Wireless solar infrared beam in perimeter alarm system

Perimeter protection is the first defense line for the intrusion detection, it's most important and crucial for the whole security system. Now with different technology, there are two different perimeter protection: Active infrared beam and electric fence. Electric fence with disadvantages of high cost and appearance, effectiveness, so the electric fence doesn't widely used in perimeter protection.  On the contrary, active infrared beam sensor occupied most market for the perimeter protection projects. Even though compare with electric fence, installation for the infrared beam sensor is pretty easy,  but the wiring, construction works are very hassle.

Wireless solar infrared beam working theory

For better meet the demands from security market, now some manufacturer launched some new perimeter sensors - wireless solar active infrared beam sensor. Utilising wireless and solar technology solved the troubles when install and maintain the perimeter sensor. The basic design layout main features as below:

1. Beam sensor (infrared beam receiver and transmitter) is equipped with rechargeable battery, power supply adopts solar panel, so the system recycling use the solar power without any power supply cable wiring. Typically, the solar panel using the amorphous silicon material which can generate electricity even without direct sunshine, this can make the solar beam sensor working in various envrionment. In addition, the power supply from solar panel is high than beam sensor's consume, insure the infrared beam can work at night and continuous raining day.
2. Beam sensor built-in wireless signal transmitter, the wireless signal transmitter can link the sensor to alarm panel. When infrared beam sensor is triggered, it will send wireless signal out to wireless alarm panel.

Wireless solar infrared beam sensor utilized solar power, transmit signal via wireless technology, without cable wiring, it's complete wireless beam sensor, effectively solved the problems for beam's installation, it's working theory is similar to wired infrared beam sensor, but degrade the power consumption.

Disadvantages and solution

1. Wireless transmission range limitation.  Currently solar power wireless transmission distance among 100 meters.  In order to expand the wireless transmission distance, it's possible to use high power RF transmitter. Please bear in mind you can not install the wireless solar beams in signal shield environment, it will stop the wireless beam sensor transmit wireless signal out.
2. Low illumination environment cannot be used, due to low illumination may not make the solar panel to generate sufficient electricity to charge the battery.

Above two disadvantages are related to the hardware technology, it may cannot be solved completely.  Reducing the problem from the ligh condition, wireless solar infrared beam sensor using special material to insure the infrared beam can work at  low illlumination condition, the amorphous silicon working at 1600LX (Normal raining weather: 2000LX) light condition, the solar panel can output the current, event the ligh is insufficient, the beam still can work.