Where-is-the-coil-in

Where is the coil in?

* In speakers such as Woofer, Sub-Woofer, Tweeter,
Car Speakers, HI-END Speakers and PA Speaker.
* Headphones
* Microphones
* Voice Coil Actuators which are in motors,
servo system, lens-focusing applications,
medical equipment and shaker tables.
* Inductive Sensors
* Electro Coil Sensors and Electro Coil Barriers in
security systems
* Car Engine
* Alarm System
* Hard Disk