Disable Prius with a magnet??

Well, here's an old article about students riding around in a Prius checking for magnetic fields... and it includes the word "disable" in a different paragraph, but that's about as close as I could find googling around...

http://www.gazettetimes.com/articles/2004/...ty/friloc01.txt

- Bob R.

 

The only things I can think of (and this would be pure speculation) is that you can fool some kind of safety-lockout sensor with a strategically placed magnet, hold a relay open or closed likewise, or fry the smart key with a sufficiently strong magnetic field. But such prankery would be applicable to any modern car, not just the Prius.

As a completely off-topic aside, it reminds me of a prank that you could do on really old radios, the kind with mechanical presets. Given access to the stereo, you could set all the presets to annoying stations and then carefully remove the string from the internal pulley system, causing the poor victim to be forced to listen to your selections.

- Bob R.

 

Maybe my physics is very rusty now, but could someone remind me how a magnet that generates static magnetic field could possible affect electronic circuitry? Dynamic magnetic field could induce electric field on metal, therefore, induce current, therefore affect electronics. But not a magnet that generates static magnetic field.

A large speaker placed next to a CRT TV could distort the TV picture. However, that is because the CRT employs electron beam which is controlled by a changing electric field which could be affected by the static magnetic field. (This actually happened to me once.)

The static magnet could probably affect the wireless devices. Other than that, I fail to see any possibility. Anyone? BTW, the EM wave generated by a nucear weapon or an EM bomb are not static EM wave.

Correct me if I am wrong here. It is time to review my EM physics.

 

a strong enough magnet can disable nearly any car i suppose. magnetic fields alternating opposition and attraction is how the EV works.

personally i think the story goes next to the "electrocution in an accident"

 

nah. can't think of anything that would be affected enough by some magnet to disable the car.

if you were able to place a magnet on the door, without the owner noticing, you could MAYBE disable smartkey function. maybe.

yep, more hybrid myths every day it seems

 

Sure one could.
You know those big crane things they have in junk yards? Slap one of those on the top, lift.....it ain't going any where.

 

How about the EMP from the detonation of a small thermonuclear device

 

A magnet's "static" electric field is only "static" if the magnet is not moving relative to the device measuring the field.

Moving a magnet along a conductor induces electron flow.

So yeah... the kids could haul a 10 ton electro magnet (the kind used in scrap yards) and disable your Prius by lifting it off the ground.

Of course... they will do that to ANY other car also

The BS rises so fast on the Internet, you need wings to stay above it!

 

I think ANY new car could be disabled by a magnet. All cars I know of have tons of relays, including one for the fuelpump or injection system. Stategically placing a large enough magnet next to the right relay could possibly keep it from closing the contacts. But, thats the only thing I can think of. :blink:

 

that is exactly what I was thinking and if you could do it to a Prius you could do it to a Hummer as well also a Ford or MerChryk or Fiat or anyother vehicle with EFI.

 

Urban legend. If they can't provide a pointer to details of the technique just blow them off.

 

I'm with richard

*** URBAN LEGEND ***

 

You throw the magnet as hard as you can and knock out the driver.

 

doesn't that huge battery pack create some sort of magnetic field anyways? i remember a friend testing a crappy compass in the hills.. and since it was hills.. i guess... it kept pointing towards my battery pack... so a little more magnatizm <-- spell checke that if you like. lol shouldn't hurt our car.

 

Ar-ar!!!

 

Yeah, that is where I was going too. But EMP would disable any vehicle because it would render the spark system on gasoline vehicles useless. It would also really mess up onboard computers on vehicles making most of them totally useless also.

 

You're not too far off the mark. A static magnetic field has little effect on most electronics, wireless devices included. There are several possible problem areas, but most would need a fairly large field, which is hard to get with a small permanent magnet. Here are the ones I can think of right off the top of my head:

1) Placing a magnet involves moving the magnet, so we have a time-varying magnetic field. This will induce a voltage in any conductors cut by the field, but only while the magnet is being moved.

2) The magnetic field could acuate or trip mechanical relays or hall-effect sensors.

3) A magnetic field could saturate iron cored inductors and transformers.

4) A magnetic field will induce a hall-effect in semiconductors, causing the current carriers to seperate. In extream cases this can cause integrated circuits to fail.

5) If you had a big enough field, you could saturate the iron in the motor-gensets (MG1 & MG2), this would stop them dead. Mind you, you need a BIG magnetic field to do this, but we used to see this routinely back when I was designing MRI scanners, which have HUGH magnetic fields.

All that said, you are never going to find a big enough magnet to cause any problems, unless it was stuck right onto a sensor or relay. It's a fun question, at any rate.

Tom