ECE5320 Mechatronics Assignment#01: Literature Survey on Sensors and Actuators Topic: MicrophonesOutlineReference listTo explore further (survival pointers of web references etc)Major applicationsTypes of MicrophonesBasic Working Principles – Dynamic MicrophonesBasic Working Principles – Ribbon MicrophonesBasic Working Principles – Capacitive Condenser MicrophonesBasic Working Principles – MEMs MicrophonesBasic Working Principles – Piezoelectric MicrophonesMajor SpecificationsLimitationsSample ConfigurationMicrophone selectionSlide 16ManufacturersSlide 18ECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Assignment#01: Literature Survey on Sensors and Actuators Topic: MicrophonesPrepared by:Matthew D. CarneyDept. of Electrical and Computer Engineering Utah State UniversityE: [email protected] ; T: (435)797-4658; F: (435)797-3054 (ECE Dept.)W: http://ususat.usu.edu3/11/200501/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-2Outline –Reference list–To probe further–Major applications–Basic working principle illustrated–A typical sample configuration in application (application notes)–Major specifications–Limitations–And many more relevant issues in applications (such as, how to choose, cost information, where to buy etc.)01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-3Reference list•http://mechatronics.ece.usu.edu/ece5320/hw01-2004/Clint_E_s.ppt © 2004 Clint Ellis•Bernstein, J, MEMS Air Acoustics Research, Draper Laboratory, DARPA Aug 1999•Friot, E., Bordier, C., Real-time active suppression of scattered acoustic radiation, Journal of Sound and Vibration, 278 (2004) 563-580•Biersdorfer, J.D., Headphones that make the world go away, New York Times, Sept 30, 2004, pg G6•http://www.audiotechnica.com/using/mphones/guide/micdoes.html01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-4To explore further (survival pointers of web references etc) •http://www.siemens-hearing.co.uk/00_uk/10_products/17_technology/Technology.jsp•Sanliturk, K.Y. , Cakar, O. Noise elimination from measured frequency response functions, Mechanical Systems and Signal Processing, May 2005, Vol 19, Issue 3 p615, 17p01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-5Major applications •Sound suppression•Noise elimination•Sound recording•Sound amplification•Voice Recognition01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-6Types of Microphones•Dynamic- Ribbon•Condenser–MEMS–Capacitive•Piezoelectric01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-7Basic Working Principles – Dynamic MicrophonesDynamic MicrophonesA coil moves when sound waves hit the diaphragm, and the movement creates a small current. This is similar to a loudspeaker, only in reverse. Courtesy www.mediacollege.com01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-8Basic Working Principles – Ribbon MicrophonesRibbon MicrophonesA thin, conductive ribbon is placed in a magnetic field. As sound waves move the ribbon, an electric current is induced in the ribbon. Courtesy hyperphysics.phy-astr.gsu.edu01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-9Basic Working Principles – Capacitive Condenser MicrophonesCondenser microphones use lightweight membrane and a fixed plate, acting as opposite sides of a capacitor. As sound waves strike the membrane, the capacitance changes, changing the properties of the circuit. Courtesy www.audiotechnica.com01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-10Basic Working Principles – MEMs Microphones Courtesy DARPAMEMS microphones work in a similar fashion as standard condenser microphones, but are highly sensitive and very small. They are placed on JFET amplifiers to reduce stray capacitances. They also detect infra and ultra sound.01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-11Basic Working Principles – Piezoelectric MicrophonesThe same principle holds as in other designs, as the diaphragm is activated by sound waves, it will deform the crystal, and a voltage is createdCourtesy www.hit.bme.hu01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-12Major Specifications•Frequency Response•Sensitivity•Dynamic Range•Impedance•Bandwidth01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-13Limitations•Attenuation•Directionality•Sensitivity•Frequency Response01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-14Sample Configuration•Real Time Active Sound Suppression01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-15Microphone selection•Directionality–What sort of pattern is needed?–Less direction is needed when close to source–Microphone directionality is similar to antennas•Frequency Response–Select microphone for desired frequency–Flat response pattern is best–Condenser is flatter than dynamic01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-16Microphone selection•Impedance–Low impedance is superior–Must be matched to other circuitry•Noise–Should have a mechanical protection system to insulate it from vibration.01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-17Manufacturers•Dynamic–Siemens–Bose–Phillips•Condenser–Americor Electronics–MynTahl Corporation01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-18Manufacturers•MEMS (DARPA issued licenses)–Siemens (Munich)–National
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