|
Home > Archive > Electrical Engineering > January 2008 > Vechicle circuit grounding
You are viewing an archived Text-only version of the thread.
To view this thread in it's original format and/or if you want to reply to
this thread please [click here]
| Author |
Vechicle circuit grounding
|
|
|
| In vechicles ac current is generated and they are used for lightining
and other purposes. From the dynamo one wire is taken and given to the
bulbsand the other end of the other end is connected to the body of
the vechicle. My doubt is that won't the resistance of the body of the
vechicle include in the circiut. The body of the vechicle is made up
of steel or some metal other than copper. Hence their resistance is
more.
| |
| Andrew Gabriel 2008-01-05, 9:25 am |
| In article <386218ba-0242-4f62-9486-1b58a02d5dab@d21g2000prf.googlegroups.com>,
rtk <rtarunkumar@gmail.com> writes:
> In vechicles ac current is generated and they are used for lightining
No, DC. (In the case of an alternator, is contains integral rectifier.)
> and other purposes. From the dynamo one wire is taken and given to the
> bulbsand the other end of the other end is connected to the body of
> the vechicle. My doubt is that won't the resistance of the body of the
> vechicle include in the circiut.
Yes.
> The body of the vechicle is made up
> of steel or some metal other than copper. Hence their resistance is
> more.
There's so much more effective cross-sectional area, the resistance
is actually a lot less than the copper wires.
--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]
| |
| Palindrome 2008-01-05, 9:25 am |
| rtk wrote:
> In vechicles ac current is generated and they are used for lightining
> and other purposes. From the dynamo one wire is taken and given to the
> bulbsand the other end of the other end is connected to the body of
> the vechicle. My doubt is that won't the resistance of the body of the
> vechicle include in the circiut. The body of the vechicle is made up
> of steel or some metal other than copper. Hence their resistance is
> more.
Resistance isn't just dependent on the resistivity of the material - it
also depends on how much of it is in the circuit.
A conventional steel car body has *lots* of steel. So, unless it is a
rusted-out wreck, there isn't any significant resistance between two
points on the body. There are lots of parallel paths in the body for
electricity to flow through - far less resistance than a wire, even a
copper wire, would provide.
Places that could provide a high resistance, such as engine mounts,
are bridged with short lengths of wire.
--
Sue
| |
| Fulliautomatix 2008-01-05, 9:25 am |
| rtk wrote:
> In vechicles ac current is generated and they are used for lightining
> and other purposes. From the dynamo one wire is taken and given to the
> bulbsand the other end of the other end is connected to the body of
> the vechicle. My doubt is that won't the resistance of the body of the
> vechicle include in the circiut. The body of the vechicle is made up
> of steel or some metal other than copper. Hence their resistance is
> more.
AC is 'generated' by the alternator
Rectified & regulated internally to ~13.8V DC
This DC is used for vehicle power
Resistance of the body is negligable because there is so much of it
Poor negative connections to the body cause electrical problems - mostly
in older vehicles
If you are running high currents to stereos or lights, the negative
cable must be the same size as the positive cable
A sheet metal screw into a panel is not suitable for a high current
negative - run a cable to the battery or use a good size bolt and clean
off the paint
| |
|
| In article <386218ba-0242-4f62-9486-
1b58a02d5dab@d21g2000prf.googlegroups.com>,
alt.engineering.electrical, rtarunkumar@gmail.com says...
> In vechicles ac current is generated and they are used for lightining
> and other purposes. From the dynamo one wire is taken and given to the
> bulbsand the other end of the other end is connected to the body of
> the vechicle. My doubt is that won't the resistance of the body of the
> vechicle include in the circiut. The body of the vechicle is made up
> of steel or some metal other than copper. Hence their resistance is
> more.
Interesting! Got an AC battery to go with that dynamo too?
--
Keith
|
|
|
|
|