Can anyone explain how Proximity cards work.

[killivolt]

Does it have a processor and how does it get the information from the cards ?

RF/sonar ? what.


kv

 

[fingaz]

Hi KV

I believe that proximity cards work on the principle of RFID. A passive chip is embedded in the card, when you hold it near to the 'antenna', the antenna sends a pulse to the chip, this powers it so it cand send back it's 'response'. they use the same system for transponder keys in modern cars.

see here for a basic description of how it works : http://www.technovelgy.com/ct/Technology-Article.asp?ArtNum=2

Hope this helps

 

[Mikebits]

Look here also...
https://www.electro-tech-online.com/custompdfs/2008/09/doc2056.pdf

 

[killivolt]

Thanks for your help. (mikebits)(fingaz)


kv

 

[killivolt]

256 limit ?

While reading this it saying that the maximum on the non powered RFID is 256 bytes. Is this the limit or am I reading something wrong ?

kv

 

[killivolt]

Ok, Now if a person were to attempt making a Card that has the ability to have a power source a small battery or something.

Could you make it so that it used IR instead of RF and yet keep it at the same size ?

kv

 

[rezer]

While reading this it saying that the maximum on the non powered RFID is 256 bytes. Is this the limit or am I reading something wrong ?

kv

That would be the memory limit of the card.

 

[jpanhalt]

Ok, Now if a person were to attempt making a Card that has the ability to have a power source a small battery or something.

Could you make it so that it used IR instead of RF and yet keep it at the same size ?

kv

Possibly, but but getting the battery and IR to be small and last a decent amount of time would be difficult.

Most important, it would not be proximity so much as line of sight.

In my experience, proximity cards are non-intrusive. That is, you sign onto the computer. If it detects you have the proper security from your card, which is often like a name/ID tag on your person, everything goes smoothly. The link is broken when you leave the vicinity by more than a meter or so. In contrast, having to take an IR card, point it at the computer, and keep it in communication would be more intrusive. You might also forget about it and leave it at the computer.

John

 

[killivolt]

Possibly, but but getting the battery and IR to be small and last a decent amount of time would be difficult.

Most important, it would not be proximity so much as line of sight.

In my experience, proximity cards are non-intrusive. That is, you sign onto the computer. If it detects you have the proper security from your card, which is often like a name/ID tag on your person, everything goes smoothly. The link is broken when you leave the vicinity by more than a meter or so. In contrast, having to take an IR card, point it at the computer, and keep it in communication would be more intrusive. You might also forget about it and leave it at the computer.

John

So, overall you would have a card that could ultimately do the same thing.

The hole electronic package is the same or similar except (Battery + IR emitter) instead of RF.

It would look the same except for those most apparent differences. (Bat/IR)

In this case intrusive - non intrusive not a problem. Line of sight not a problem.

Thanks rezer & John.


kv

 

[rezer]

So, overall you would have a card that could ultimately do the same thing.

The hole electronic package is the same or similar except (Battery + IR emitter) instead of RF.

It would look the same except for those most apparent differences. (Bat/IR)

In this case intrusive - non intrusive not a problem. Line of sight not a problem.

Thanks rezer & John.


kv

Yes, I understand what John is saying. However, this would work pretty well as a point-of-entry device.

 

[killivolt]

Not sure if it will work yet.

Yes, I understand what John is saying. However, this would work pretty well as a point-of-entry device.

Are you agreeing with my Deduction. That size and all would be the same ?

kv

Edit : I have wiki an image of a card. You can see the processor with just the antenna swirling around it pretty cool stuff.

I see now it can Maintain the same physical size.

 

[rezer]

Are you agreeing with my Deduction. That size and all would be the same ?

kv

Edit : I have wiki an image of a card. You can see the processor with just the antenna swirling around it pretty cool stuff.

I see now it can Maintain the same physical size.

I feel you can keep the same footprint of the card, but it will probably be a little thick due to the battery. Coin lithium is what I'm thinking.

 

[killivolt]

I feel you can keep the same footprint of the card, but it will probably be a little thick due to the battery. Coin lithium is what I'm thinking.

I was thinking a one shot and solar cell backup to charge it or even have a usb insertable ?

Thanks rezer


kv