Re: Car alarm that goes off when in a certain distance

[Frank Olson <Use_the_email_links@xxxxxxxxxxxxxxxxxxxxxx>]

Karl Magnus wrote:
>
>>>>  Hi,
>>>> Hope someone can help with this.
>>>> I would like to be able to set up a alarm on a car. It would only go
>>>> off if the car got in certain distance of some point, say 100 feet.
>>>>
>>>> In other words if the car drove up to where I work my alarm would
>>>> sound that the car is nearby.
>
>
> I have done this. I used a ITI transmitter (long life) and a Mercury
> switch attached to the input terminals. Dip the transmitter (once
> programmed in to your system) in that stuff they sell to coat your tool
> handles for protection. Then mount it on the "ledge" underneath the
> front t bumper or somewhere else. As a call pulls up and slows
> down/parks, the mercury will shift back and forth causing the
> transmitter to transmit. On the ITI stuff, you can put it in group 25
> (older panels) and it should be "non-supervised". This will cause the
> alarm to chime anytime the car pulls up withing range.
>
> KM


Excellent solution, Karl.  I didn't realize they still sold mercury
switches (what with the environmental concerns and all).  I suppose any
good movement detection switch would work (and automotive types would be
weather-proof too).  While I'm thinking about this we should also warn
the OP that you can't guarantee the range on the transmitter will always
be optimal.  I'm not sure what to suggest about that as I've often found
the position of the transmitter can affect the signal strength/range.