* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download theremin - Courses
Control theory wikipedia , lookup
Power inverter wikipedia , lookup
Mathematics of radio engineering wikipedia , lookup
Control system wikipedia , lookup
Electronic engineering wikipedia , lookup
Alternating current wikipedia , lookup
Transmission line loudspeaker wikipedia , lookup
Spectral density wikipedia , lookup
Variable-frequency drive wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Chirp spectrum wikipedia , lookup
Power electronics wikipedia , lookup
Pulse-width modulation wikipedia , lookup
Mains electricity wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Regenerative circuit wikipedia , lookup
Opto-isolator wikipedia , lookup
Wien bridge oscillator wikipedia , lookup
Utility frequency wikipedia , lookup
Electronic musical instrument wikipedia , lookup
Superheterodyne receiver wikipedia , lookup
Theremi n THEREMIN Department of Electrical and Computer Engineering Theremin Background • Created by the Russian Inventor Leon Theremin in 1919. •First electronic instrument influencing Moog and pioneers in musical electronics. • The thereminist does not actually touch the theremin except to mute it. •Controlled by capacitance between hands to antennas. Placement of the hands relative to antennas controls pitch and volume. Theremi n Motivation Continuous Pitch: The theremin is a continuous pitch instrument like trombone or violin which makes staying in tune difficult. Also the lack of any physical reference makes playing difficult to learn. Continuous Volume: Staccato playing or quick stops and starts are difficult with the theremin because of continuous volume control. Lack of Reference: Since the thereminist does not actually touch the theremin, he has no point of reference for tuning notes and nothing to steady his hand. Theremin Solutions Dual Mode Theremin: A more versatile theremin will be able to switch from the original continuous frequency mode and a new discrete frequency mode that produces scales automatically. Foot Pedal: A foot pedal will allow instantaneous mute and unmute in order to produce easier staccato. Tuning: A reference for tuning will be provided for silently locating starting pitches and pitch verification during practice. Theremin will interface with common tuners. Theremin Design Requirements • Discrete Frequency Accuracy –Switchable between playing the traditional continuous range and playing only distinct frequencies in twelve selectable major scales with error < 0.1%. • Precise Articulation –A footswitch will connect to the theremin to enable the performer to quickly and easily articulate notes. • Tuning –A signal will always be present at the 1/4" tuner out jack to enable the performer to locate starting pitches and for pitch verification during practice. • Frequency Range –A frequency range of four octaves with a center frequency at 440Hz. Theremi n Design 1. Software Simulation • PSPICE, MATLAB 2. Hardware Testing • Breadboard circuits • Analyze differences between simulation and lab results. 3. Update Simulations Theremin Theremin Modular Design Variable Oscillator Fixed Oscillator Detector Freq-Voltage Converter PIC controller with A/D 14-bit D/A V/F Converter Discrete Frequency Controller Pitch Control Variable Oscillator Freq Switch Voltage Controlled Amplifier Audio Out Tuner Out Signal Volume Tuning VCA Processor Volume Control Output Control Footswitch Theremin Front Panel: Frequency Controls Key Continuous A Chromatic B G # C F Discrete b E D Discrete Mode Continuous Mode Discrete Mode B Flat Scale Traditional Operation Chromatic Key Circuitry Bypassed Bypass Right Selector Switch Bb C D Eb F G A Theremin Tuning FLAT A . IN TUNE B C . D . SHARP E F Sabine STX-1100 Theremin . G . Theremin Conclusions and Future Work • Our .1% pitch error limit may be more stringent than needed. Some common tuners accept up to .2% pitch error. • The discrete frequency output may have a different timbre than the continuous frequency output. A wave-shaping circuit could be added to give them similar quality. Theremin Time Line Semester One Month 1 Requirements Month 2 Month 3 Test Specification Month 4 Test Certification Design Document Simulation Semester Two Month5 Month 6 Month 7 Month 8 Final Design Document Documentation Design/Simulation Hardware Verification Packaging Presentations Theremi n THEREMIN Department of Electrical and Computer Engineering Test Specification Requirements Circuit Simulation Fixed Pitch Accuracy Foot Switch Frequency Range Physical Attributes Antenna Test Excel Oscilloscope Tuner Prototype Testing Power Signal Output Tuner Out Theremi n Discrete Mode Overview Frequency/Voltage 110-1760 Hz continuous beat frequency from detector Binary representation of selected output level PIC controller with 10 bit A/D Converter 0.3-5 V continuous voltage range 14 bit D/A Converter Voltage/Frequency Resulting discrete voltage level Converter Desired note within 0.045% error