[SOLVED] Resistor Identification Help Needed

Thread Starter

martyparish

Joined Aug 21, 2022
3
Hey first post here! And it's a noob question but I really would like someone to help confirm this resistor's value.

I'm working on an automotive spot welder that was "stuck on high". We figured the potentiometer was bad. It the process of gaining access to the POT, we broke it (pulled the whole shaft out trying to get the knob off), so I couldn't confirm it was bad or not.

While prepping to install the new pot, I accidentally broke a resistor that was soldered directly to the center terminal of the pot.

I'm not sure about what color the third band is?? Either gold or orange?

It's a 2.5K pot if that helps. Pictures attached. Thanks for any help!!
 

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MrChips

Joined Oct 2, 2009
27,141
Welcome to AAC!

Resistor color code looks like RED-PURPLE-BROWN-SILVER which is 270Ω ±10% 1W.
The potentiometer is 2.5kΩ. Wattage and linear or log taper is unknown.
 

sagor

Joined Mar 10, 2019
756
Third band may be orange, making it a 27k resistor. Hard to tell in the photo and if the colors faded.
Green (?) band indicated 0.5% tolerance, though I find it hard to believe that a resistor that appears to be a carbon composition has a 0.5% tolerance. Could be silver but again hard to tell by photo.
That all said, if the resistor is soldered to the pot wiper (0 to 2.5k), not likely the broken resistor would be 27k. Most likely a lower value.
 

Thread Starter

martyparish

Joined Aug 21, 2022
3
Thank you both for the input! I took the resistor out in the natural light and the third band definitely looks brown.

sagor, thanks for that extra input on the "likely" value that would be used in that application.

The .5 tolerance is weird! And it really looks like it's green and not faded??

I have ordered a 270 ohm carbon comp with 5% tolerance. Hope it works out!
 

DickCappels

Joined Aug 21, 2008
9,320
There are a three two orders of magnitude between 270 and 27,000. If in doubt you should be able to measure the large piece by probing the wire lead and the carbon mixture exposed at the other end.

Edit: Corrected order of magnitude.
 
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Thread Starter

martyparish

Joined Aug 21, 2022
3
Just wanted to follow up to all of you kind folks who helped.

I followed DickCappels advice and measured the longer broken piece that was leftover. Only a small portion of the other end broke off.

It measured 270 ohm. I had already ordered a 270 so that worked out.

I've soldered it in and put the welder back together and it is alive!

Thanks to everyone! Especially Sagor and DickCappels!


Marty
 
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