1 / 6

Electret Microphones

Electret Microphones. Michael Chakinis, Brianna Undzis, Swan Htun, Barrett Neath. How Regular Microphones Work. Sound propagates through air in the form of waves A thin, flexible diaphragm is contacted by waves Moving diaphragm creates varying current Dynamic Induction Condenser

nancyd
Télécharger la présentation

Electret Microphones

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Electret Microphones Michael Chakinis, Brianna Undzis, Swan Htun, Barrett Neath

  2. How Regular Microphones Work • Sound propagates through air in the form of waves • A thin, flexible diaphragm is contacted by waves • Moving diaphragm creates varying current • Dynamic • Induction • Condenser • Capacitance • Ribbon • Induction • Crystal • Piezoelectricity effect

  3. How the Electret Microphone Works • The electret condenser microphone works on the principle of variable capacitance • Use a parallel plate capacitor with a fixed and moveable plate • When sound waves hit the moveable plate, it changes the capacitance and electric flow • They’re made by melting a dielectric material then solidifying it to a strong electrostatic field • Being chemically stable and having high resistance embeds a permanent electric dipole moment • It can be connected to a JFET (Junction Field Effect Transistor) to increase the generated electric current

  4. Different Types of Electret Microphones • There are three main types of electret microphones: front electret, back electret, and foil-type. • Front Electret • Newer • Back plate eliminated • Capacitor formed by diaphragm and inside surface of capsule • Electret, inside front cover • Any conductive film may be used for diaphragm • Back Electret • Electret film applied to back plate of microphone capsule • Diaphragm, uncharged materials • Transducer design • Physical quantity -> electrical signal • Foil-Type • Film of electret used for diaphragm • Most common • Lowest quality

  5. Relevant Equations • Variations in air pressure is detected by the diaphragm. • The voltage change is induced by the varying distance between the diaphragm and the back plate due to voltage fluctuations across the capacitor. • Thus, across the the diaphragm and the back plates, the voltage varies accordingly with the vibrations in the air given by the capacitance equation: • C = Q/V

  6. Sources https://en.wikipedia.org/wiki/Electret_microphone https://www.mediacollege.com/audio/microphones/how-microphones-work.html https://www.engineersgarage.com/insight/how-electret-condenser-microphone-works http://hades.mech.northwestern.edu/index.php/Microphones https://www.cui.com/product-spotlight/electret-condenser-microphones

More Related