To be deleted

[itsu]

Finaly got some drain duration results.

Using 3x 10F caps in series = 3.3F

Charged till 4.15V, activate the circuit, at 4V start the timer, at 3.4V stop timer.

Circuit with feedback      shows drain time from 4V => 3.4V to be average (10X) 10 minutes 14 seconds = 614s
Circuit with no feedback shows drain time from 4V => 3.4V to be average (10x)   9 minutes                    = 540s

So the remove of the feedback shorts the draining time by 1m14s = 74s = 12%.

The graph shows the both situations:

Regards Itsu

[nul-points]

thanks Itsu, your cap draw-down results seem comparable with mine


here is a way to visualise what is occurring with this circuit in terms of average quantity for the transfer of charge (ie. current flow):

say you have 3 watertight containers (2 larger ones, Cb & Cc, and 1 smaller cup Ct) and a timer

(NO FEEDBACK)
after using Ct to fill Cb with a quantity of 20 cupfuls of water,
start the timer, and then at every new minute use Ct to transfer a quantity of 5 cupfuls of water from Cb to Cc;
(so a quantity of water is transferred in one direction only, each minute, from Cb to Cc)

Q1) after the 4th minute of water transfers, how many cupfuls of water remain in Cb?
A1) 0 cupfuls

Q2) what is the average quantity of water transferred per minute?,
A2) (5 cupfuls * 4 transfers) / 4 minutes = 5 cupfuls per minute


now we repeat the test with a slight difference to the water transfer procedure:

(WITH FEEDBACK)
after refilling Cb with 20 cupfuls of water,
start the timer, and then every minute use Ct to transfer 5 cupfuls of water from Cb to Cc, and also transfer 1 cupful back from Cc to Cb
(so 2 different quantities of water are transferred, one in each direction, each minute, between Cb and Cc)

Q3) after the 4th minute of water transfers , how many cupfuls of water remain in Cb?
A3) 4 cupfuls

Q4) what is the average quantity of water transferred per minute?
A4) ((5-1) cupfuls * 4 transfers) / 4 minutes = 4 cupfuls per minute

note that you still have 4 cupfuls of water left in Cb - it would take another minute's transfer event to empty Cb. (this extra runtime behaviour matches what we're seeing with our capacitor draw-down tests)

so, in the posted circuit, if the voltage waveform across a CSR (or equivalent sensor) at the battery terminal shows 2 pulses of different polarity, then 1 pulse is caused by current, Iin, flowing INTO the circuit from the battery to power the components, and the other is caused by current, Ifb flowing OUT of the circuit back into the battery, recharging it.  the average supply current, Isupply = (Iin - Ifb)

in my circuit, the average supply current, Isupply = (Iin - Ifb) = (6.5mA - 1.2mA) = 5.3 mA. (DMM reading was 5.4mA)


np

[nul-points]

indeed, you make them:
3.75V * 6.97mA = 26.14mW (with feedback)
3.75V * 6.45mA= 24.19mW (no feedback)

but i did not make them, i had the Tektronix TDS3054B scope calculate them to be:
15.28mW (with feedback)
13.65mW (no feedback)

Your formula is for DC signals only, while we are dealing with a complex AC like current waveform.
The scope is able to deal with those complex AC like waveforms using its elaborate math functions.

ah, ok

my 'formula' Vsupply * Isupply is the standard calculation for input power calculated from the average Voltage & Current supplied to the circuit

i understand that you're reporting the values provided by the scope, but i thought that those values would have some similar meaning (ie.  that you could multiply the voltage reading by the current reading and that the result would produce some meaningful value for the input power)

in that case, it's not clear to me what is the relationship between the data provided by the scope, and what is the meaning of any individual reading in terms of standard power calculations - eg. is there any reading on the spreadsheet which represents 'average input current' in the conventional meaning of that phrase?


thanks
np

[itsu]

NP,

as said, the scope uses its elaborate math function to compute the data found on the traces it is processing
(here CH1, yellow, voltage times CH4, green, current).
The red math trace presents this data averaged over many samples.

Besides what the math function is doing with the, in this case, data found on CH1 and CH4, i can display the
data on those channels to my likings, like in rms, mean etc.

Normally i put the data on those channels in rms, but if i would put the data in mean, nothing would change on
the math trace as it is still doing its thing with the data.

In post #56 of this thread:
https://overunity.com/16384/flyback-data/msg527867/#msg527867

you can see in the first screenshot that i have the input power being calculated and present the (DC) voltage
yellow in rms and the complex AC current green in both rms and mean (together with the math red calculation in mean).

If you think that the complex AC current in green presented in mean would be more meaningfull, then i could use
that for next calculations, but i still consider the calculated power via the red math trace more reliable. 

Itsu

[nul-points]

ok, i understand what you're doing




thanks
np