In addition to the home dog, the most basic anti-theft alarm is a simple circuit to enter the way.
In any circuit, whether it's powering a flashlight or a computer, electricity flows only when you give it a path between two opposite charge points.
To turn the power on or off, turn on or off part of the circuit.
To turn the flashlight circuit on or off, just turn on the switch.
In an anti-theft alarm, the switch detects intrusion--
Open a door or window, for example.
These types of alarms fall into two categories: There are multiple ways to build this circuit into an input method.
A closed circuit is usually better than an open circuit because an intruder can deactivate the open circuit by simply cutting off the connected wire.
The magnetic sensor in the closed circuit consists of several simple elements.
For the most basic design you need: when the door is closed, the magnet pulls the metal switch off so the circuit is done.
The current supplies the magnet of the relay, so the buzzer circuit remains open.
When you open the door to move the magnet, the spring will return the Switch card to the open position.
This will cut off the current and turn off the relay to give an alarm.
You can also build such a system in a window.
If the intruder pushes the window open, the magnet slides out as the switch goes, and the buzzer is activated.
Another simple anti-theft alarm, with a small button as the switch.
The button is embedded in the door frame, so close the door and push it in.
When someone opens the door, the button is released, the circuit is changed and an alarm is issued.
These designs have only one battery and buzzer to serve a safety system with considerable defects.
After all, thieves can just turn off the buzzer by closing the door again.
That's why most modern anti-theft alarms add another piece to the circuit. -
The control box is connected to one or more alarm circuits, but it also has its own power supply.
It monitors the circuit and gives an alarm when the circuit is turned off or turned on (
Depending on the design).
But once the alarm is triggered, the control box won't cut it off until someone enters the security code on the connected keyboard.
To increase security, the control box is usually located outsideof-the-
So the intruder couldn't find it and tried to destroy it.
With this basic concept you can create various alarm systems.
Imagine what a thief might do in order to break into a house and then turn the action into a circuit switch.
For example, an intruder may break the window, so you can make the glass itself a circuit.
To do this, the easiest way is to run the current by a thin wire foil wire attached to the surface of the glass.
If a thief breaks the glass, the circuit is broken and the alarm is triggered.
The floor mat is another simple option.
The basic floor mat is designed with an open circuit, separated by two metal strips.
When someone stepped on the mat, the pressure pushed the two metal bars together to complete a circuit.
All of these circuit systems are best suited to protect the perimeter of a house or business--
The place where the intruder entered the building.
In the next section, we will look into the ability to detect an intruder or her system once it has entered the interior.