Resistance values for resolver

I have to check if a resolver is connectable to my controller.
I have diagram included that shows which ratio of resistance (ohm) to inductance (milliHenri) is allowed.
From the manufacturer of the resolver I only get a a value for the stator of (ohms) :
102+j150.
Is 102 here the pure ohmic part and the 150 the inductance, or how do I interpreet this?

Hi!

Close! What you have there is the impedance of the resolver. 102 is the resistance (Good job!), and the j105 is its reactance. It's also measured in ohms. Reactance takes both induction and capacitance into account.

The reactance formula of an inductor is: Xl = 2*pi*f*L (f=frequency, L=inductance in Henries.)

To get the inducatance, we'll need to plug in a value for frequency. Any value here will do, so let's use 1000Hz. Nice, easy math!

105=2*pi*1000*L
L=0.0167= 16.7mH

Now you can go the other way. If you have a known inductance (from your drive spec), you can plug it in for L and find Xl.
NOTE: use the same frequency to get a valid comparison.

Originally posted by JordanCCLark:

To get the inducatance, we'll need to plug in a value for frequency. Any value here will do, so let's use 1000Hz. Nice, easy math!

Click to expand...

My guess is the resolver specs provide a recommended carrier frequency and that the inductive reactance is for that frequency. 3kHz seems to be a pretty popular carrier. But I would need to see the spec sheet to be sure.

Keith

kamenges said:

My guess is the resolver specs provide a recommended carrier frequency and that the inductive reactance is for that frequency. 3kHz seems to be a pretty popular carrier. But I would need to see the spec sheet to be sure.

Keith

Click to expand...

These are minimal resistance - inductance values

Okay, now we have something, with f=5000. Plugging in our values:

105=2*pi*5000*L
L=3.3mH

Looks like you should be good.

As a side note, fxsolver.com has many formulas for many different areas. This should get you started for reactance:
http://www.fxsolver.com/solve/share/k0Knis68sn9GFsEMoGgU2w==/