proximity device needed

[Phil in Melbourne]

The Toyota Prius has a key that does not need to be produced in order to get
into the car. You just have to have it in your pocket as you come close to
the drivers side door. It will let you in, and you can start the car (via
pushbutton) and go.

This is a great feature that I want to replicate for my house. I dont want
to fumble around for my keys so I want something that I can just have on my
key ring. Is there a kit that I can buy that has this functionality?

I have seen these clips for PC computers too. They lock your PC if you go
further than about 5m away from it. What is the operating principle for
these things?

I really dont want to be changing batteries often. I assume that the cheap
PC locking devices are constantly transmitting a low power signal, but I
assume that the Toyota Prius device is a lot more complicated and ingenious.

I cant seem to find much technical info on both products.

 

[David L. Jones]

On Jul 20, 2:16 pm, "Phil in Melbourne"
<philippawlow...@veryverywarmmail.com> wrote:

The Toyota Prius has a key that does not need to be produced in order to get
into the car. You just have to have it in your pocket as you come close to
the drivers side door. It will let you in, and you can start the car (via
pushbutton) and go.

This is a great feature that I want to replicate for my house. I dont want
to fumble around for my keys so I want something that I can just have on my
key ring. Is there a kit that I can buy that has this functionality?

I have seen these clips for PC computers too. They lock your PC if you go
further than about 5m away from it. What is the operating principle for
these things?

I really dont want to be changing batteries often. I assume that the cheap
PC locking devices are constantly transmitting a low power signal, but I
assume that the Toyota Prius device is a lot more complicated and ingenious.

I cant seem to find much technical info on both products.

Probably just an RFID tag of some sort. The tags are passive, getting
their power as they enter the RF field, so no batteries required.
My home alarm system supports RFID tag readers for arm/disarm and door
strikes etc, but I don't think the range is good enough to leave it in
your pocket.

Dave.

 

[Joe G (Home)]

"David L. Jones" <altzone@gmail.com> wrote in message
news:1184910048.064828.326470@d30g2000prg.googlegroups.com...

On Jul 20, 2:16 pm, "Phil in Melbourne"
philippawlow...@veryverywarmmail.com> wrote:
The Toyota Prius has a key that does not need to be produced in order to
get
into the car. You just have to have it in your pocket as you come close
to
the drivers side door. It will let you in, and you can start the car (via
pushbutton) and go.

Probably just an RFID tag of some sort. The tags are passive, getting
their power as they enter the RF field, so no batteries required.
My home alarm system supports RFID tag readers for arm/disarm and door
strikes etc, but I don't think the range is good enough to leave it in
your pocket.

Dave.

Close, It's RF + RFID called PKE (passive keyless entry) rather then RKE
(remote keyless entry).


With car's specifically - there are 2 parts to the design challenge
a) Remote device that uses RFID receiver and RF transmitter.......
using minimal power so the key remote device has 2~3 years battery usage
be) Car RFID transmitter and RF receiver ... using minimal power so the car
battery doesn't go flat.


For your requirement ..... a long range RFID reader connected to the house
power and passive RFID tags (no batteries required).
**** The problem is long range RFID readers are expensive.

When I mean
i) Expensive ==> $600 +
ii) Long Range RFID reading ==> 700mm +


So long range RFID reader == expensive.


Joe