Alarm warning when animal is about to give birth - sends radio signals when animal lies on her side via mercury switches

摘要

The system consists of a detection and transmitter unit, strapped to the animal's back, and a receiver and alarm unit, within a radius of about 150 metres. The detector and transmitter unit consists of a plastics material housing (1) containing a pair of mercury switches (3), a transmitter circuit (2), arial (4) and battery (5). When the animal lies on her side, a position only adopted when giving birth, the mercury droplet shorts contacts together, causing the alarm to be transmitted. After a delay to avoid false alarms, the receiver produces an audible alarm. The delay time and angle of the switches can be adjusted to allow for the difference between mares, ewes and cows. @(7pp Dwg.No.4/7)@.