Stop in for a cup of coffee
All non-inductive ammeters have shunts in parallel with the indicating circuit. The needle deflection is calibrated to the shunt's resistance, which is very low. A typical multimeter won't show it accurately if all.
The ones in most of our cars have an internal shunt -which is just a big flat plate. Around '73 full size Chryslers started getting externally shunted ammeters, and in '76 even A-bodies have externally shunted ammeters.
If you check aircraft and marine supply stores, they often sell externally shunted ammeters.
Part II
An externally shunted ammeter would be a good way to go.
Two choices:
a. Measure all of the current produced by the alternator. Easy, place the shunt in the alternator output wire.
b. Measure all of the current used by the system. Not possible with the original strategy. Need to wire it up differently.
But seriously - Funny both and BillGrissom say brought up circuits 101 today. I'll tell you what. What I got at NJIT was very minimal. Knowing it would be important, I signed up for Electro-mechanical systems as a senior elective. On the first day of class we discover it was changed to "micro-mechnical" systems. Total BS. Not much I could do about it. Only thing I got out of it was a level of proficiency in laplace transforms.:BangHead:
Volts when there is no electricity flowing and when there is a circuit working may not be the same!
When its flowing, if there is resistance, where we measure the pressure can make a difference.
There may be 80 psi at the 3rd floor balthroom when the valve is shut, but if its a calcified 1/2" supply line, and you're running the shower, its going to be something less than 80 psi at the valve. And if someone is using the second floor bath..
Part I
All non-inductive ammeters have shunts in parallel with the indicating circuit. The needle deflection is calibrated to the shunt's resistance, which is very low. A typical multimeter won't show it accurately if all.
The ones in most of our cars have an internal shunt -which is just a big flat plate. Around '73 full size Chryslers started getting externally shunted ammeters, and in '76 even A-bodies have externally shunted ammeters.
If you check aircraft and marine supply stores, they often sell externally shunted ammeters.
Part II
An externally shunted ammeter would be a good way to go.
Two choices:
a. Measure all of the current produced by the alternator. Easy, place the shunt in the alternator output wire.
b. Measure all of the current used by the system. Not possible with the original strategy. Need to wire it up differently.
Typical engineer edumacation. Where's our translator?
But seriously - Funny both and BillGrissom say brought up circuits 101 today. I'll tell you what. What I got at NJIT was very minimal. Knowing it would be important, I signed up for Electro-mechanical systems as a senior elective. On the first day of class we discover it was changed to "micro-mechnical" systems. Total BS. Not much I could do about it. Only thing I got out of it was a level of proficiency in laplace transforms.:BangHead:
And here's the mistake I made too many times until it sunk into my head.
Volts when there is no electricity flowing and when there is a circuit working may not be the same!
When its flowing, if there is resistance, where we measure the pressure can make a difference.
There may be 80 psi at the 3rd floor balthroom when the valve is shut, but if its a calcified 1/2" supply line, and you're running the shower, its going to be something less than 80 psi at the valve. And if someone is using the second floor bath..