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  #11  
Old 02-22-2016, 05:19 AM
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Is there a voltage drop across the shunt? I hope NOT! there should not be more than .1 V drop per connection, .2 for battery terminals in any circuit.....
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  #12  
Old 02-22-2016, 07:32 AM
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Quote:
Originally Posted by bret View Post
Is there a voltage drop across the shunt? I hope NOT! there should not be more than .1 V drop per connection, .2 for battery terminals in any circuit.....
Yes there is - that's the point of the shunt, it's how they measure the amperage flowing across it - but it's a small voltage drop, at one millivolt per amp. If you are flowing 30 amps through the shunt, the voltage drop across it is .03 volts. For our purposes it really wouldn't matter which side of the shunt you used for a system voltage tap, but on mine I used the battery side of the shunt.
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  #13  
Old 02-22-2016, 07:50 AM
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Originally Posted by airguy View Post
Yes there is - that's the point of the shunt, it's how they measure the amperage flowing across it - but it's a small voltage drop, at one millivolt per amp. If you are flowing 30 amps through the shunt, the voltage drop across it is .03 volts. For our purposes it really wouldn't matter which side of the shunt you used for a system voltage tap, but on mine I used the battery side of the shunt.
That is good info, I did not even think about that.......now I need to go back and look at my wiring......
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  #14  
Old 02-22-2016, 07:54 AM
Flyingleap Flyingleap is offline
 
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Greg Does your shunt happen to measure the starter current too? Always wanted to know the inrush at initial rotation. Have heard anywhere from 400Amps to 150Amps.. John
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  #15  
Old 02-22-2016, 08:01 AM
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Dynon says not to put it inline with the starter, but there are three other locations for the install.
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  #16  
Old 02-22-2016, 08:08 AM
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No, I don't measure the starter current. I have my shunt set to measure the total current in/out of the battery (other than the starter) to measure a true charge/discharge scenario, after alternator corrections. So if I'm consuming 23 amps of power but the alternator is handling all of it, I'll show 0 amps on the shunt.
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  #17  
Old 02-22-2016, 08:12 AM
Flyingleap Flyingleap is offline
 
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Yep, a Dynon might not like the kickback voltage along with if there
was a loose connection on the shunt with full 14 volts applied to input.
John
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  #18  
Old 02-22-2016, 05:08 PM
DragonflyAero DragonflyAero is offline
 
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I do have the shunt to measure amps also. For volts I connected to a miscellaneous buss from the VP-X. Seems the main interest in voltage is to know if the voltage regulator has run amuck so you can shut down the alternator before everything gets fried.
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