How NOT to connect a Potentiometer (What's inside and how did it blow)

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This video was inspired by a mistake I had made when installing a 10k ohm potentiometer that was supposed to serve as a voltage divider before feeding into my 0-50v to 4-20ma voltage transducer. This division was made necessary due to the fact that the battery voltage on the 48 volt system can reach voltages up to 64 volts during an equalize cycle on Flooded Lead Acid batteries, which would be outside of the acceptable input range. Since there is already scaling happening inside of the PLC, all I need to do is adjust the scaling by the amount of the voltage transducer plus the amount of scaling caused by the voltage divider.
It took me quite a while to figure out the whole idea of using a pot as a voltage divider. I had always thought that voltage dividers needed to be made up of multiple resistors with carefully selected values - until a partner of mine whom is an electrical engineer had suggested to pick up a handfull of pots. I stopped by Fry's electronics in Fremont, CA and picked up the only wire wound pot they had. Unfortunately Frys carries less and less of these parts that hobbyists like myself need for projects like this...I was looking for a few different resistance values and only could find the one they had. I will be going to amazon for the purchase of my next one.
It was a pretty cool video and a fun experience taking this device apart. I knew it was wire wound, but in my mind to have a single wire that in a package no more than 3/4" x 3/4" equated to 10,000 ohms of resistance seemed insane to me. Based on what I learned and showed in this video is very much is possible and quite the engineering accomplishment. The strand of wire had an insane amount of tensile strength, in fact I struggled to try and pull it to the point where it would snap. It is very very very fine, much smaller than a human hair.
One of the questions that I still have is how exactly the wiper moves up and down across the different layers of windings. I was not able to figure this part out.

[@Sparky4Life913]

Good choice of meter, I too have the 117, with the magnetic strap for hanging, love it! Great info 👍🏻

[@tumblevids]

same happened with my potentiometer. I mean some fumes came out but reading in multimeter is coming correctly for both sides how?

[@catprog]

Could you have put a resistor on the wiper lead and connect the positive to the other side to make a voltage divider?

[@HighTechLab]

Voltage divider needs negative reference. Variable resistor, yes. The voltage would vary based on load. While the transducer should be a constant load, it can still float and cause inaccurate reading.

[@henryhenry3832]

If you look at the diagram on the potentiometer it shows that number 2 is the end one.

[@infotech4990]

Noooooooo! You voided the warranty by opening it up!

[@Stoner916sac]

Why on earth are you still worrying about using that expensive plc junk? Just use a micro controller....like a pi or the hundreds of others. you can suit it to your particular needs rather than trying to adapt this commercial crap to your needs and if it dies the diy way wont cost you a fortune

[@MarkFunderburk]

Because a micro on its own doesn't have the proper I/O

[@diamondev1]

Pretty sure he needs something that can stand high voltage capabilities

[@thecow2756]

@@diamondev1 and high amperage

[@tfinnm]

plus its kinda cooler to have...

[@diamondev1]

@@tfinnm I mean he can use microcontrollers with maybe relays I suppose

[@billybbson8838]

what 0 views

[@billybbson8838]

youtube has finally done its job

[@HighTechLab]

Sounds like you are first. Well done