Inductance of DC Electromagnet Coil. Help

[wingsofdesire]

I am trying to make a DC electro magnet coil. The Coil is wound up to the core. And works fine. But I'm not being able to find out the inductance of the coil. The Resistance of Coil R20= 490 ohms. Impedence is 523 Ohms. 110v give .21 amps. Please Help.

 

[skeptic2]

Is the 110v alternating or direct current? If alternating current, what is its frequency?

 

[technician]

what about this:
Given we have just R and L (no C).
They from a triangle: Z^2 = R^2 + L^2.
=> L = sqrt(Z^2 - R^2) = 182 Ohm.

hth
Ulli

That is not correct, you need to know the frequency as has been hinted at. X_L = ωL

 

[technician]

You say 110volts so I would guess that f = 60Hz (or maybe 50Hz)
The impedance = 110/0.21 = 523Ω. ω Is 2∏60 = 377
So if you do 523² = 490² + (ωL)²...see what you get for L.

 

[modmix]

That is not correct, you need to know the frequency as has been hinted at. X_L = ωL

sure. that's why i deleted my posting - not fast enough...
L measures in H ,-)