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Most driveway alarms are battery powered wireless units with a transmitter and receiver. They come in a wide variety of types and distance capability. In general, you should look for a unit that can transmit at least 25% farther than the distance between the transmitter/receiver pair. This will ensure the receiver can detect the signal from the transmitter and respond. Also, decide if you want to be alerted to anything moving on your driveway, or just vehicles. If you live in a rural area, animals could cause a lot of false alarms. The waterproof transmitter is placed close to the driveway. It is usually a PIR (Passive InfraRed) unit that responds to changes in infrared radiation from objects up to about 30 feet away. It’s important to point the transmitter in the general direction of the receiver. Do not point it at objects that give off a lot of heat such as air conditioners, or sources of bright light. These give off infrared radiation and could prevent the transmitter from responding. The receiver is placed in a convenient location inside the home. It should generally be in a spot where it points toward the transmitter for best performance. If you have the option of plugging the receiver into an electrical outlet, that will save the batteries. However, you should still install batteries (as long as this is recommended by the manufacturer) so the unit will work during power failures. Driveway alarms can also be purchased with an option that allows connection to outdoor lights. When you arrive home in the evening, the lights would be triggered. This also helps thwart undesirables from approaching your home. |
Home Security – Driveway Alarms
January 26, 2008 by Ken
