1. Capacitor Foundations of Technology Capacitor © 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 capacitor stores electrical energy. 2.You will be able to observe the LED get dimmer as the capacitor discharges.

3. Two basic types Ceramic disk Electrolytic Has positive and negative sides Farads – unit of measure (F) Microfarads(uF) and picofarads (pF)

4. You will need the following parts from your kit: 1.Breadboard 2.1000 ohms resistor (brown, black, red, gold) 3.330 ohms resistor (orange, orange, brown, gold) 4.1000uF capacitor 5.100uF capacitor 6.1 LED (light emitting diode) 7.9 volt battery lead 8.2 wires 9.9 volt battery

5. Use this schematic to construct the experiment. 1000 ohm + - Flow of current 9 volts Quick Check: Your circuit should like this one. 330 ohm +

6. This circuit will make a LED dim. 1.When electron flow is present, the LED will be bright. 2.Capacitors are able to store electrical energy. 3.The larger the capacitor the more energy it is able to store. 4.Electrons flow from the battery through the LED and resistors. 5.Electrons will charge the capacitor. 6.When the battery is removed, the energy stored in the capacitor will continue to light the LED until it has been discharged.

7. 1.Start with the 1000uF capacitor in place. 2.Connect the 9 volt battery. 3.Observe the brightness of the LED. 4.Disconnect the 9 volt battery. 5.Observe what happens to the LED. 6.Replace the 1000uF capacitor with the 100uF capacitor. 7.Reconnect and then disconnect the 9 volt battery 8.Observe what happens to the LED. Troubleshooting: 1.If the LED does not light up, check to make sure it is in correctly. 2.Check the battery. Does it have voltage? 3.Are there any breaks in the circuit? 4.Is the capacitor in the right way?

8. By completing this experiment, you should have noticed the light from the LED grew dimmer as the capacitor discharged when the battery was removed. In complete sentences, write what you learned about a capacitor in a circuit.