Variable resistors

John's picture

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Joined: May 08, 2020

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Variable resistors
May 8, 2020 - 12:10am

I have a schematic for a basic timer that I would like to build. Within the schematic, there is a symbol for a variable resistor. I believe it is showing only 2 connections to the rest of the circuit.

All of the variable resistors that I find for sale are shown with 3 terminals. What am I missing here?

Debasis Parida's picture

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Joined: Aug 22, 2019

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Use like this
May 9, 2020 - 10:46pm

Hi John, when you are using a potetiometer as variable resistor then you should use the variable pin and any one of the fixed end pin of POT.Leave the rest pin as No connection.Like wise there is only 2 wires will be used.

marry roser's picture

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Joined: Nov 21, 2019

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A variable resistor is a
May 14, 2020 - 12:52pm

A variable resistor is a resistor of which the electric resistance value can be adjusted. A variable resistor is in essence an electro-mechanical transducer and normally works by sliding a contact  over a resistive element. When a variable resistor is used as a potential divider by using 3 terminals it is called a potentiometer. When only two terminals are used, it functions as a variable resistance and is called a rheostat. Electronically controlled variable resistors exist, which can be controlled electronically instead of by mechanical action. These resistors are called digital potentiometers.

 

jaksonlee's picture

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Joined: Nov 07, 2019

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A variable resistor is a
July 16, 2020 - 5:42pm

A variable resistor is a resistor of which the electric resistance value can be adjusted. A variable resistor is in essence an electro-mechanical transducer and normally works by sliding a contact over a resistive element.