A dynamic microphone is an example of dynamic transducer. The principle of dynamic transducer is a movement of a thin metallic diaphragm because of sound wave. This diaphragm attach coil of wire. Based on Faraday’s electromagnetism law there will current flow caused by the motion of within the field. The motion speed affect the current amount that is produced by the dynamic transducers. Figure below illustrates how the dynamic transducer works:
Dynamic Microphone circuit schematic
Dynamic microphones that use dynamic transducer is called as velocity sensitive. This kind of microphone has some advantages such as no battery or external power supplies required, durable, their and reliability ruggedness and can produce extremely high sound levels without excessive distortion or damage. It also capable to produce smooth extended response and can be easily “tailored” in response for special applications. However, for the extreme frequencies, this microphone can’t give good response. This mic is the best choice if it used in “severe environments” like fellowship halls, outdoors, etc.