# Ohms Law: Electrical Safety Question

S

#### SkeetX

Jan 1, 1970
0
I am just starting in electronics, and in a book I was reading it said
that a car spark plug could definatly give me a lethal dose of
electricity, even at 12 volts. I'm still having a little trouble
understanding it, but even if there are 50Amps of current behind that
plug, doesn't my body have enough resistance to block a 12 volt
charge? Could someone explain this to me?

Chris

J

#### John Popelish

Jan 1, 1970
0
SkeetX said:
I am just starting in electronics, and in a book I was reading it said
that a car spark plug could definatly give me a lethal dose of
electricity, even at 12 volts. I'm still having a little trouble
understanding it, but even if there are 50Amps of current behind that
plug, doesn't my body have enough resistance to block a 12 volt
charge? Could someone explain this to me?

Chris

It is very difficult to to receive a dangerous shock directoy from a
12 volt source, for the body resistance reason you mention. But an
ignition circuit pumps that 12 volts up to a thousand or so volts, and
that voltage has no problem driving a dangerous current through your
bodies resistance. Even on the primary side of the ignition coil,
there are pulses of several hundred volts that hurt like blazes. A
few milliamps across your chest (hand to hand) have a risk of sending

N

#### Norm

Jan 1, 1970
0
The spark plug= Sparks High Voltage not 12V therefore it will hurt. 12V DC
or AC can be used as source (in a circuit) and generate a higher voltage
that can also hurt.

I

#### Ian Bell

Jan 1, 1970
0
SkeetX said:
I am just starting in electronics, and in a book I was reading it said
that a car spark plug could definatly give me a lethal dose of
electricity, even at 12 volts. I'm still having a little trouble
understanding it, but even if there are 50Amps of current behind that
plug, doesn't my body have enough resistance to block a 12 volt
charge? Could someone explain this to me?

A car spark plug is not 12 volts. Ths ignition caoil steps it up to several
thousand volts and that can certianly kill you.

Ian

Replies
4
Views
1K
Replies
4
Views
2K
Replies
43
Views
5K
Replies
12
Views
1K
Replies
17
Views
2K