หวยลาว 3ตัวตรง (ชุดเดียว) 8/5/62
Aerospace relays are electrically controlled devices that open and close electrical contacts to effect the operation of other devices in the same or in another electrical circuit. The relay converts electrical energy into mechanical energy through various means, and through mechanical linkages, actuates electrical conductors (contacts) that control electrical circuits.
from: http://ezinearticles.com/?Aerospace-Relays&id=3353512
