The act of interrupting an electric current, beam of light, or beam of infrared radiation at regular intervals. This can be accomplished mechanically by rotating a vibrating mirror in the path of the beam to deflect it away from its intended source at regular intervals. A current can be chopped with an electromagnetic vibrator having contacts on its moving armature. A current can also be chopped electronically by passing it through a multivibrator or other switching circuit. Chopping is generally used to change a direct-current signal into an alternating-current signal that can more readily be amplified. Control systems for guided missiles make extensive use of chopping.