Proximity sensor

[gizmo98]

Dear net community,
I would like to build a proximity sensor for a Motorhome that could trigger
an alarm in various ways.
What I want is to be able to set off an alarm inside the vehicle if it is
approached during the night.
PIRs wouldn't be any use because they may be set off by animals. What I was
thinking of was something that would sense the presence of a body at about
chest level, but not ground level, around the perimeter of the vehicle. If
it were possible to switch this circuit so that at other times the alarm
would be triggered if the door handles were operated that would be a bonus.
The output of this would also need to be switchable between a small buzzer
type of warning device and a loud siren depending on how the circuit was
set. The working voltage would be 12v dc.

I have to say now that my knowledge of electronics is basic although I do
have experience. Any help with either a circuit diagram, suggestions as to
how I might obtain one or any books that may be of help would be most
welcome.

Regards
Steve
England

 

[Russell Powell]

Why not scare off the animals? True story: A friend of mine
returned to his lake house in Texas during the summer. The cabin
remained hot although the AC has been on for sometime. Upon
investigation, he found a goat and two dogs laying under the house.
The goat had chewed the the air duct under the house and the three
animals were laying next to the torn open duct to keep cool!

Now, back to your question.....
You could mount IR beams (like those used in garage door openers
to detect if something is blocking the door path) at chest level. You can
build a few brackets to mount onto the corners of the motorhome - just
inches away from all sides - running across windows and door too.
This may be closer proximity than you're looking for but should only
trigger if someone is actually that close to the window or door.



--
sincerely,

Russell Powell

Artisan Components
SR. FAE - U.S. Central
rpowell@artisan.com
469-438-6589





"gizmo98" <gizmo98@btopenworld.com> wrote in message
news:blhq79$p97$1@titan.btinternet.com...

Dear net community,
I would like to build a proximity sensor for a Motorhome that could
trigger
an alarm in various ways.
What I want is to be able to set off an alarm inside the vehicle if it is
approached during the night.
PIRs wouldn't be any use because they may be set off by animals. What I
was
thinking of was something that would sense the presence of a body at about
chest level, but not ground level, around the perimeter of the vehicle. If
it were possible to switch this circuit so that at other times the alarm
would be triggered if the door handles were operated that would be a
bonus.
The output of this would also need to be switchable between a small buzzer
type of warning device and a loud siren depending on how the circuit was
set. The working voltage would be 12v dc.

I have to say now that my knowledge of electronics is basic although I do
have experience. Any help with either a circuit diagram, suggestions as to
how I might obtain one or any books that may be of help would be most
welcome.

Regards
Steve
England

 

[tim kettring]

You can also use black electricians tape on the inside bottom of a PIR
, the pros do it all the time for pet-owners , it is called a "
pet-alley "

tim

"gizmo98" <gizmo98@btopenworld.com> wrote in message news:<blhq79$p97$1@titan.btinternet.com>...

Dear net community,
I would like to build a proximity sensor for a Motorhome that could trigger
an alarm in various ways.
What I want is to be able to set off an alarm inside the vehicle if it is
approached during the night.
PIRs wouldn't be any use because they may be set off by animals. What I was
thinking of was something that would sense the presence of a body at about
chest level, but not ground level, around the perimeter of the vehicle. If
it were possible to switch this circuit so that at other times the alarm
would be triggered if the door handles were operated that would be a bonus.
The output of this would also need to be switchable between a small buzzer
type of warning device and a loud siren depending on how the circuit was
set. The working voltage would be 12v dc.

I have to say now that my knowledge of electronics is basic although I do
have experience. Any help with either a circuit diagram, suggestions as to
how I might obtain one or any books that may be of help would be most
welcome.

Regards
Steve
England

 

[GMdude]

Russell,

That was an excellent suggestion (IR), but there is one factor that you
might have missed,... Mother Nature. Not animals, but adverse weather
conditions. I'm not an electronics tech., per say, but I'm familiar with
this type of system.

I'm an automotive tech that specializes in on-board computer
diagnostics, and electronic problems.

Let me explain. If a single water droplet gets on the lens of the
emitter or reflector on our garage doors, the doors won't close. The beam
has been broken (reflected elsewhere). I have to go and wipe them dry every
time this happens.

Even if you fabricated hoods for the emitter and reflector, a heavy rain
passing through the beam, would cause a false trigger.

GMdude

P.S. I'm not knocking your suggestion. It was very good, but I think the IR
stuff works better indoors.

 

[bj]

HI RUSSELL
Thanks for your input
Its been 30 years or so since I studied/had anything to do with electronics
but I'm using this IR project to get me back in the swing of things
however I don't understand how your gararage doors have anything to do with
my project.(emitter,reflector, garage door closing ???) I suspect your
system is using some form of coded signals whereas I'm just trying to
controll raw infra red
PS if anyone knows of any groups dealing with playing about with underwater
cameras please let me know

BJ
"GMdude" <none@there.com> wrote in message
news:%Xilb.199297$%h1.192773@sccrnsc02...

Russell,

That was an excellent suggestion (IR), but there is one factor that
you
might have missed,... Mother Nature. Not animals, but adverse weather
conditions. I'm not an electronics tech., per say, but I'm familiar with
this type of system.

I'm an automotive tech that specializes in on-board computer
diagnostics, and electronic problems.

Let me explain. If a single water droplet gets on the lens of the
emitter or reflector on our garage doors, the doors won't close. The beam
has been broken (reflected elsewhere). I have to go and wipe them dry
every
time this happens.

Even if you fabricated hoods for the emitter and reflector, a heavy
rain
passing through the beam, would cause a false trigger.

GMdude

P.S. I'm not knocking your suggestion. It was very good, but I think the
IR
stuff works better indoors.