Lecture 11: An Electrical Oddity

1. Lecture 11: An Electrical Oddity Electrical, Computer, and Systems Engineering Off the Beaten Path? Introduction to Engineering Electronics K. A. Connor

2. Career Planning and Educational Context • Find a few technical topics of interest and/or applications that you can return to over and over to provide context for your coursework. Try to find something that connects well with your personal interests. • Find a few job titles/descriptions that you can use over and over to provide context for your course selections Introduction to Engineering Electronics K. A. Connor

3. Career Information: Highlights of EDW Presentations in the Fall • General Info on EE, CSE and EPE http://hibp.ecse.rpi.edu/~connor/EDW-ECSE.ppt • Info from Prof. Radke on Imaging • Info from Prof. Degeneff on Power • Info from James Manchester on jobs at Tellium • Also check my web page http://www.rpi.edu/~connor Introduction to Engineering Electronics K. A. Connor

4. Example Job Description: EE • Candidate will participate in the design of analog, digital, and power circuits, instrumentation, video, navigation, sonar, electro-hydraulic control systems, embedded controllers, Printed Circuit Board design, computer, network, fiber optic communications, and cable & harness design for underwater vehicle systems in a design team environment. Candidate will also support the drafting, fabrication, test, and evaluation of prototype and production hardware. • Candidate required to be familiar with C++, Matlab & PSpice simulation tools, and OrCad & AutoCAD documentation tools. Candidate required to be familiar with printed circuit board (PCB) design process. Candidate must be capable of operating standard office software packages. Candidate required to be familiar with operation of Oscilloscopes, DMMS, network analyzers, spectrum analyzers, and other test & measurement equipment. Introduction to Engineering Electronics K. A. Connor

5. Technical & Personal Interests: Examples • Music • Recording: Signal compression • Instruments: MIDI or specific instruments • Listening: Audio electronics • History • Electrical science: Telephony, broadcasting • Businesses: GE, IBM, Intel, Microsoft, Palm • Military: Weapons, intelligence • Sports • Playing: Organizing software (team sport) or controls and feedback (auto racing) • Watching: Image processing • Training: Equipment Introduction to Engineering Electronics K. A. Connor

6. An Example of an Application That Can Tie Together Your Education • Involves material from many different courses • Involves many types of career choices • Historically relevant for technology • Historically relevant for international politics • Involves music Introduction to Engineering Electronics K. A. Connor

7. 2 Minute QuizIdentify the Following MusicSome Links Are A Little Slow • Green Hornet • Summertime • Lost in Space • The Swan • Good Vibrations • Day the Earth Stood Still • Smoke Gets In Your Eyes • My Favorite Martian • Dark Shadows • 1 • 2 • 3 • 4 • 5 • 6 • 7, 7(alt) • 8 • 9 Introduction to Engineering Electronics K. A. Connor

8. The Theremin • The theremin was invented in 1919 by a Russian physicist named Lev Termen (his name was later changed to Leon Theremin). • Besides looking like no other instrument, the theremin is unique in that it is played without being touched. Two antennas protrude from the theremin – one controlling pitch, and the other controlling volume. As a hand approaches the vertical antenna, the pitch gets higher. Approaching the horizontal antenna makes the volume softer. Because there is no physical contact with the instrument, playing the theremin requires precise skill and perfect pitch. Clara Rockmore (1911-1998) Introduction to Engineering Electronics K. A. Connor

9. The Theremin: Music • Nosebleeds by CHINESEBURN • You Only Live Twice by Project Pimento • 3001 by Rita Lee • Latin Soul by the Manatees The Manatees Jan Vollaard Pamelia Kurstin Introduction to Engineering Electronics K. A. Connor

10. Sources of Theremin Music • http://www.geocities.com/Vienna/1859/music.html • http://www.electrotheremin.com/sounds.html • http://www.thereminworld.com/bands.asp • http://www.thereminvox.com/directory/66/ • http://www.teleura.com/shop/productview/7/3/ • http://woub.org/sync/feature-theremin.html (contains a lesson from Pamelia Kurstin) • http://www.atelier-theremin.com/mp3.html Introduction to Engineering Electronics K. A. Connor

11. Understanding the Theremin • Principles of AM: Amplitude Modulation • Capacitance • Tank Circuits • Oscillators • Schematics and Components • Related Devices Introduction to Engineering Electronics K. A. Connor

12. AM: Amplitude Modulation • Signal • Carrier • Product Introduction to Engineering Electronics K. A. Connor

13. AM: Amplitude Modulation • Square Law Amplitude Modulator Introduction to Engineering Electronics K. A. Connor

14. AM: Amplitude Modulation • Envelope Detector (AM Demodulator) Introduction to Engineering Electronics K. A. Connor

15. AM: Amplitude Modulation • AM Radio Receiver Introduction to Engineering Electronics K. A. Connor

16. Difference Frequencies • First Signal • Second Signal • Difference Signal • AM technique can be used to produce a low frequency signal that is the difference between two high frequency signals Introduction to Engineering Electronics K. A. Connor

17. Theremin: How It Works • The Player’s Hand Adds an Additional Capacitance to the Antenna Impedance Introduction to Engineering Electronics K. A. Connor

18. Theremin: How It Works • Pitch & Volume Control Using Oscillators Introduction to Engineering Electronics K. A. Connor

19. Theremin: How It Works • Fixed pitch oscillator frequency is compared to the frequency of the variable pitch oscillator. • The difference is in the audio range 0-3kHz. • Audio signal is amplified • Volume control works in a similar manner. Introduction to Engineering Electronics K. A. Connor

20. Theremin: How It Works • Zero beat oscillator circuit results is very low frequencies • Volume is also controlled by providing some additional capacitance from the player • Voltage controlled amplifier (VCO) is tool Theremin did not have Introduction to Engineering Electronics K. A. Connor

21. Theremin: How It Works • Schematic of Etherwave Theremin Introduction to Engineering Electronics K. A. Connor

22. Theremin: How It Works • LM13600 – National Dual Operational Transconductance Amplifiers with Linearizing Diodes and Buffers Introduction to Engineering Electronics K. A. Connor

23. Theremin: How It Works • Note, for the tank circuit • The remainder of the circuit reduces this frequency slightly Introduction to Engineering Electronics K. A. Connor

24. Theremin: How It Works • Diodes rectify the 14V AC input voltage from the wall wart • LM78L12 National Instruments 3 Terminal Voltage Regulator produces clean 12 volt power Introduction to Engineering Electronics K. A. Connor

25. Theremin: How It Works • DC Voltage to Voltage Regulator I I Introduction to Engineering Electronics K. A. Connor

26. Are There Some Devices Based on Similar Ideas? • Metal Detector: The coupling between coils is affected by the proximity of metal, either magnetic or just conducting. Introduction to Engineering Electronics K. A. Connor

27. What Ever Happened to Leon Theremin? • Theremin: An Electronic Odyssey • Leon Theremin was the secret link between sci-fi films, the Beach Boys, and Carnegie Hall. His self-named electronic musical instrument--the first of its kind--took the world by storm in the 1920s and '30s. Theremin: An Electronic Odyssey , winner of Sundance's Filmmakers Trophy, explores the inventor's strange life and times, including his mysterious 50-year disappearance beginning in the 1940s. Interviews with theremin virtuoso Clara Rockmore, synthesizer pioneer Robert Moog, and Theremin's contemporaries, as well as clips from movies such as The Day the Earth Stood Still, featuring the unworldly sounds of his creation, show an eccentric genius working toward success until his sudden vanishing in the Soviet Union. Footage of Theremin at 94 years old, finally rediscovered and rewarded for his achievements, brings a celebratory ending to what could be a grim or at least uncertain story, but instead is a fascinating documentary. Introduction to Engineering Electronics K. A. Connor

28. Theremin Information • Moog Music: http://www.moogmusic.com • Theremin Info: http://theremin.info/index2.shtml • ThereminWorld: http://www.thereminworld.com/default.asp Introduction to Engineering Electronics K. A. Connor

29. Where Will You Encounter This Information Again? • ECSE-4520 Communications Systems: Modulation, Demodulation Fundamentals • ECSE-4060 Communications Circuits: Detectors, Mixers, Modulators, Demodulators • ECSE-2100 Fields and Waves I: Inductance, Capacitance, Transformers Introduction to Engineering Electronics K. A. Connor

30. Parting Words • From the Day the Earth Stood Still Introduction to Engineering Electronics K. A. Connor

31. Acoustics Terminology • Bandwidth: The bandwidth is related to the amount of information which a given channel may transmit. For the human ear, bandwidth is 20-20kHz • Wavelength: Speed of sound divided by frequency • Carrier: In an AM or FM system, the oscillator or signal which is being modulated by the program or modulating oscillator or signal. Source: Zen Audio Project http://www.sfu.ca/sca/Manuals/ZAAPf/i/index.html Introduction to Engineering Electronics K. A. Connor