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Course work help

Hi

I was wondering if some one could help me with my assignment.

Normally I wouldn't ask but I'm struggling to find a formula

I'm stuck on the 1st question, I have found two formulas I= Tω/V and Ea = 2πNT/Ia re aranged Ia = 2πNT/Ea

Both give different answers and don't take into account the back EMF.

Can any one give me some pointers please. I have looked through all my books but can't find any answers.

Any help would be appreciated.

Thank You

Daniel Robinson

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0 Former Community Member over 4 years ago

Daniel,

Well spotted. I could claim it was deliberate but, unfortunately, I need some new specs. 5000RPM is just about feasible with good bearings: Tesla super car?

Your part I calculation is not quite right - 2piNT is the correct mech power but the relevant voltage (Ea) is 115V: the other 5V is dropped across the resistance, resulting in heat loss.

That is why I recommended to calculate mech power first. That part of the elec power which converts to mechanical is Ea times current.

Thus IxEa=2piNT

Chris
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0 Former Community Member over 4 years ago

Daniel,

Well spotted. I could claim it was deliberate but, unfortunately, I need some new specs. 5000RPM is just about feasible with good bearings: Tesla super car?

Your part I calculation is not quite right - 2piNT is the correct mech power but the relevant voltage (Ea) is 115V: the other 5V is dropped across the resistance, resulting in heat loss.

That is why I recommended to calculate mech power first. That part of the elec power which converts to mechanical is Ea times current.

Thus IxEa=2piNT

Chris
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Vote Up 0 Vote Down

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