how to use the home burglar alarm systems?

Now more and more people focus on the home alarm system to protect the privately place's peace and the

When the door is closed, the magnet pulls the metal switch closed so the circuit is complete. The current powers the relay's electromagnet, so the buzzer circuit stays open. When you move the magnet by opening the door, the spring snaps the switch back into the open position. This cuts off the current and closes the relay, sounding the alarm.

You can also build this sort of system into a window. If an intruder pushes a window open, the magnet slides out of line with the switch, and the buzzer is activated.

Another simple burglar alarm uses a small button as the switch. The button is embedded in the door frame, so closing the door pushes it in. When somebody opens the door, the button is released, changing the circuit and sounding the alarm.

With just a battery and buzzer, these designs make for fairly flawed security systems. After all, the burglar only needs to close the door again to turn the buzzer off. That's why most modern burglar alarms incorporate another piece into the circuit -- the control box.

The control box is hooked up to one or more alarm circuits, but it also has its own power supply. It monitors the circuits and sounds the alarm when they are closed or opened (depending on the design). But once the alarm is triggered, the control box won't cut it off until somebody enters a security code at a connected keypad. For added security, the control box is usually positioned in an out-of-the-way spot, so the intruder can't find it and attempt to destroy it.

Property loss.