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Old 11-06-2018, 08:37   #16
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Re: Installing Battery Monitor - cable gauge

Reading this with interest. Sorry for such a beginner question but - what is the shunt and what does it do? Trying to learn.
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Old 11-06-2018, 08:51   #17
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Re: Installing Battery Monitor - cable gauge

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Reading this with interest. Sorry for such a beginner question but - what is the shunt and what does it do? Trying to learn.

Ammeters & Shunts 101: Ammeters & Shunts 101
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Old 11-06-2018, 09:33   #18
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Re: Installing Battery Monitor - cable gauge

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Ammeters & Shunts 101: Ammeters & Shunts 101
Perfectly explained - thanks!
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Old 11-06-2018, 09:44   #19
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Re: Installing Battery Monitor - cable gauge

The thing that constantly amazes me is how accurately a huge shunt like say 500 amp can measure small currents down to the 1/10 amp it seems
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Old 11-06-2018, 09:52   #20
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Re: Installing Battery Monitor - cable gauge

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The thing that constantly amazes me is how accurately a huge shunt like say 500 amp can measure small currents down to the 1/10 amp it seems
It's measuring voltage drop not amperage. It's probably as good as the meter.
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Old 11-06-2018, 10:02   #21
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Installing Battery Monitor - cable gauge

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It's measuring voltage drop not amperage. It's probably as good as the meter.


I understand how it works, it still amazes me at how accurate electronics can be.
The helicopter I used to fly had a system that tracked my Head position with a very high degree of accuracy, it knew your head position within less than a millimeter. It did that by timing how long an IR pulse took to be received by the receivers on the helmet.
So how long does it take light to travel 1mm, knowing that it痴 traveling 186,000 miles per sec? I知 amazed that that time interval can be measured, whatever it is, just as I知 amazed that the voltage drop that corresponds to .1 amp on a 500 amp shunt can be measured.
However I guess I知 easily impressed.

I知 an analog guy, mechanic, digital electronics are PFM to me.
You know, pure magic.
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Old 11-06-2018, 10:16   #22
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Re: Installing Battery Monitor - cable gauge

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I understand how it works, it still amazes me at how accurate electronics can be.
The helicopter I used to fly had a system that tracked my Head position with a very high degree of accuracy, it knew your head position within less than a millimeter. It did that by timing how long an IR pulse took to be received by the receivers on the helmet.
So how long does it take light to travel 1mm, knowing that it痴 traveling 186,000 miles per sec? I知 amazed that that time interval can be measured, whatever it is, just as I知 amazed that the voltage drop that corresponds to .1 amp on a 500 amp shunt can be measured.
However I guess I知 easily impressed.

I知 an analog guy, mechanic, digital electronics are PFM to me.
You know, pure magic.
I got a kick out of the end statement. Your not alone. I never liked meters that flash that last digit up and down at you.
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Old 13-06-2018, 22:35   #23
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Re: Installing Battery Monitor - cable gauge

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Originally Posted by a64pilot View Post
I understand how it works, it still amazes me at how accurate electronics can be.
The helicopter I used to fly had a system that tracked my Head position with a very high degree of accuracy, it knew your head position within less than a millimeter. It did that by timing how long an IR pulse took to be received by the receivers on the helmet.
So how long does it take light to travel 1mm, knowing that it痴 traveling 186,000 miles per sec? I知 amazed that that time interval can be measured, whatever it is, just as I知 amazed that the voltage drop that corresponds to .1 amp on a 500 amp shunt can be measured.
However I guess I知 easily impressed.

I知 an analog guy, mechanic, digital electronics are PFM to me.
You know, pure magic.
what's more amazing is the shunt is the engine room and gauge is 50' away with ~20awg wire and measureing mili volts 50' downstream. not just inches away from the shunt which would be hard enough.
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Old 23-06-2018, 09:07   #24
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Re: Installing Battery Monitor - cable gauge

I have to remind myself how little current is carried by those shunt to meterface connections. Even if the shunt is near its maximum amperes.
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Old 23-06-2018, 10:48   #25
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Re: Installing Battery Monitor - cable gauge

It all depends on what you are used to. I am very familiar with AWG and very comfortable using that system.

On the other hand I have some British friends who are perfectly happy giving their body weight in stone. That unit of measurement is still a bit of a puzzle to me.

Cheers!

Steve
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Old 23-06-2018, 11:47   #26
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Re: Installing Battery Monitor - cable gauge

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what's more amazing is the shunt is the engine room and gauge is 50' away with ~20awg wire and measureing mili volts 50' downstream. not just inches away from the shunt which would be hard enough.
The impedance of the shunt is nil and the meter is high so your right. The wire will carry that small current which we read as a ratio of impedance.
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Old 23-06-2018, 12:22   #27
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Re: Installing Battery Monitor - cable gauge

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It all depends on what you are used to. I am very familiar with AWG and very comfortable using that system.

On the other hand I have some British friends who are perfectly happy giving their body weight in stone. That unit of measurement is still a bit of a puzzle to me.

Cheers!

Steve
One stone about 6 kg or 14 lbs. I've read that the length of feet and inches would change as new kings assumed the throne. Even to this day (weight mass) is defined by physical standards (a gold or platinum one kilogram bar someplace in Paris).
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Old 23-06-2018, 14:09   #28
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Re: Installing Battery Monitor - cable gauge

Fun fact

Reason the early US stuck with imperial units, Secretary of State Thomas Jefferson requested France send over a 1kg standard weight, but the ship got waylaid by pirates.
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