The device that creates a potential difference in an electric circuit is called a voltage source.

Here are some common examples of voltage sources:

* Batteries: Chemical reactions inside a battery generate a potential difference between its terminals.

* Generators: These use electromagnetic induction to produce a potential difference.

* Power supplies: These convert AC electricity to DC electricity with a specific voltage.

* Solar cells: These convert light energy into electrical energy, creating a potential difference.

The potential difference created by a voltage source is what drives the flow of electric current through a circuit.