Now let's see the device diagram:
The transmitter is a conventional blocking oscillator. I used the KT315 transistor, but others can also be used. It is also possible to power the contactless key circuit from a 1.5 volt battery, but the higher the supply voltage, the greater the range. The only disadvantage of the circuit is that in order to start the key, it is necessary to close the base and collector for a short time. Key receiver. To begin with, we will assemble a simple receiver - a coil and an LED. Let's check if the SD works, you can go further.
Parts list for the device:
Transistor KT315 or any other
AA battery
Wire 0.1-0.6mm
The LED is 3V, but I also have 12V.
Let's move on to practical use contactless key schemes in everyday life:
Let's make some changes to the receiver:
- Schottky diode with low voltage drop
- Electrolytic capacitor 100uF
- Medium power transistor KT837, etc.
- Power supply, 12V battery can be used
- And most importantly - a relay that will control all connected loads.
Now a little about what this device will not work without - coils. The transmitter coils are wound on a pipe with a diameter of 5 cm, with a wire of 0.1-0.6 mm. The thicker the wire, the more current consumption and quality. L1 has 30 turns, L2 is half that - 15 turns. Attention! Coils L1 and L2 wind in the same direction. If you wind in a different direction, nothing will work!
The receiver coil is desirable to have as many turns as L1.
And here is the layout of the proximity key assembly:
If you assembled everything correctly, but the device does not turn on, try closing the collector and base several times - everything should work. During the experiments, I noticed that if you turn over the coil with the LED, it burns either brighter or dimmer. Here you can also demonstrate the principle of the ferrite:
It's a ferrite from a radio. The LED lights up as high as 15cm! Therefore, the receiver can be easily hidden in the case of any device, only the case should not be made of metal. I think you will definitely find a use for such a device. If not, then you can leave the LED, fix the transmitter, for example, under the table, and put the receiving coil on the table - you will also get a very funny device. And you can prank your friends, as I usually do)))
Discuss the article PROXIMITY KEY
In modern cars, in almost all the ignition key is not ordinary, it is the so-called chip - the key. What is it, how to change it. Recently, someone on the blog received a very interesting letter, I won’t retell it, but the person asks - how does the chip key work? The question seemed interesting to me and I decided to write an article on this topic ...
Indeed, there are no boards on the outside of the key, no contact groups, and so on, to apply it to any reader on the car. There is a key itself that is inserted into the keyhole, but it is not contact Group! So what is the working principle?
Going into technical details...
The car ignition lock has a certain frame that is connected directly to the immobilizer unit. When the ignition is turned on, the unit sends a pulse to this frame and switches to the reading mode, that is, it starts listening to the response from the chip key. In turn (from the impulse), the key chip is charged and starts transmitting the code sewn into it, transmits it to this immobilizer frame. The immobilizer frame accepts the code, and if everything is fine, it makes it possible to start the engine.
If just...
Submitting your work is very easy. Probably everyone (or many) have intercoms at the entrances. We approach, bring a special key fob, the intercom reads it and opens the door. This is an exaggerated example of a smart key and car immobilizer.
It should be noted that without this chip key, the immobilizer will not allow the car to start! It blocks various functions of the car:
- in some cars, the immobilizer is in the ignition lock itself and blocks various functions in the lock.
- others have an immobilizer built into dashboard and opens certain circuits of the car (for example, the fuel pump circuit)
- for the third, the immobilizer block is located in engine compartment, and with the help of amplifiers it can block both the lock and the chains at the same time.
As you can see, the device and the principle of operation of the chip key seem to be simple, but effective. However, now many alarms with auto start turn off regular immobilizer(particularly with additional key which fits in the dashboard of the car), I personally do not recommend doing this. Because the car becomes easier prey for car thieves.
And now small video article version
That's all, I think the article was interesting. Read our AUTO SITE
In modern vehicles equipped with new electronic keys (including contactless comfort access key fobs), there are problems with opening the car if the battery or accumulator is dead in the device, as well as with further starting the engine. After all, there is not always a battery at hand. Therefore, many car enthusiasts are faced with difficulties and do not know how to get into the car without the help of an electronic comfort access system. The thing is that many modern cars, instead of the keys we are used to, have electronic key fobs for opening and starting the car. What to do? We will try to tell you what to do and how to open a car,.
What happens if the battery in the electronic key fob runs out?
If your car is equipped with a comfort car access system, as well as a comfort engine start system, then your, with which the alarm vehicle, identifies you as the owner of the machine. When you approach the car, and the signal that the key fob transmits begins to be in the field of view of the car alarm, electronic system opens the car automatically, providing the owner with comfortable access to the salon without using a conventional key, or without pressing buttons on the alarm key fob.
When you get into the car, your electronic key fob continues to send an electronic signal to the car, telling the electronic alarm that you are the owner of the car. That is why you can start the car without problems using the stop-start button. But you have to pay for comfort with possible difficulties that any owner may face. modern car. For example, if a battery or accumulator runs out in your car remote control, then you will not only be able to get into the car interior, but also start the engine, since in this case your key stops sending without power, a signal is needed to the vehicle alarm unit.
As a rule, in this case, you will not be able or will not be able to start the engine. Even if you open the door, if the battery runs out of dashboard machine, you will see an icon telling you that the key was not found. Therefore, if your car does not have an ignition switch, then you will not start the car until you change the battery in the remote control.
In fact, fortunately, there are ways to open the car with a dead battery in the key, and even start the engine in some models. The fact is that most automakers have equipped electronic keys(key chains) with a hidden emergency key, with which you can not only open the door, but also start the engine of the car. But, really, not everything is so easy.
The biggest difficulty is that 11 automakers, having equipped electronic car key fobs with emergency keys, have hidden the key holes on the door handles. The worst thing in all car brands opening the car with the emergency key is different.
For example, brands such as Audi, BMW, Ford, General Motors, some Hyundai models, Jaguar, Kia, Lexus, VW and Volvo have hidden, hidden keyholes for an emergency key.
We offer you instructions for many cars, which will help you solve the problem if the battery in the car remote control runs out. With our guide, you will be able to open the car with the emergency key. Our publication series in coming time will include instructions for opening and starting the engine of the following brands:
Chrysler/Dodge/Jeep
Fisker
Ford/Lincoln
General Motors (Chevrolet/Cadillac/Buick)
Honda / Acura
Hyundai/Kia
Jaguar
Mazda
Nissan/Infiniti
Subaru
Volvo
VW / Audi
Today we are publishing the first instruction in a series of publications, which will tell you how to open the MINI, as well as how to start the engine without an electronic key fob, in case the battery is dead in it.
We open the BMW and Mini door if the battery in the key is dead.
In order to open the car door in the event of a low battery in the electronic key fob, we need an emergency spare iron key, which is hidden in your original car key fob. In order to get it out of the key fob, you must press the special button on the back of the key fob and slide the emergency key out of the remote control.
This integrated key can be used to open driver's door And . To open the door with this special key, you must insert it into a special hole, which is located at the bottom of the door handle of the front driver's door.
Attention!
Many new car models do not have open hidden emergency key locks. Automakers in Last year began to hide the key holes under the plastic door handles. Therefore, in order to open the door, you will have to damage the door handle by breaking off a piece of plastic.
For example, the BMW X5 since 2014 does not have an open technological hole to open the car with a special key.
In order to open the car door with a hidden key, you need to insert it into the hole (shown with an arrow in the picture) and press the door handle.
If your car has a hidden key lock, then put the key in the place indicated by the arrow in the picture and push the key up. The plastic hiding the key lock will pop off. Next, click on the key again and click on door handle- The door will open.
How to start the BMW and Mini engine if the key fob is dead?
Some BMW and Mini models, in order to start the engine, require the key fob to be inserted into a special socket, which is located next to the button. If the key fob battery is discharged, then by inserting it into the socket next to the stop-start button, the electronic system will recognize the electronic key fob.
If your BMW model and Mini does not require a key fob to be inserted into a special slot, then hold the key in the steering column area, as indicated by the arrow in the picture (see photo). Next, press the stop-start button for ten seconds while holding the brake pedal.
Note: If you failed to start the engine in the above way, then most likely brake system there may be residual pressure. In this case, a warning icon may appear on the dashboard.
In this case, try to restart the engine by depressing the brake pedal as hard as possible and pressing and holding the stop-start button for 10 seconds.
Attention!!! Press the pedal until the warning to press the brake pedal disappears on the instrument panel.
