ECE5320 Mechatronics Assignment#01: Literature Survey on Sensors and Actuators Topic: LoudspeakersOutlineReference listTo explore furtherMajor applicationsBasic Working PrincipleSample ConfigurationSlide 8Slide 9SpecificationsSlide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18LimitationsLoudspeaker SystemsSlide 21Slide 22LoudspeakersECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Assignment#01: Literature Survey on Sensors and Actuators Topic: LoudspeakersPrepared by: David D. BradshawDept. of Electrical and Computer Engineering Utah State UniversityE: [email protected] ; T: (435)797-1000; F: (435)797-3054 (ECE Dept.)W: http://mechatoronics.ece.usu.edu3/9/200701/13/19ECE5320 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–Loudspeaker systems–Where to buy01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-3Reference list•Yamaha Sound Reinforcement Handbook. Davis & Jones, 1989. Hal Leonard.•Sound System Engineering. Don and Carol Davis. 1987. Howard W. Sams and Co.01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-4To explore further •http://www.scrounge.org/speak/speak.htm•http://www.kbapps.com/construction.html•http://www.geocities.com/SunsetStrip/Stage/4241/Setup.html•http://www.sweetwater.com/shop/live-sound/8_steps_pa_system.php•http://www.audioholics.com/tweaks/speaker-setup-guidelines01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-5Major applications •Sound reinforcement and public address systems•Alarm and security systems•Home and mobile audio systems•Home theatre systems•Voice and audio communication systems01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-6Basic Working PrincipleA loudspeaker transforms electrical energy into mechanical vibrations that are propagated into the air0 1 2 3 4 5 6 7 8 9 10-1-0.8-0.6-0.4-0.200.20.40.60.81http://www.privateline.com/TelephoneHistory/soundwaves.html01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-7Sample ConfigurationHome theatre system: PrincipleA home theatre system consists of a loudspeaker array arranged in such a way as to simulate a natural acoustic environment. A sound distribution system sends electrical power to certain loudspeakers in varying levels to give the perception of reproduced sounds coming from a specific place.01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-8Sample ConfigurationHome theatre system: wiring diagramhttp://www.onqlegrand.com/jahia/Jahia/pid/138301/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-9Sample ConfigurationHome theatre system: loudspeaker placementhttp://www.guardianhometechnologies.com/what-we-offer/Home-Theatre-Systems.html01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-10SpecificationsMajor Specifications:•Frequency response•Resonance•Nominal impedance•Power rating•Sensitivity01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-11SpecificationsFrequency responseSpecified as the range where the magnitude response is above -3dB Example: 15Hz - 40 KHzComplex frequency response can also be specified using a Bode plotExample:http://www.linkwitzlab.com/images/graphics/p5.gif01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-12SpecificationsResonanceSpecified as the frequency where the peak magnitude response occurs. Resonance can be specified or read directly from a bode plot.01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-13SpecificationsNominal Impedance•Since the impendence of the loudspeaker changes according to the input frequency, a nominal impedance is often specified. •This nominal impedance represents the minimum impedance across the input terminals. •Nominal impedance may be specified or derived from an impedance response plot.01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-14SpecificationsNominal Impedancehttp://www.partsexpress.com/projectshowcase/dkhts/frntimp.jpgThe nominal impedance of this loudspeaker is 4 ohms01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-15SpecificationsPower RatingPower ratings indicate how much power the loudspeaker can handle without damage. Power ratings can be specified in two ways: •RMS (or program) power•Peak power01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-16SpecificationsPower Rating: Peak PowerPeak power ratings indicate how much power the loudspeaker can handle for a very short time.Inexpensive louse speakers often only specify peak performance01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-17SpecificationsPower Rating: RMS PowerRMS power ratings indicate how much power the loudspeaker can handle continuously. It is the average power dissipated in the loudspeakerIf RMS power rating is not specified, it can be estimated as being roughly half of the peak power capactiy01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-18SpecificationsSensitivity•Sensitivity ratings are specified as a dB sound pressure level output (SPL) for a given input power, measured a certain distance from the loudspeaker. •Sensitivity is usually specified as db SPL at 1 meter from the loudspeaker for a 1W input.• It is important to understand that a loudspeaker with a higher sensitivity will sound louder than a loudspeaker with a lower sensitivity at the same power rating!01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-19LimitationsLimitations of loudspeakers• require high drive current when implemented using permanent magnet coils• performance usually optimized for the range of human hearing ( 20 Hz – 20 KHz )• loudspeakers are directional due to the need of baffles to increase loudspeaker efficiency01/13/19ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuatorsSlide-20Loudspeaker SystemsTo increase efficiency, loudspeakers are often used in multiple loudspeaker configurations. In these loudspeaker systems the
View Full Document
Unlocking...