1. Electronic Signals & Semiconductors by Alec D, Fisher D, & Ethan L

2. Electronics and Electronic Signals Electronics are the use of energy to control, communicate, and process information. Electronic signals are what electronics are based on. An electronic signal is a varying electronic current that represents information.

3. Analog and Digital There are two types of electronic signals: Analog and Digital. Here is a good example to show the difference between analog and digital The kind of thermometer with the liquid that rises and lowers according to the temperature is analog. The type that just gives you a digital number is digital. In analog signals the electric current flows smoothly. In digital there are pulses of current that represent info instead of running smoothly.

4. Sound Recording (Analog) A record is an analog sound recording. There is a huge spiraling groove all the way around a record. The needle runs along the groove and moves back and forth in a certain pattern depending on the record. This back and forth motion creates an electric current which is fed into an amplifier and turned into sound.

5. Sound Recording (Digital) A CD is the different digital version of sound recordings (except for MP3 players). It contains microscopic holes called “pits” and the flat parts called “flats”. The pits are in a spiral formation just like the record grooves. The laser lens on the CD player reads/scans the discs flats and pits. The beam produces tiny flashes of light. The way the light flashes, due to how to grooves are ordered, creates a current that when fed into an amplifier and produces sound.

6. Semiconductors A semiconductor conducts but not as well as conductors. A semiconductor cannot conduct alone. It needs atoms from other elements to conduct. By controlling the number of atoms of the elements scientists can produce two types of semiconductor. They combine these two types of semiconductors in layers which creates the current needed to control electrical devices.

7. Solid-State Components: Diodes A solid-state component is part of a circuit in a signal is controlled by a solid material, such as a semiconductor. A diode is the semiconductor (mentioned in the last slide) that consists of the two types of semiconductors. A diode allows an electric current to flow in one direction only.

8. Alternating and Direct Current Direct Current flows in one direction only. A hand- held game would run on a direct current. An alternating current reverses direction over and over again. Your house is probably running with an alternating current. We just had to Mr. W... :)

9. Transistors When a layer of one type of semi-conductor is sandwiched between the other type of semi- conductor. A transistors can either amplify a current or switch a current on or off. When an electronic signal is sent it gradually grows weak which is the reason for a transistor. Transistors are also what make computers work.

10. Integrated Circuit An integrated circuit is smaller than a finger nail (0.5 cm square) yet contains hundreds of thousands of components. This tiny chip can power anything from video game consoles to space crafts. Hey! This is the same picture that's in the book! How cool is that? SO COOL!!!

11. Thank you for watching, we hope we didn't bore you, and we're sorry that we didn't provide popcorn, cookies, ice cream, or candy for you to eat while you watch. We were planning to bring all of these things, but it seemed Mr. W wouldn't like it very much. Yes Patrick, we hear your cry ;(