Well, do you know why power buttons use a symbol that looks ... meant to convey that a switch or button was in charge of ...

A circuit has to have a power source and that is often a cell ... the + and – symbols but they can be helpful. The switch symbol (off) has a line at an angle to show the circuit has a opening ...

First we need power, man – this symbol here is a cell ... we’ll set it up so if someone treads on it, the switch will close, setting off our alarm! Practise drawing the following series ...