One for the electronics experts me thinks ??

[paulham]

Or

[rodp]

Mmmm, like the flame thrower idea May have a detrimental effect on the alloy door panels though

Can't have a light beam as we have as many as 6 cars on the drive sometimes, also you would have to walk through it to get to the front door.

[Marky610]

Park it on a pressure plate? Truck moves=all hell brakes loose

[Radagast]

Claymore and a tripwire will do the job. You may need to install a mains fire hose to wash the muck off the walls afterwards.

[AirRifleSport]

Get in touch with the SAS and ask for volunteers to guard it... Make it as a challenge to them... See how long can a team of three men last, hidden away somewhere in your garden. There would be an annual winner and a the time lasted going to their hall of fame. If they should catch someone trying to steal it, (dead or alive) they would get 10 million pounds... Each!

[AirRifleSport]

I would go with Mark's idea though.

[sedstar]

we used to call them "james bond switches"...

you put a SWITCH where normally a wire runs from point A to point B.

armed wth this KNOWLEDGE? its a plan to...

1) spend a lot of time and energy sitting around dreaming up WHICH wire to install the switch to, will make it the most DEVLILISH thing that will render th vehicle undriveable. Be creative... any moron can find a disconnect to the battery terminal... now, WHAT about a SWITCH installed... to the negative or power lead, to the BRAIN BOX? eh?

after the early 80s, the brain box has to activate a relay, to turn on the fuel pump. AInt no car runnnign wthout a fuel pump...

2) pend an equal amount of time and energy getting DEVILISH about WHERE to install that switch. To hide it, yet, YOU know where it is... tech tip? you dont hav to locate the switc AT THE WIRE. you CUT the wire in the weird location, ad run 2 wires OUT TO the switch.

3) switch doesnt have to look like a switch, or, can be camoflaged right out in the open.

4) once you DO THIS, and have a weird switch disconnectinng the power to the brain box? You are now up agaist the "need to know"... you DO NOT eventually get lackadaisacal with the secret... IE, your brother in law is borrowing it, rings you up, "why wont it start"

"Oh thats right... you have to flick the switch or it wont start... its inside the interior dome light..." then HE goes and tells the funny story at the pub... next thing you know, every arsehole and his uncle in 3 counties, knows how to activate your "secret" theft prevention device.

=================================================

nothing in the world will stop a smart, and determined thief.

you know the people who build solid block buildings, and put bars and alarms on the few doors and windows, and armor them?

i can get inside in seconds... i just take a SLEDGEHAMMER to the 3-hold block wall... and i can crawl in. within seconds.

now... a car that wont start? nd thers no EASON for it no to start? Te danged KEYS are in the ignition, it simply wont start?

i do not have a way to ovrcome THAT... at least not quickly. It would take me QUITE SOME TIME to diagnose that little gem i described...

[rodp]

Mark, pressure plate would be visible (gravel drive, we run LR's and need to be able to remove oily mess now and again), then they just have to short the wires with a stapler The idea of a sensor is that it could be completely hidden, you're on the right track though Is there nothing used in industry that senses lumps of metal going past? Nothing used on conveyors to count items? I thought about the coil off a metal detector but don't know if they're meant to be permanently on?


Sedders me old mucker, you've never seen a series have you ? Brain ???? They hadn't invented brains, when series were made you boys were still wearing big hats, eating beans and riding horses after injuns
You can have all the isolators you want, it doesn't stop a tilt and slide backing up and having it away.

It needs something completely hidden that lets all hell loose when the vehicle is moved without permission. It also needs to not cost an arm and a leg, or at least one of them
So, ideally, a sensor with a range of three or four feet either inside the front of the house or set in the drive. That's what I'm thinking anyway, as always I'm open to ideas.

SAS would be a good idea and if this Government carry on the way they're going there'll be a few looking for jobs shortly, however, I don't think I can compete with an Arab oil Sheik for salary

[sunndog]

what about a magic eye then.....landy blocks beam, circuit broken....landy moves, circuit complete. alarm goes off

would have to hide the migic eye like

[phoenix]

Rod,
There are sensors (capacitive and inductive proximity) which detect metal and could operate an alarm when the metal moves. Unfortunately all those that I know anything about are very short range - 2-3 inches max.
One possibility might be RFID (radio frequency identification) tags
This is like the tags they put on goods in a shop and which cause an alarm to go off if the tag is still on the goods when they leave the shop.
The tag could easily be hidden in the vehicle and the reader could be in the house.
I think the reader could be set up to check for the presence of the tag on a regular basis (say every minute) and if the tag doesn't respond then an alrm could be triggered.
Let me make it clear, I don't have any hands on experience with RFID, but it might be worth further investigation.
BTW I checked E bay for "long range metal detectors" and every one advertised is a scam - just like those "bomb detectors" which don't work but were sold to Iraq for a lot of money by a British guy who, I'm glad to say, is now serving time fgor his nefarious activities.

Cheers

Bruce