| "body"> | | | | pushes the button open and closes the circuit, |
| Have you ever wondered how your car security | | | | sending electricity the alarm and siren. Most car |
| alarm works? Contrary to what you might think, car | | | | security alarms systems have very useful accessories |
| alarms are actually pretty simple devices - they're | | | | such as a radio receiver for wireless control from a |
| just a set of sensors connected to a siren. | | | | key, and backup batteries that allow alarms to work |
| A car security alarm typically has six parts - a siren | | | | even when the main power source gives up. Most |
| (the device responsible for making the noise) and five | | | | car security alarms have sirens that are capable of |
| sensors (window, door, pressure s, shock, motion | | | | creating distinct sounds so that the owner can pick |
| and tilt sensors). The simplest car security alarms | | | | out a sound pattern and be able to tell if it is his or |
| work mechanically - if someone tries to force the | | | | her car that's sounding an alarm. |
| door open, for example, the car door sensor sends a | | | | The most recently developed car alarms offer |
| signal to the siren, which in turn makes loud sounds. | | | | features that promise to deter car theft more |
| The technology behind door sensors is actually the | | | | effectively. Among these new features are small |
| same technology used in your refrigerator. Notice | | | | computers that are designed to outsmart thieves. |
| how your refrigerator lights turn on when you open | | | | When an intruder cuts off the main power source of |
| the door and turns off when you close it? Both | | | | the car alarm system to prevent it from sounding |
| technologies are actually simple circuit systems - | | | | off, the computer (powered by a hidden battery) |
| when someone forces the car door open, the spring | | | | triggers the siren to sound the alarm. |