PIR MOVEMENT ALARM


      The unit consists of a passive infrared detector. The sensor detects the infrared rays emitted by humans. The sensor o/p is connected to a circuit, which triggers an alarm when infrarred rays are detected. The unit when switched on becomes active after 30 seconds. During this time it does not detect infrared rays. After 30 second if any person enters the room the infrared rays emitted by the person are detected & alarm operates with in 20 seconds. The alarm operates for 1 minute & stops & the unit is ready to dectect further interference. If the person does not vacate the room the alarm continous to operate. The unit is useful for a hall of 25' x 25' if fixed at one corner.. The unit has a master key to switch on & off.