ECE5320 Mechatronics Assignment#01: Literature Survey on Sensors and Actuators Topic: MicrophoneOutline Reference listTo explore further (survival pointers of web references etc) Major applications Basic working principle illustratedClassificationClassificationClassificationClassificationClassificationClassificationA typical sample configuration in applicationA typical sample configuration in applicationA typical sample configuration in applicationMajor specificationsMajor SpecificationsMajor SpecificationsMajor SpecificationsMajor SpecificationsMajor SpecificationsMajor SpecificationsLimitationsECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Topic: MicrophonePrepared by:Balaji RavindranDept. of Electrical and Computer Engineering Utah State University3/6/20083/24/2008ECE5320 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– Limitations3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-3Reference list• Hearing AIDS: Standards, Options, and Limitations By Michael Valente• Robertson, A. E.: "Microphones" Illiffe Press for BBC, 1951-1963• http://arts.ucsc.edu/EMS/Music/tech_background/TE-20/teces_20.html• http://www.tonmeister.ca/main/textbook/node473.html• http://www.wikirecording.org/Condenser3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-4To explore further (survival pointers of web references etc) • http://www.listeninc.com/site/images/Microphone_Test_Setup.jpg• http://www.infineon.com/dgdl/smm310.pdf?folderId=db3a30431428a37301143a65efcb01df&fileId=db3a304314dca3890114f475ee1c06e8• http://hyperphysics.phy-astr.gsu.edu/Hbase/audio/mic.html#c3• http://en.wikipedia.org/wiki/Microphone3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-5Major applications • Recording Studios,• Telephones / Mobile / Voice Communication,• Hearing Aids,• Motion Pictures• University / Public / Private Conferences• Computers• Space Applications• Medical ApplicationsBasic working principle illustrated• Thin membrane – vibrating in response to a sound pressure – movement converted to electrical signal.3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-6Classification• Types – Capacitor or electrostatic Microphones– Dynamic Microphones– Piezo-electric Microphones– Carbon Microphones– Laser Microphones– Liquid Microphones• Type classification – classifies the diaphragm’s placement and position.3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-7Classification• Capacitor or Electrostatic Microphone– Diaphragm – one plate of a capacitor – vibration –produces changes in distance between plates– Voltage maintained across the parallel plates varies with vibrations – Q = C * V– Power is required for establishing the capacitor plate voltage and for internal amplification of output3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-8Classification• Dynamic Microphones– Works on Induction principle• Moving Coil Microphones and• Ribbon Microphones• No external power source required– Moving Coil – small movable induction coil – placed in the field of a permanent magnet – attached to the diaphragm3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-9Classification• Dynamic Microphones– Ribbon Microphone- Ribbon – electrically connected to the microphone’s output – vibration within magnetic field – generates electrical signal.3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-10Classification• Carbon Microphone– Carbon granules pressed between the plates – when diaphragm vibrates – adjacent granules change – this changes the electrical resistance of granules – this changes voltage and hence current flows – producing electrical signal3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-11Classification• Piezo - Electric Microphone– Uses piezo-electric crystals attached to diaphragm, which produces voltage when pressure is applied.– Such Microphones mostly used in musical instruments.3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-12A typical sample configuration in application• MEMS Microphone from Infineon– Based on MEMS technology– Assembled directly on PCB– Used in Mobile phones and medical appliances– Robust Design– High temperature stability– Alternative to traditional capacitor microphones– Surface Mountable Device3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-13A typical sample configuration in application3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-14A typical sample configuration in application• Figure shows a typical SMM310 microphone connected to a pre-amplifier circuitry.(Image Courtesy : Infineon Technologies)3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-15Major specifications• Major Specifications in a microphone are– Frequency response– Noise– Sound-Pressure Level– Clipping Level– Dynamic range– Sensitivity3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-16Major Specifications• Frequency Response– measure of any system's spectrum response at the output to a signal of varying frequency at its input.– In microphone, frequency response is a plot of the microphone’s sensitivity over a range of frequencies.3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-17Major Specifications• Noise– Sound level that creates the same output voltage as the microphone does in the absence of sound. – Represents the lowest point of the microphone's dynamic range.3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-18Major Specifications• Sound Pressure Level– Measured in terms of maximum Total Harmonic Distortion that the microphone can accept.– Higher the value, the better the microphone.3/24/2008ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-19Major Specifications• Clipping Level– Measure
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