1. Diode Foundations of Technology Diode © 2013 International Technology and Engineering Educators Association, STEM  Center for Teaching and Learning™ Foundations of Technology Teacher Resource Unit 4 Lesson 4

2. Objectives: 1.You will build a simple circuit to show that a diode allows electrical current to flow in one direction.

3. You will need the following parts from your kit: 1.Breadboard 2.220 ohms resistor (red, red, brown, gold) 3.Diode 4.LED (light emitting diode) 5.9 volt battery lead 6.9 volt battery cathode anode

4. Use this schematic to construct the experiment. anode cathode anode cathode + - 9 volts Quick Check: Your circuit should like this one. 220 ohm resistor

5. This circuit will light the LED. 1.If there is electrical current, then the LED will light up. 2.A diode is designed to restrict electrical flow to only one direction. 3.Diodes are used to keep electrons from getting places that might cause damage to an electrical circuit. 4.Diodes are often used in Logic Circuits in computers.

6. 1.Connect the 9 volt battery. 2.Observe the brightness of the LED. 3.Disconnect the 9 volt battery. 4.Now take the diode out and put it in backwards. 5.Reconnect the 9 volt battery. 6.Observe the brightness of the LED. Troubleshooting: 1.If the LED does not light up, check to make sure it is in correctly. 2.Check if the diode is in the right way. 3.Check the battery. Does it have voltage? 4.Are there any breaks in the circuit?

7. By completing this experiment, you should have seen that the LED will only light up when the diode is connected in the correct direction. This demonstrates that current will only flow in one direction when a diode is in a circuit. In complete sentences, write what you learned about a diode in a circuit.