[zzzzjones (OP)]

I am looking for an electronic cut-out switch that works on a car. The activation button is hidden, sometimes under the carpet. The car will start and operate normally, but if the hidden cut-out switch is not triggered, then the engine will suddenly come to a halt in a predetermined time (eg 20-60 seconds). The owner/driver will always know of the hidden switch and will trigger it within a few seconds of starting the car. A thief, however, would likely just assume since he/she can hot wire the vehicle and take off, that there will be no problem. However, if the thief fails to trigger the hidden switch, then the car will die and come to a halt less than a minute. Any one know how to build such a device... what parts needed?   

[Don_1]

I would say such a device would not be a good idea. Although it may be that the thief would more than likely abandon the car after it's engine has cut out in such a way, it could prove to be hazardous to other road users.

I would not be surprised to find such a device would be illegal.

[Nizzle]

Yep, there are better alternatives.
There are tracking devices that are installed in cars.
If your car is stolen, you'll have a gps monitoring thingy that tracks your car. You call the cops, give them your gps monitoring thingy and they'll go get the bad guy

[RD]

http://www.thenakedscientists.com/forum/index.php?topic=20459.0

[lyner]

A simple hidden switch could solve the problem or a tap in the fuel line. Anything non-standard would put off a theif but the last thing you want to do is to annoy the thief. He would run it into a wall in frustration if it suddenly conked out.

[coquina.rocks]

Instead, make a device that will lock a potential thief inside the car the minute he tries to start the engine, and set off an alarm - "to catch a thief". []

[Geezer]

Instead, make a device that will lock a potential thief inside the car the minute he tries to start the engine, and set off an alarm - "to catch a thief". []

Yeah! Then it opens a valve so that the car starts filling up with foul smelling smoke. At the same time a pre-recorded message announces;

"The air in this vehicle is now being replaced with a deadly nerve gas. Asatlavista Baby."

or would that be a bit too strong?

[Nizzle]

That'd be murder []

But if you want to catch a thief, you better have bars coming out of your car in front of all the windows, or have the air in the vehicle replaced by sleeping gas.

[Geezer]

Not murder. The smoke would be quite harmless. But I suppose the perp might die of fright.

[lyner]

But all/ most of that is illegal.

[Geezer]

But all/ most of that is illegal.

Not where I live!  []

(that statement may not be entirely accurate - BTW, the police in the US do use "bait cars" to catch car thieves. The police can turn off the engine by remote control, and I'm fairly sure they can lock the doors too. If the police can do something like that, I think US law would permit me to take some similar steps to protect my property. Nerve gas would of course be a no-no, except in Texas.)

[JimBob]

... but the last thing you want to do is to annoy the thief. He would run it into a wall in frustration if it suddenly conked out.

Ah, question, please. How could the thief run it into a wall if it were not running?? I would think that if the car were rolling to a stop, the thief would prefer to get out of the vehicle without injury to themselves.  []

And yep, we use never gas - controls the 23 foot long rattlesnakes. Pump it down their hide-holes.

[Geezer]

Kindly 'splain "Never Gas".

[JimBob]

The never show their heads again, - nuf said. (It does work on the nervous system somehow. 'Splain that.)

[Geezer]

The never show their heads again, - nuf said. (It does work on the nervous system somehow. 'Splain that.)

I will.

Splumgelfegitopiaconstramitism.

[Don_1]

... but the last thing you want to do is to annoy the thief. He would run it into a wall in frustration if it suddenly conked out.

Ah, question, please. How could the thief run it into a wall if it were not running?? I would think that if the car were rolling to a stop, the thief would prefer to get out of the vehicle without injury to themselves. 

If some 'orrible little nurd nicks your motor, he is bound to make of at high speed, 'pedal to the metal' and all that. Since most cars can get to 60 MPH in a few seconds, your prized set of wheels could be doing a fair speed when the engine cut out activates. This would mean a loss of power steering and servo braking. Chummy wont be too particular about how or where he brings the car to a halt, so he can do a runner.

....... BTW, the police in the US do use "bait cars" to catch car thieves. The police can turn off the engine by remote control, and I'm fairly sure they can lock the doors too. If the police can do something like that, I think US law would permit me to take some similar steps to protect my property. Nerve gas would of course be a no-no, except in Texas.)

It is true that the police use 'bait cars' which can be remotely immobilised and the doors locked.  But the point is, they can be remotely immobilised, by a police officer who can judge where and when to activate the device, without putting the general public at risk.

[peppercorn]

http://www.thenakedscientists.com/forum/index.php?topic=20459.0

Oooh - that's one of my topics... This question seem more than a little similar, doesn't it?


I have continued to give it occasional consideration and I reckon the most realistic 'homebrew' immobiliser (for older single coil cars) involves putting the coil in a lockable metal box.

There is a hole is in the top just big enough for the HT lead to pass through & another for a small cable bundle to pass through.

The security element relies on having a number of fake & interchangeably connected wires that run from the box the a head-unit on the dash.

The key-fob sized head unit (with handy start engine button) would plug into the dash & simply rely on having the correct two wires connect inside the fob (say the breaker side).  You the take the fob away, instead of a key.

Obviously the thief may be able to work this out with a meter, but would he bother? I think not!

A slightly more advanced design could incorporate a transistorised breaker circuit (to save ya points) with electronic switching in the fob.

[RD]

"The air in this vehicle is now being replaced with a deadly nerve gas. Asatlavista Baby."

or would that be a bit too strong?

Not in South Africa ...

The Flame Blaster consists of a small, 3-liter container of petroleum gas, which is typically mounted in the trunk of the vehicle, and nozzles fitted under the front doors of the vehicle. The electronic ignition system of the Flame Buster is activated by pushing a button (located near the foot pedals), resulting in three-meter long jets of burning liquid petroleum being thrown from both sides of the vehicle. The Blaster can be used five times before the gasoline tank needs to be refilled. The intensity of the blast can be set to individual' motorists' preference and the flames have been shown to cause no paint or other damage to the car. The system is not intended to kill assailants but rather to distract them and afford motorists the chance to escape a potentially life-threatening situation. The biggest drawback of the Flame Blaster is its high risk of injuring innocent passersby. Still, the device is completely legal when used for purposes of self-defense.

http://transportation.frost.com

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[syhprum]

Carry dogs around so that the car really stinks, a had a work colleague who had his car stolen and rapidly abandoned as it was unsalable.
I find security devices as often as not backfire on the owner, it would be me that gets locked in or the engine would cut just as I turned onto the motorway.