I believe?
 

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jrisebo

Nov 29, 2011
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Like Duke says it does make sense with a 39k resistor in parallel with a 10k pot to make an 8k pot. If it really matters for the circuit, who knows..
It wasn't easy to see how it's connected though. Can you verify from my attachments if it's wired like I believe?

I will take a better pic tonight for you. Im gonna check tonight for any markings around the edge.
 

jrisebo

Nov 29, 2011
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Heres a better picture. It looks like its jumped between 1&2, and the resistor between 1&3. Not sure what that does.
 

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Resqueline

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Ok, then it's wired like in my little diagram. It becomes 0 ohms when turned fully CounterClockWise, and 8k ohms when turned fully ClockWise.
It seems you can use the 10k pot you ordered, and you can transfer the 39k resistor to this if you choose.
 

jrisebo

Nov 29, 2011
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Ok, then it's wired like in my little diagram. It becomes 0 ohms when turned fully CounterClockWise, and 8k ohms when turned fully ClockWise.
It seems you can use the 10k pot you ordered, and you can transfer the 39k resistor to this if you choose.
Cool, then that makes sense. its for a voltage power supply, so one way, 0 volts, the other way the max. Thanks for everyones help
 
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