서보모터
====== 구입처 ======
  *[[http://www.dealextreme.com/details.dx/sku.12859|TowerPro SG90 9G Mini Servo with Accessories]] in DealExtream
====== references ======
  *[[http://www.instructables.com/id/Simple-Servo-Tester/|Simple Servo Testor - using 555]]