I assume you referring to table in meg2.pdf

Attaching original .xls file (and .pdf version in case you can't open .xls files)

In this calculations I used divide by 12 coefficient for output power calculations (not 10) as theory suggests.

-V.

Hi Vasik,

Thanks for clarifying your procedure to calculate the power levels. Using your protocol, I've attached scope shots below of the same transformer design and circuit I've been testing that will allow us to determine the variables to use in your equations. For the record, the load resistance in this case is 16.94 ohms non-inductive.

The pulse repetition time Ts = 50ms = 50000us and the power supply Ups = 30v dc.

The remaining parameters are pulse duration Tp = 11.12us, peak input current Imax = 0.106A, peak output voltage Uout = 1.74v, and the output transient time Tout = 1.068ms = 1068us. Therefore, the input duty factor Q = Tp/Ts = 0.0002224 and the output duty factor Qo = Tout/Ts = 0.02136.

The input power in mw is Ps = Ups * Imax/2 * Q * 1000 = 30 * .106/2 * 0.0002224 * 1000 = .354mw.

The output power in mw is Pout = Uout * Uout * Qo * 1000/12 = 1.74 * 1.74 * 0.02136 * 1000/12 = 5.39mw.

So, using your method the COP = Pout/Ps = 5.39/.354 = 15.22 .

For comparison, my method to determine the COP using energy levels is as follows-

Measure the mean input energy using the scope pix "Vt Tp". The Math channel(red) indicates a mean power of 1.494 watts over the period of 11.12us resulting in an input energy level of 16.61uJ.

The output is measured by taking the rms value of the output voltage across the 16.94 ohm load during the collapse time period. Referencing scope pix "Vt Tout" we see the output voltage on Ch3(pnk) is 0.4582v rms and the period is 1.068ms, so the output energy level is .4582^2 / 16.94 * 1.068e-3 = 13.24uJ.

Using my method the COP = 13.24/16.61 = .80 . These energy levels could be converted to power levels over the pulse repetition time Ts with the same resulting COP as you well know.

So, it appears that our numbers differ due to our different measurement protocols if I have done the calculations above correctly! The question I guess is which method is correct?

Regards,

Pm