Quote:
Originally Posted by Laney760
I have just learned the word 'potentiometer' from Google. Thanks, nice word that. Does it meter the potential of something?
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I'd be the last person on here to try and persuade you MP3 was a better media than CD Ellie! As an apprentice, i worked on the 1st/2nd gen CD players before the system (as we know it now) was officially launched 33 years ago yesterday. As such i've got a soft spot for it.
Anyway - potentiometer - you've pretty much guessed it but not quite. Imagine a 12V battery, like in your car. Now imagine you have a 6v bulb you want to light. The 12v battery will blow it pretty quick. With a potentiometer you can "tap off" 6v for the bulb.
Now think of a bucket of water, lift it 12ft in the air and it has a 12 ft head of pressure courtesy of gravity for the water to flow out of it and water your plants. Trouble is, that will flood your plant pot, washing soil away from the roots and the plants can't absorb the water quickly enough so they die.
However, if the bucket is 6 ft in the air, it only has a 6 ft head of pressure to water the plants with which they can cope with, it will take 24 hours to drain so you can come back next day and refill it.
Now imagine a device that you can simply tap off the water level you need.
In more technical terms, the potentiometer is a potential divider where the potential is the voltage. It has 3 legs, one to connect to earth/0v, the other to connect to battery +ve/12v and the third to tap off the voltage you need - this is called the wiper.
It's usually a carbon track resistor and the wiper slides along it to enable the required voltage to be "metered" off the potential. This is why Bob was mentioning using a soft pencil to revive the carbon track to restore operation on a worn component.
I hope that all makes sense, i've tried to keep it simple while not insulting your intelligence, i hope i've succeded! For a more in-depth explanation, have a look at the Wiki page, it goes into more details abot the plethora of uses of potentiometers - you'll be amazed just how many you've got in one form or another!
https://en.wikipedia.org/wiki/Potentiometer