The reed switch is the most important element of protection against theft. Installing an additional sensor (reed switch) on the gas tank hatch Anti-theft on the reed switch and relay
To switch various parts electrical circuits different switching devices are used. One of them is a reed switch, the main application of which is automation and security systems. To properly install the device, it is important to know what a reed switch is and how it works.
Description of the device
The name "reed switch" comes from the abbreviations of two words - "sealed" and "contact". This sealed device is a pair of ferromagnetic contacts placed in a glass bulb. The contacts simultaneously serve as a magnetic conductor, a current conductor and a spring. Inside a sealed flask there may be a vacuum, an inert gas, or a drop of mercury. The closing and opening of such a device is controlled by exposure to an external magnetic field. This field can be created as permanent magnet, and an electromagnet.
Reed switches peaked in the 1970s, and are now being replaced in many applications by solid-state elements - Hall sensors
How the reed switch works
The principle of operation of the device is based on the interaction of a magnetic contact located inside the device and an external magnetic field(MP). As a result of this interaction, a force appears that presses (or pulls) the contact. Depending on the initial location of the contacts, the reed switches are:
- with breaking contacts;
- with closing contacts;
- with changeover contacts.
Since the beginning of the 2000s, there has been a trend towards the use of miniature reed switches with hypersensitivity, speed and resonant frequency
The reed switch of the first type is closed in the initial state. When MF appears, the contacts open. The device of the second type works the other way around - the contacts close when exposed to the field. The reed switch of the third type, when a magnetic field appears, opens one circuit and closes another.
What is it for
Reed switches are commonly used as sensors, trip and changeover contacts.
Due to the presence of sealing, reed switches can be used to work in a humid and aggressive environment, as well as for underwater systems.
Compared to conventional relays, reed switches have a number of advantages:
- small dimensions;
- greater reliability;
- short response time
The disadvantages of reed switches include:
AT various systems reed switches are used to switch electrical circuits. A feature of these devices is that the contacts in them are sealed, and they are controlled by an external magnetic field.
The big priority of the "secret" is its invisibility and individuality!
« Secret from theft» is simpler, but at the same time effective method secure the car.
Installing a secret button or lock on a car has always been considered the most reliable way to protect your car.
In spite of big choice modern car alarms, as well as immobilizers and other anti-theft systems, it is the secret button that can drive the hijacker into a dead end and greatly increase the time of car theft.
Installation of locks on the car:
- - original reed locks
- - sensory secret
- - ignition lock
- - fuel pump lock
- - electronic secret
- - lock for injectors
- - locks for starting the engine
The secret button can be located anywhere in the car. It can be any regular button in the car, additional button, or reed switch, magnet ...
Installing a secret won't take long. Our masters will qualitatively and on time install the secret button for you. We will help you choose a place for a secret button, thereby increasing reliability. security functions your car.
We RECOMMEND you to install in addition to the secret button alsoHood lock , its effectiveness is very important in car protection.
Secret on the relay
The principle of operation of the secret is as follows:
When the ignition is turned on, the IGN1 circuit remains broken until the moment the secret button is pressed briefly. The circuit remains closed until the ignition is turned off.
Installing a simple secret on a relay - 2800r.
Secret from theft on the reed switch
Increased secrecy at work.
The advantages of a secret on a reed switch are obvious.
If the secret on a regular regular button is elementary to reveal, then with a reed switch everything is much more difficult.
The reed switch can be very well and discreetly hidden behind the car's upholstery.
And it will be very difficult for hijackers to find such a secret from theft.
You do not need to do anything to attract attention, but simply hold the magnet directly next to the place where the reed switch is hidden.
And the car is ready to go.
Everything is simple and hidden as much as possible.
Installing a secret on a reed switch - 4000 rubles.
Secrets Meguna Sphinx – Smart secrets – Ability to work with autorun systems
The Sphinx immobilizer is an intelligent means of protecting a car from theft. The Sphinx has a control principle that is understandable for the car owner and, due to the presence of a motion sensor, the most advanced engine blocking algorithm to date with imitation of a malfunction.
In case of an unauthorized start (the Sphinx is in armed mode), the engine will run for an arbitrarily long time on a stationary machine - with this algorithm of work, it is impossible to calculate the blocking and neutralize it.
After an attempt to move off, the brake lights of the car will light up and the immobilizer will block the engine. Within 5 seconds after the engine is turned off by the immobilizer, it is impossible to disarm the Sphinx!
30 seconds after the ignition is turned off, a motion sensor is activated that monitors the change in the position of the car in the parking lot.
Installation of a smart secret Sphinx - 5800 rubles.
Installing an anti-theft lock.
Installing a car anti-theft lock requires the most serious approach. The reliability of its operation and, accordingly, your confidence in the protection and safety of the car depend on how well and professionally the system will be installed.
AutoSub installation centers offer their customers the installation of electronic locks - with high quality and reliability. AvtoSab is a certified center and has a certificate for such work - when contacting our centers, you can be sure of the quality of the services provided, and your car will not lose the dealer warranty, which is so important for any car owner.
It is quite logical that every car owner wants to know exactly where his vehicle is and, if possible, protect it from intruders. Unfortunately very difficult protective systems are often inconvenient for the owner. Yes, and they do not provide protection at the level that we would like. For example, alarms annoy passers-by, but they do not protect against criminals, since they have long learned to neutralize them without any difficulty. A truly reliable protection for a car today is a secret from theft. Installation of secrets is carried out by specialists of our company. Also within the scope of our competence is the installation of search engines on cars.
Anti-theft locks are very easy to use equipment. The mechanism of operation of such a device is elementary: the lock blocks the engine if the driver is not the owner of the car, but another person. In this case, the attacker will think that a banal malfunction of the car has occurred, since the device does not show its work in any way. The optimal solution is setting search engines along with a secret. So you can be sure of comprehensive protection your car.
The secret is endowed with a switch, a button or magnetic reed switch. And only the driver knows about their location. You can independently choose a place where the button will not be found by the criminal. But even if the toggle switch is detected by an attacker, after some time (you set it) the secret will completely block the ability to start the car. In general, the anti-theft car lock mechanism is very simple and therefore as reliable as possible. If you need to install locks on the car High Quality please contact our company.
Installation of anti-theft hood lock.
Hood locks are designed to prevent hidden access to the engine compartment of the car.
The inaccessibility of the engine compartment is an important element in protecting the car from theft.
Engine compartment protection, as a rule, creates serious obstacles for the hijacker:
Does not mute car alarm siren
Does not allow you to restore engine locks located under the hood
Does not allow you to start the car using an autonomous (non-standard) engine management system (the so-called "spider"), as well as autonomous system food
does not allow replacing the engine control controller (to bypass the standard immobilizer)
makes the diagnostic connector inaccessible (in cases where it is located under the hood), making it difficult to detect blockages and manipulate the standard immobilizer
makes it much more difficult to steal at the stage when the car alarm has already been neutralized (the radio channel code has been opened or selected), but an unrepaired engine block remains under the locked hood
Hood locks provide the greatest degree of protection in combination with an alarm or immobilizer.
ECU protection - electronic engine control unit.
Replacing the electronic engine control unit (ECU) is the easiest and most affordable way bypass the immobilizer.
It is enough to replace it under the hood and turn the ignition switch.
Another way is to register, using a dealer scanner, an additional key through the diagnostic connector.
Both methods will take a professional no more than a minute.
In this regard, the protection of the ECU and the diagnostic connector is very important.
One of the most reliable ways of protection is to restrict access both to the engine compartment using the hood lock, and to the ECU itself.
To do this, a metal casing is made, which is fixed using a special “breakaway” fastener that prevents the removal and replacement of the computer.
To protect the diagnostic connector, it is replaced with a non-standard one, with the manufacture of an adapter.
Unsoldering the diagnostic connector.
Unsoldering the diagnostic connector will not let hijackers
- Reprogram your factory immobilizer
- Detect blocking from security systems using diagnostic equipment
In this small article, I want to offer many drivers, both motorcycles and cars, a very simple and cheap, but despite this very reliable anti-theft device, which will not allow intruders to start the engine of any of your vehicle. In addition, such a device can be added additionally to the factory anti-theft system already installed on your device, which will double the safety of your property.
The basis of this inexpensive system is the reed switch, which is marked with the letters SF1 on the electrical diagram on the left, and in the radio store it can be found under the KEM-2 marking. The reed switch will need to be hidden in a secluded place, for example, under the skin of the seat, or under some kind of plastic part cladding, but in such a way that you can easily get to it with a magnet.
The reed switch will need to be included in the circuit of the car light relay, as shown in the electrical diagram on the left, and buy the relay in the store exactly the headlight relay, which is designed for long work(unlike signal relay). The relay marking on the electrical circuit is K1, and in the store when buying, be guided by the marking - 90.3743 or 90.3743-10. The relay contacts will break the primary circuit of the ignition coil.
When you assemble the circuit, the system will work in this way: you bring the magnet to the cache (I advise you to drill a hole in the magnet and hang it on the ignition key ring instead of the key fob), in which the reed switch is hidden, and at the same time the reed switch contacts are closed, the thyristor VS1 (marking KU201A ) will open and remain open until you turn off the ignition. In this case, the current flows through the winding of the relay K1, which is triggered and closes the circuit (applies power) to the primary winding of the ignition coil. Now you can start the engine.
Upon arrival, when you need to turn off the engine, you turn off the ignition and the system will automatically switch to watchdog mode, that is, until you bring the magnet to a place that only you know, it is useless to start the engine of your motorcycle or car, since there will be no spark.
Some thieves can connect the ignition coil with a piece of wire directly from the battery, if, for example, your ignition coil is not located somewhere under the tank, but in a conspicuous place. Then I advise you to put the wire from the 30th contact of the relay not to the ignition coil, but to the positive wire that supplies power to the switch, and hide the switch away (if you have electronic ignition). You can read how to install electronic ignition on a motorcycle, as well as. An electronic ignition can be made for a car in a similar way, although ready-made kits are sold for domestic cars.
To install such anti-theft system on a diesel engine, all you need to do is connect the wire from the 30th relay contact to the electro-valve on the injection pump of your engine, which shuts off the fuel supply when we turn off the engine. It is usually located on top of the high pressure pump (high pressure fuel pump), and who still can’t find it, then look at the manual (instructions for your engine), or ask an auto-electrician to find the electro-valve and connect the system to the valve.
I submit for consideration a development that is useful, in my opinion: replacing the mechanical limit switch of the rear door (trunk lid) 2111 with a reed switch and installing additional lighting in the trunk.
So essentially. The most common option for installing a trailer is a bracket with a trailer, actually fixed to the body.
Classic installation of the limit switch photo taken from the forums
The main disadvantage of this design for the station wagon 2111 is the fragility of the limit switch and bracket with the active use of the trunk (boxes, tools). For half a year, 2 limit switches were broken, so I set out to solve this problem in the bud. Options for drilling the body under the trailer did not impress either new typewriter, not now, after 7 years of operation.
Therefore, the choice fell on reed switches used everywhere in security systems, automation, etc. I didn’t see open reed switches and didn’t have it at hand (probably exist), reed switches with a switching group were rejected due to low sensitivity. Therefore, a conventional reed switch with a normally open contact was used - it is not at all a problem to find it, the cost is minimal.
Classic limit switch and reed switches
As you know, car alarms respond to contact opening (alarm). Therefore, I had to assemble a simple key that inverts the signal from the reed switch. And since there is a key, why not hang additional trunk lighting on it, independent of parking lights! The diagram is shown below.
So about the details, assembly, installation. The device works extremely simply: the trunk is closed - the reed switch is closed - the transistor is closed - the alarm input is NOT CLOSED to ground. The trunk is open - the reed switch is open - the transistor is open through the resistor R1. The alarm input is shorted to ground through the VD1 diode (a voltage drop of about 0.6V is not critical for alarm).
At the same time, an additional line sits on the ground. lampshade lighting.
- 1. Reed switch - common, used in security systems (SOMK-xx, Satel and similar). I chose from several options in terms of sensitivity - with a standard magnet from the SOMK kit - I got a reliable response from 30mm (quite enough), if you use magnets from computer hard drives - it will turn out even more (up to 50-60 mm).
- 2. Field-effect transistor– any N-channel low voltage power MOSFET. These are widely used in motherboards in power stabilizers of the processor and chips. It is impossible to enumerate all types, Practical parameters. are not critical for this scheme.
- 3. Any low-power diode - in case the trunk and hood limit switches are connected in parallel to the only car alarm input (hood_trunk).
Because the transistor used is powerful enough (switching currents from 15A and above, minimum voltage drop) - add. trunk lighting can be of any power.
Everything is assembled on a breadboard, a heat shrink tube is put on top.
I put a hard shell on the reed switch (came up from the RG58 cable), and heat shrink on top. The length of the wires to the reed switch is enough 20-25 cm. The board is fixed in the rear niche to the wiring harness. The “mass” from the pin was also taken there. The reed switch is fixed with ties to the trunk upholstery under the seal.
A feature of the circuit, I would not call it a disadvantage - the need for a constant supply of + 12V. Extended extra. wire on the left side and connected in parallel pin. 7 connector of the rear wiring harness (power supply for the interior lighting) or to Ш4.14 CHYa. The circuit is protected by a fuse. The consumed current is not more than 0.8 mA, which is not essential.
Reed switch placement
Rand the displacement of the magnet
As a result, two tasks were solved with one device:
The alarm clearly responds to the opening, the reed switch is hidden under rubber compressor and not subject mechanical impact, magnet in the lamp niche (reverse + PTF);
- the light in the trunk turns on when you open it (you can turn it off with the button on the ceiling if you don't need it).
It all started with the fact that after acquiring a VAZ 2106 car, I started having problems, like many owners of the classics, namely, they began to drain gasoline. Starting the car in the morning, I was surprised to find that the fuel gauge was at zero.
I tried to put different covers with a key and with a code, but they are easy and, it seems to me, without special efforts were hacked by those who poured gasoline with enviable regularity. Installation of an inexpensive alarm system with feedback the problem with the shock sensor was not solved, and it was decided to install an additional sensor on the gas tank flap so that the alarm would work immediately after opening.
As additional sensor the alarm switch was chosen (because the limit switches are not a reliable thing, they quickly oxidize and at the most crucial moment they may not work especially in the cold) because of its reliability. Firstly, the contacts of the reed switch are absolutely hermetic and are not afraid of moisture and frost. Secondly, there will be no spark (there is an opinion in the case of a limit switch) near the gas tank. I got a kit (reed switch + magnet) which is used in burglar alarm.
But such a reed switch will not suit us, because when a magnet is brought up, its contacts will be normally closed, but we need, on the contrary, normally open ones, in order to imitate the limit switch. There were only flip (universal) reed switches in the store, but they will suit us the same.
From the kit we will use only the magnet and the case. We bite off a single output at the reed switch so that it fits in the case, shorten and solder a piece of wire, preferably in silicone insulation, onto the remaining two contacts so that it does not crack in the cold, and isolate the place of soldering with heat shrink.
We assemble the case and we have a reliable sensor that will imitate the limit switch.
We check the performance of our design, for this we connect the multimeter to the sensor contacts, it should show a short circuit, and when the magnet is brought up, the circuit should open. All that remains now is to install the sensor. The magnet is attached to the gas tank hatch, I used epoxy glue (after degreasing and slightly cleaning the surface of the rough sandpaper), and the reed switch is above the gas tank neck. I connected the wires to the tailgate switch.
Now, when the hatch is opened, the alarm siren immediately goes off, which becomes a complete surprise for thieves. This system been used for 2 years and never failed and false positives.
A little about operation.
At first, after installing the sensor, I had to blow myself up at night to close the hatch cover, because when they tried to drain the gasoline, the alarm went off and the thieves quickly retreated leaving the hatch open, and the alarm could not be restored. The problem was solved by installing a small return spring on the hatch. After several unsuccessful attempts to drain the gas from my car lagged behind. This alarm paired with a lid combination lock on the neck of the gas tank reliable protection and not at all attractive for lovers of foreign gasoline.