AB-004: Understanding ERM Vibration Motor Characteristics …
AB-004 Understanding ERM vibration motor characteristics. Overview. The Eccentric Rotating Mass vibration motor, or ERM, also known as a pager motor is a DC motor with an offset (non-symmetric) mass attached to the shaft.. As the ERM rotates, the centripetal force of the offset mass is asymmetric, resulting in a net centrifugal force, and this …