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?
marry roser
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.
Debasis Parida
Joined August 22, 2019 125Thursday at 12:29 PM
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.