Re: Current Shunt
- From: z <gzuckier@xxxxxxxxxxxxxx>
- Date: Wed, 27 Feb 2008 10:27:03 -0800 (PST)
On Feb 26, 7:35 pm, gearhead <nos...@xxxxxxxxxxxx> wrote:
On Feb 26, 1:52 pm, Tim Wescott <t...@xxxxxxxxxxxxxxxx> wrote:
Chris W wrote:
I was considering putting a current shunt in my car to monitor current
draw from the battery. I found a 200 A current shunt and was wondering
if that would be enough. Obviously during normal operation I'm not
going to be pulling near that. But during start I could draw
significantly more than 200 A. The shunt I am looking at is ....
http://www.allelectronics.com/cgi-bin/item/SNT-200/search/200_AMP_SHU....
I'm guessing since it is rated at 200A, it can handle 200A continuously.
If it can, it doesn't seem like short bursts of high current during
start would cause it to heat up too much to cause any problems. If the
200A shunt isn't going to handle the start current, I guess I could find
a way to have it measure current for everything but the starter motor.
Then I could get away with a 100 A shunt.
Normal automotive practice is to run a big heavy cable straight to the
starter (or to a relay on an inner fender), with a smaller wire going
off of that to all of the rest of the electronics. If an ammeter is
installed at all the shunt is in that 'little' wire.
Do you have an overriding need to monitor the starter current?
--
Tim Wescott
Right, just measure the current after the starter.
That's how they did it when they were making cars with ammeters in
them, like my old IH Scout.- Hide quoted text -
- Show quoted text -
yeah, i never saw anybody try to measure starter current, other than
maybe diagnostic purposes. it would be so out of scale with normal
current draw as to either pin the needle, or make the normal readings
infinitesimal; plus, you don't want to put a resistor in series with
the starter, even a small one, thereby reducing the current.
.
- References:
- Current Shunt
- From: Chris W
- Re: Current Shunt
- From: Tim Wescott
- Re: Current Shunt
- From: gearhead
- Current Shunt
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