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-   -   Central locking versus remote locking (https://www.team-bhp.com/forum/technical-stuff/18199-central-locking-versus-remote-locking.html)

Would like to know more about what the difference\similarity is between remote & central locking mechanisms!!! I will be taking delivery of a 1.2 ELX Palio next week, & it has central locking as a standard fitment, but I just dint know enough to differentiate between the two systems.

As I understand and was told when I got my Safari 4x4 in 1998, the central locking means if you lock the door of the driver side by the key from outside or from inside then all the four doors and the boot door gets locked. And inversely if you open then all doors open.

Remote locking is a bit advanced version of this wherein you don't have to turn the key to lock or unlock. In this a small console is fitted inside the car and you get a remote key chain with buttons for locking and uncloking. You press the button for locking and the all the doors lock and similarly unlock as well. It works on infrared principle if I am not wrong and operates comfortable from a distance of 100 meters.

What ever GD1418 mentioned is correct and with a small correction, It works on Radio frequency 27 MHz (official keyless entry frequency)

Also, in a car with central locking feature, the fitment is easy by wiring this console only to the driver's door lock solenoid, otherwise you have to install solenoids on all the door locks.

Thanks DRC for correcting and enlightening..much appreciated.

The Daewoo Cielo/Nexia had central locking system without a radio remote control.

Central locking
The two rear doors and the front passenger door
had electric motor-driven rack-and-pinion actuators (not mere solenoids) on their doorlock rods.

Each actuator consisted of an electric motor turning a pinion that wound up or down a rack, locking or unlocking its own door alone.

The driver's door had no motor-driven rack-and-pinion actuator -- only a simple SPDT (single-pole-double-throw) switch to activate or reverse the other three doorlock motors.

Remote locking
To enhance this set-up to remote locking, you had to add a motorized rack and pinion actuator for the driver's doorlock rod too.

This actuator would be energized by power-transistors driven by the radio receiver circuit.

Aftermarket suppliers like Autocop provided

1. the radio transmitter
2. receiving circuit plus
3. this additional actuator for the driver's door.

By radio-controlling the driver's door rack-n-pinion actuator, you could lock/unlock all passenger cabin doors.

Hope this clarifies the difference between central locking and remote locking.

Postscript
Inspired by Daimler-Benz’s “Keyless Go” product on the 2000 Mercedes S-class, I had wired my Daewoo Nexia with a Philips "Mifare" contactless SmartCard reader instead of the Autocop analog radio circuits. With the Schlumberger contactless smart-cards, I could separately unlock the passenger cabin and the trunk of my Nexia. Being able to remotely pop-open the trunk was a great convenience.

The idea was to have a contactless SmartCard peripheral interfaced to an in-car embedded computer to automatically secure the car. Back in 2000, my prototype could autonomously wind-up and wind-down the windows and control the central locking system of my new 2000 model Daewoo Nexia.

My current Baleno VXi has a mechanical cable-release for the trunk, instead of the Cielo/Nexia's electric release, so it's a little more complex to remotely unlock the trunk.:mad:

Ram

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Off topic:
I used a Philips MiFare ISO 14443A contactless SmartCard peripheral. It fit beautifully into an autorickshaw taillamp lens which I used as the casing. The assembly was fixed on the rear parcel shelf, flush with the rear quarter window.

The main Atmel microcontroller based motherboard was mounted in a polypropylene bread-box in the trunk.

A Schlumberger contactless smart-card presented within five inches of the rear quarter window from outside, unlocked the car and disabled the ignition immobilizer. My carputer also recorded timestamps of when the car was last used. Had to replace the driver's doorlock inside lever, with a motorized one from Autocop.

Used another Schlumberger contactless smart-card with a different digital signature-id to unlock the Nexia's trunk.

The system would also automatically windup the windows and lock the car, if the car was left unsecured for some (programmable amount of) time. One early issue that bugged me, was that after 8-hours in the hot sun, the car's battery voltage would drop below the design 11.5 V.

In summary, it was a hugely successful project, but SmartCard peripheral costs in 2000-2001 prevented me from making it a viable commercial product for India.

Very very interesting. That was then in 2000-01. what about now?

surprising that no one mentioned the alarm system that comes with the remote locking system. After the car has been locked using the remote, it can be re-opened only with the remote. if a miscreant tries to open the car with a key, then all hell will break loose. or even if he gains entry into the car & tries to start, there are alarms that go off & some even have engine immobilisers. :)

An:OT comment.

Recently there were emails going around that you can open your remote locked car via a cell phone and spare remote located anywhere if you've lost the keys or something. Well, its true.

All you need to do is take the call on your cell phone, let the other person put the remote to their cell and press the unlock button. Your cell needs to be near your front door / hood. It Pops open!clap:

Its tried and tested! A very neat and handy way to get out of the lost-key situations!

Yes. It is indeed true. One of my friends tried it out on his car and it really worked !

did work here as well. But something which i dont like remote lockin system as ive read in the newspapers quiet some time ago that family got burned up in the car itself while trying to unlock. the car wouldnt unlock at all and they even tried to break the glass but was too late.... i rather prefer central lock ....... no offence to any remote locking system users here.

Even if the car is remote locked and you are inside, the doors can still be opened by shifting the lock button to unlock position. The only minus point would be that by opening in such mode the alarm would go off. But who cares if your life is at stake!!!

Secondly, while sitting inside if the car catches fire, the sheer terror clouds the brain and in the panic nothing seems to work.. In Benares in the parking of Taj Ganges I parked my esteem and got out and locked it with remote lock forgetting that my wife too was sitting in. When she tried to open the door, it wouldn't and she panicked and started screaming and banging the windows. All she could have done was to roll down the windows as they were not power windows and called me. Fortunately the parking guard saw her and alerted me and I opened the car.

My point is that prescence of mind is very important in dicey situations..

OT but I dare to imagine what consequences this had considering it was your wife!;)

Ah..! the consequences...Can't write them here....To relive that itself is a nightmare...(and my wife is not reading this)....:)

man, i hope you had the presence of mind after getting yourself into that dicey situation !
BTW, did you know that there are better ways of getting rid of your wife ??lol:

man gd1418, you got some guts to do that to your wife....