Observe: Drawing and Interpreting Circuit Diagrams 

Circuit diagrams are very helpful when we design circuits.


A circuit diagram explains various electrical parts using standard circuit symbols. A circuit symbol is a drawing that represents something in a circuit. Circuit symbols and diagrams make communication much easier between countries.
   Circuit Diagram

Chart of Circuit Symbols
Circuit Item What Does it Look Like? Circuit Symbol
Open Switch
A switch allows you to open or close a circuit (or part of a circuit) to control the flow of electricity.
            
Battery
A power source provides the energy for the circuit. 		 
Lamp
A lamp turns electrical energy into light. Because it uses electrical energy and lowers the current in a circuit, a lamp is a load. 		 
or 
Motor
A motor changes electrical energy into the energy of motion. Because it uses electrical energy and lowers the current in a circuit, a motor is a load.
            
Buzzer
A buzzer changes electrical energy into sound. Because it uses electrical energy and lowers the current in a circuit, a buzzer is a load. 		           
or
Resistor
A resistor is a circuit item used to control the amount of current in a circuit. Resistors work great on circuit boards because they take up very little space. Because they use electrical energy and reduce the current in a circuit, resistors are a load.
or                        

Drawing circuits with circuit symbols is easy.  Use the symbols for the circuit items you need; you can draw them directly on a piece of paper.  Then, connect the items with lines.  The lines on a circuit diagram represent wire.