Ron H said:
Of course, an inductance meter would solve your problem.
This is the first time I know that there is a thing called an "INDUCTANCE" meter !! :roll: So, is it cheap? Or it would cost me a fortune? Truly, I've never heard about it before! Maybe I could hack a DMM and turn it into an inductance meter?? Any ideas about that would be so helpful.
Ron H said:
BTW, I don't think you can do it if you have a load on the secondary. I'm assuming you don't.
Could you clarify that please? At the moment, no I don't have a secondary load. However, I'll add one later. What I am building here is a power supply, and I am trying to figure out the maximum current that the primary winding could handle. That's why I am calculating the current and inductance.
Nigel Goodwin said:
You've also never mentioned what load is on the transformer, which is obviously vital - even if it's got no load!.
I am afraid I didn't get that quite well Nigel! How it well affect the primary even if
it's got no load? Later (but not at the moment), my load will be a rectifier bridge, some filtering capactiors and a voltage regulator (LM150 with 1.2 < Vout < 35 and max Iout 4.5A).
Well, I might have a good way to measure the inductance. If I place a
high-power resistance Rt (to limit the current) in series with the resistance and inductance of the winding, then measure the current, I would be able to easily solve for L using the eqn. :
|I| = |V| / |Z| ---->>> |I| = |V| / [ [Rwinding + Rt] + j w Lwinding]
Now, everything is known (|I|, |V|, Rwinding and Rt) except the imaginary part of the impedance, that is, the inductance that I want to find. After that, I'll remove Rt. Then, the only impedance that will exist is that of the transformer's winding. Rwinding is measured using an ohmmeter. Lwinding
have just been calculated. So ...
Imax = V(mains) / [ Rwinding + j w Lwinding]
Any comments or suggestions about this way?? Oh another thing .. How could the secondary load affect the previous eqn ? Also if there was no load .. how the eqn is affected ?
Nigel Goodwin said:
Or is this just a class or homework question?.
No, it's not a homework question. I am just a hobbyist, I am not an electronics engineer or something :lol:.
thnx.