shramana
Aug24-08, 12:03 PM
1. The problem statement, all variables and given/known data
A dc machine(6W, 120V,1500rpm) is separately excited and delivers rated current at rated terminal voltage.Field winding is connected to 120V supply. Rfw=100\Omega.
a) Determine the value of field current
b) Determine the value of Rfc required.
2. Relevant equations
Vf= IfRf
3. The attempt at a solution
In the question the value of Vf is given, while both If and Rf are variables. So I need another relation to find out both the values. Is there another relation that I'm missing?
A dc machine(6W, 120V,1500rpm) is separately excited and delivers rated current at rated terminal voltage.Field winding is connected to 120V supply. Rfw=100\Omega.
a) Determine the value of field current
b) Determine the value of Rfc required.
2. Relevant equations
Vf= IfRf
3. The attempt at a solution
In the question the value of Vf is given, while both If and Rf are variables. So I need another relation to find out both the values. Is there another relation that I'm missing?