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Has anyone ever gotten SHOCKED from a 12v wire in a car?? It happened to me.. While installing a HU in a Nissan Sentra, I recieved a nice jolt from the vehicle's accessory wire. It happened while holding the bare wire when I used my other hand to turn the key to the acc. position. The shocking phenomenon was later confirmed by three of my co-workers. (it was very amusing!!). Can anyone explain what was happening?? Incidentally, my digital multimeter was connected to the same wire and was reading 12v dc.( I didn't check it for ac though).
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I asked a dei tech support guy that question once. Customer was getting shocked when they put there key in the switch!! He said it sounded like something in the car discharging ac energy (ignition coil, etc). Maybe that is kinda what was going on(maybe there is a cap on that circuit and it is discharging to ground through you. Just my take, Im not really sure.
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hccaguy: Has anyone ever gotten SHOCKED from a 12v wire in a car??
Yes, i've gotten shocked from 12v.
Can anyone explain what was happening??
You were basically shorting the acc. wire to ground. Acc. wire to you, to the key in the ignition which was grounded. The juice came from either electronic devices connected to the acc. wire draining back to you, or from turning the key on. AC was not involved.
ea1, believe it or not, the customer's car wasn't grounded to earth ground properly. Cars discharge static electricity through their tires. Some tires have higher impeadance than others. Hondas had a problem like this a few years back.
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i seen josh mertzig get zaped by a 196 volts ac while working on hisblazer this past weekend.It was pretty funny
------------------ Anthony Lloyd Team RPM Speed & Custom/ Radio Active Sound Performance Audio Racing Image Dynamics Sound Pressure Team Team U.S. Amps Stroker she'll like it better than being shocked CVMCTHS.
Posts: 3225 | From: Loves Park , Ill | Registered: May 1999
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University level physics lab... I hook up 2 power supplies in parallel and proceed to uae a pair of transformers to jump up our 12 volts to 480V. (my lab prof hated me ) I thought it was neat that you could feel the 60Hz hum through the test leads if you held them both in one hand. I turned to a partner and told him to try.
He grabbed the bare ends.....
He was mad.
------------------ Blow your mind - PORT your box!
quote:Originally posted by ea1: He said it sounded like something in the car discharging ac energy (ignition coil, etc).
The only thing you could really feel is coilcurrent being stopped. Especially relays have zapped me dozens of times (I'm not a carefull enough person...). If you run a DC current through a coil, a magnetic field is created. If you stop this current flowing, the magnetic field will collaps and cause a reverse voltage. This voltage can reach hundreds of volts and would explain the 'zap' you got. Ever hear of using diodes with a relay ??? The diode is used to short this voltage before it can reak havoc in your headunit or other equipment.
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I have to agree with R-P. The only time i've gotten a jolt from a 12 volt system is when relays are involved and the accessory line could be in parallel with a few.
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