R.F. driveway alarm idea.

R

Russell Griffiths

Guest
Greetings.
I would like some comments on this idea (please keep it nice).

I am looking into various types of sensors for a driveway alarm on
a farm.
PIR, Infrared beam etc.

Could it be possible to place some kind of r.f. transmitter on one side of
a driveway and a receiver on the other side to detect a vehicle.

Maybe a vertical loop on each side of the driveway.

A passing vehicle might block some of the transmitters signal reaching
the receiver.

Thanks,
Russell Griffiths.
 
On 18 Oct 2004 22:25:09 -0700, rg26ce1991@hotmail.com (Russell Griffiths) wrote:

Greetings.
I would like some comments on this idea (please keep it nice).

I am looking into various types of sensors for a driveway alarm on
a farm.
PIR, Infrared beam etc.

Could it be possible to place some kind of r.f. transmitter on one side of
a driveway and a receiver on the other side to detect a vehicle.

Maybe a vertical loop on each side of the driveway.

A passing vehicle might block some of the transmitters signal reaching
the receiver.
Click to expand...
First up, think of your power budget for the system, and how you send the hit to
big daddy. Some of these are thirsty, but all are workable.

If you are looking for vehicles (not pedestrians or stock) and able to dig up
the driveway (I'm hoping it's a typical garvel/earth farmer's loooong driveway)
then I'd be inclined to try a couple of buried loops with coupling dependent on
the amount of metal above - similar to traffic light systems.

Disadvantage - you have to dig it in. Advantages? No above-ground loops/beam
equipment for people to frig around with. It can be an all_below_ground system.
 
"Russell Griffiths" <rg26ce1991@hotmail.com> wrote in message
news:13cdb672.0410182125.634abc9b@posting.google.com...
Greetings.
I would like some comments on this idea (please keep it nice).

I am looking into various types of sensors for a driveway alarm on
a farm.
PIR, Infrared beam etc.

Could it be possible to place some kind of r.f. transmitter on one side of
a driveway and a receiver on the other side to detect a vehicle.

Maybe a vertical loop on each side of the driveway.

A passing vehicle might block some of the transmitters signal reaching
the receiver.

Thanks,
Russell Griffiths.
Click to expand...
Why use RF like this? It's always possible that the RF won't be totally
blocked by the vehicle if there's signal bouncing around all over the place.
Why not use an IR beam like in shops? Certainly cheaper, and if you put it
at the gate with a grate then cattle shouldn't be able to trigger it.

Ken
 
"Ken Taylor" <ken123@xtra.co.nz> wrote in message
news:2tl8ubF2248t9U1@uni-berlin.de...
"Russell Griffiths" <rg26ce1991@hotmail.com> wrote in message
news:13cdb672.0410182125.634abc9b@posting.google.com...
Greetings.
I would like some comments on this idea (please keep it nice).

I am looking into various types of sensors for a driveway alarm on
a farm.
PIR, Infrared beam etc.

Could it be possible to place some kind of r.f. transmitter on one side
of
a driveway and a receiver on the other side to detect a vehicle.

Maybe a vertical loop on each side of the driveway.

A passing vehicle might block some of the transmitters signal reaching
the receiver.

Thanks,
Russell Griffiths.

Why use RF like this? It's always possible that the RF won't be totally
blocked by the vehicle if there's signal bouncing around all over the
place.
Why not use an IR beam like in shops? Certainly cheaper, and if you put it
at the gate with a grate then cattle shouldn't be able to trigger it.

Ken
Click to expand...
Further to this;

If you are some distance form the house, you can use the output of a
lightbeam to trigger the alert call on some of the Electraphone UHF radios,
and have this call your base station at the house. I know the TX4000 and
TX4200 series Electraphones do this straight out of the box. Only thing you
need to do is get a tech to change the alert frequency on the UHF radio (I
think the default is to call CH 22 or 23). The radio sits asleep unless the
light-beam is broken, makes the alert code 3 times, and then goes back to
sleep.
A solar panel charging a battery, and the light-beam and UHF running off the
battery, and you are set!

Just a thought, but pretty simple setup.

Cheers,

Rod.......Out Back
 
On 18 Oct 2004 22:25:09 -0700, rg26ce1991@hotmail.com (Russell
Griffiths) wrote:

Greetings.
I would like some comments on this idea (please keep it nice).

I am looking into various types of sensors for a driveway alarm on
a farm.
PIR, Infrared beam etc.
Click to expand...
Don't know if you can get them in long range for a farm, but get a
standard wireless doorbell and remove the button,replace with a reed
switch on the gate - it's done.
 
Russell there is/was a product that does this and is specifically aimed at
agricultural applications.

I found it a year or so back. Sorry I can't provide a product name or futher
info.

If I remember correctly it was a standalone unit which mounted on a star
picket or similar adjacent the track/road. It had a flat coil arrangement,
maybe 20cm x 20cm and detected the movement of the vehicle (a big lump of
magnetic material) as it was driven by. I think there was back to the
farmhouse RF alert link and maybe a camera option. It did not need external
power and may have had a solar option (for the pedantic ones among us, yes a
solar panel could be construed as external power!)

Good luck finding it, I did a quick google without luck.
rob
 
Thanks to all who replied.
Unfortunately, there is no gate to open, so the doorbell/reed switch cannot
be used.

I had considered the metal detector idea. There is a circuit in E.A. (06/99)
that might work.

I have not tried to find the unit you suggested yet Rob.

Thanks.
Russell Griffiths
 
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