To be deleted

[itsu]

Thanks void,

Yes, this "multiply each corresponding point for the current and voltage waveforms
              to get the instantaneous power for each point set, and then takes the mean of
              all those multiplied values",
is for me the most (only) accurate way to determine average power on such waveforms.

I do not even want to think about having to do the multiplication of the waveform points etc, by hand 

Itsu 

[Void]

Hi Itsu. In my case it was not done manually. I exported all the points for a period of time
for the voltage and current waveforms into a CSV file, and then used the formula features of Excel
to do the calculations automatically. Works quite well.

Yes, for any asymmetrical waveform which goes both positive and negative, even using the RMS feature
of a scope is likely going to be inaccurate, as I think many if not most scopes only look at one half of
the waveform (postive or negative half) to do the RMS calculation. The method you are using which makes
use of a current probe and voltage probe and then uses a math function to calculate the average power consumption
is the only reliable way to make power measurements on those types of waveforms, assuming the probes are
reading reasonably accurately.

In the 'efficiency' calculation I did above, the discrepancy between the input power and the total 'output power'
may possibly be due to the current feeding back from the feedback LED into the battery not properly
being taken into account. If you measure the battery voltage with a scope probe and the battery
current with a scope current probe and use your scope math function to compute the average input power,
then that should properly take into account the feedback current from feedback LED, if that is not what you
did previously. Then the input power and total 'output power' should come out more closely, I would think,
as the power dissipation in the coils and ferrite core is probably not very significant.

I have done a lot of testing with these type of circuits and have never seen any signs of OU
in regards to them, and nor would I expect any OU there since there is really nothing
out of the ordinary included in those types of circuits, unless maybe someone does something very
unusual with a ferrite or iron core.

[nul-points]

I received my BC327-25 transistor, so build a new setup using a PCB instead of the breadboard.
The breadboard is kind of unstable and i want repeatable results.

The setup is shown below.

Using:

the new BC327 transistor,
the same transformer,
the same 50K pot,
a green feedback led,
a white (10mm) load led,
a ceramic 47pF cap,
a 100uF electrolytic capacitor and
the 3.7V 3.1KWh (840mAh) battery pack

It has an on/off switch and elevated leads so to be able to put the current probe almost anywhere.
The transistor and potmeter are removeable.

Will do again the measurements this weekend.

Regards Itsu

nice build (as always!) Itsu, the parts list is looking good

i'm glad to see that you have confirmed a bidirectional supply current, consisting of both negative and positive pulses (one relating to the feedback path and the other to the main drive path)

i'll be meeting with family for a couple of days now, but should be back online later on Sunday

i hope your internet access has been restored - we've had outages on the cellphone network over the last couple days (that was fun!)

regards
np

[Turbo]

yes yes is that a ferite core ?
your almost there.
there is a specific mark and a space ratio.
fire the pulse train and vary the frequency until you get a response back in the space (null) time that the transistor is off, then when you got the sweet spot frequency right, fine tune the pulse train duration and adjust the space time lastly.

[AlienGrey]

The thread label is FLY back In order to achieve a true fly back you need a charge time on a tv its like 52usec and a return time (energy dump)
into the flyback of 12 microseconds but I presume you want to beat the magnetic vortex known as lens law in that case you might want to go
a lot faster than 64 usec and shouldn't the horn waveform be the other way round without the ringing oscillations try putting the scop on the
transistor base to see if that's got a clean cut off signal.