The purpose of the alarm is to sound the alarm in different situations that threaten the safety of the vehicle. This may be an open door or window, a collision or a touch of a car, entry into the passenger compartment, etc. History of car alarm development
History of car alarm development
The first was the system to signal when the car was rocking: for example, if the attacker intended to remove the wheels of the car.
Over time, the "cachting" sensors have replaced the so-called "shock sensors", or, more simply, the impact sensors. But they were waiting for them to be upgraded-two-threshold stroke sensors: the first threshold was triggered by a minor impact (including a warning short signal), the second, less sensitive, activated at greater impact (the siren activated).
"Heart" of any security system-center block with microprocessor
Now there are several types of sensors with different sensitivity, device and purpose: ultrasonic (also known as "Ultronic"), microwave, voltage-drop sensing and control type sensors. They are also distinguished by an alert system: it may be a siren, light-emitting diode, or light indication, and a combination of them.
car alarm device
The "heart" of any security system is a central unit with a microprocessor. It is the one that receives signals from sensors, sensors and a remote control, and also controls the operation of the entire system. The information received is processed, and then the central block sends signals to warn the driver in some way of an unauthorised situation, such as system problems, unauthorized entry or interaction with the car. In addition, the center of the center interacts with the central lock of the car-at the same time the opening and closing of doors takes place.
The car alarm can be performed as a single unit of the main computer with a siren and sensor, or may be performed on a posted circuit when all the elements are in different locations. However, for European cars, it is the monobal structure that is most typical, and in the machines of American production, on the contrary, they use a posted design.
The system is managed by a remote control account, which is more often made in the form of a key fob, which is convenient to store with car keys. The signal from the key to the central block is transmitted via radio antennas. There are several control buttons on the log, and the most expensive even have a small screen, which shows the current information about the car. The remote control is operated by the battery and its zone of action depends on the manufacturer-it is usually 20 to 60 meters.
For the protection of the convertible, microwave sensors, which cover the car with two fields and record their penetration into them, are used
There are remote controls that do not transmit the radio signal, and the infrared light is particularly characteristic of German cars. These beams operate on the principle of a traditional TV remote: the device has a relatively small range of actions, and it is necessary to send it to the receiving mechanism.
Varieties of signalling sensors
The next important element to focus on is the sensors. As stated above, they differ in the sensitivity and the principle of action. However, they all pass information to the main control unit. Here are the basic types of sensors:
The shock sensor or impact sensors, as the name suggests, react to the impact on the body of the vehicle. They differ in the number of threshold sensitivity. Most often, a warning short signal is triggered with a slight touch of the body, and the siren is activated in a strong impact.
Ultrasonics, or ultrasound sensor, reacts to the intruder's entry into the salon. It consists of two remote microphones placed inside a car. It works in the following way: a highly sensitive sensor indicates the distortion of the ultrasonic wave-and the alarm system activates. His main disadvantage is heightened sensitivity-he can raise the alarm even when the temperature is changed in the passenger compartment.
Microwave sensors are used to protect the convertible. The working principle is as follows: The sensor covers a vehicle with two fields, respectively, has two thresholds. The first extends outside the car, the other controls the passenger compartment. The alert system also works like the two-threshold impact sensor. If he's got an intruder in the first field, a warning will be triggered if the hijacker's inside the salon-the siren's on.
The voltage drop sensor is designed to protect the car from power-out. There are many variants of carjacking, and one of them is to de-energize the car by building a battery. The attacker works with the battery, resulting in an electrolyte and a car. So the sensors, as you can guess from the name, respond to the fall and the jumps.
Leatherback sensors or contact type sensors are buttons controlling the condition of doors, bonnet and luggage racks.
How the alarm can be alerted to danger
So, the sensors react to the events, send the signal to the central control unit, and then the alert is triggered. It can have more than one type of occurrence. The first and most common is the siren. It produces a sound signal of up to 140 Db and usually works for 45 seconds, if the remote control does not advance the command of its decontamination.
That the car is equipped with a security system, will be told by a flashing light-emitting diode, which is usually located at the base of the windshield.
The light indication is another alert option that can also be used in a pair with a sound signal. During an alarm, the car may blink headlamps, dimensions or accidents.
