Re: Calculating the drain I - SSTC

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: dhmccauley-at-spacecatlighting-dot-com 



You can still use ohm's law here, although it can get a bit more complex.

Remember, ohms law is V = R*I

For this case, its the same as well:

V = Z*I  (where Z is the impedance of your load)

Now since you don't have DC anymore, it gets a bit more complicated.

Now we have V and I represented as functions:

v(t) = z * i(t)

Or  i(t) = v(t) / z
You already know v(t) and z should be quite easy to figure out based on your
measurements of your primary coil.
You'll need to know the ESR of your primary as well as this term should be
added to your calculation.

I won't get into all the nitty detail here, but this should get you on the
right track.
Once you get the function for i(t), you should be able to easily calculate
the RMS current of i(t) and get a
good ballpark RMS current.

Or easier yet, you can just measure it if you have the proper equipment.

Dan


 > On a more serious note, I measured the inductance of my primary today, and
 > found it to be 18.9 mico henrys. How do I calculate the current that will
be
 > flowing through it when I have 300 VDC on the rails, and I am switching at
 > 221.3 KHz?.
 >
 > I remember reading somewhere that sine wave formulas don't work with
square
 > waves, and that somehow harmonics enter into the formula, but I dont
 > remember how it went :-(
 >
 > I'm almost done with this thing! I just gotta build the driver and low
 > voltage power supply!
 >
 > Sue
 >
 >
 >
 >
 >