STEORN DEMO LIVE & STREAM in Dublin, December 15th, 10 AM

[teslaalset]

@omnibus:
How did you measure the output current (of the data in thread #3088)?

What was the attenuation of the probes you used? Do you know the probe resistance by chance?
Sometimes the probe resistance is no more than 1 MOhm, depending on the attenuation.
I noticed your external load is 652KOhm. In that case probe resistance may be of influence.

You measured the values in a DC coupled DSO input mode I presume?

[Omega_0]

Before posting the data I'd mention that, yes, there's a difference in the wave forms. The resistance of the coil and the ceramic resistor was measured with a Keithley 2000 multimeter. The ceramic resistors are four 47Ohm ceramic resistors connected in parallel.

Thats 11.75 ohms. Where should this appear in excel sheet ?
I also could not find 0.23 ohms in your formulas

The resistor sheet has Po = ((E4/0.1936)^2)*(0.1936)+((B4/1.0762)^2)*(1.0762 + 65.2124)
So I assume 0.1936 was the load. I think the resistance of the secondary coil also should be added here, just like you did on primary side.
Btw, when I put the 0.23 value it shows underunity.

The coil sheet has Po = =((E4/0.1939)^2)*(0.01939)+((B4/1.0762)^2)*(1.0762 + 65.2124)
Notice the extra 0 in 0.01939, is that an error ?
Removing the 0 makes it a lot more overunity. Perhaps you should explain these numbers first before doing the troubleshooting.

[Omnibus]

@Omega_0,

Thats 11.75 ohms. Where should this appear in excel sheet ?
I also could not find 0.23 ohms in your formulas

Four 47Ohm resistors in parallel indeed should give 11.75Ohms. I'm measuring this morning (colder weather) 0.1192Ohms (using Keithley 2000 multimeter). Yesterday it was 0.1936. The 0.23Ohms is the active resistance of one of the coils used as load. I have removed the load coil in this experiment and have replaced it with with the 0.1192 resistor (four 47Ohm resistors in parallel).

The resistor sheet has Po = ((E4/0.1936)^2)*(0.1936)+((B4/1.0762)^2)*(1.0762 + 65.2124)
So I assume 0.1936 was the load. I think the resistance of the secondary coil also should be added here, just like you did on primary side.
Btw, when I put the 0.23 value it shows underunity.

Correct, 0.1936Ohms is the load (no it is 0.1192Ohms). The resistance of the secondary coil is 0.5921Ohms and I've included it in the new Excel spreadsheet as you correctly suggested.

Notice the extra 0 in 0.01939, is that an error ?

This is indeed an error. I've corrected it.

Here is the corrected result for 30000Hz:

[Omnibus]

Here are the Excel data:

[Omnibus]

@teslaalset,

The output current in post #3088 is measured by measuring the voltage across 0.1936Ohms resistor and dividing it by that resistance, the same way I did it in the last experiment I posted (the resistance now is 0.1192Ohms because it's colder today). As I've mentioned before, measuring resistance on the fly would be the desirable thing to do but it's impossible, unfortunately.

The attenuation of the probes is 1X. The probes are Tektronix P2221 200MHz 1X/10X passive probes. At 1X the input resistance is 1MOhm +/-3% at DC. My output load is 0.1192Ohms. The DPO is in DC coupled mode, that's correct.