Meanwhile, i was revisiting the video at the first post of this thread and noted the following:
Joel says at:
1:03
"i charge Cap A (our cap C1)
to 1.96V and discharged the other cap (pointing to our cap C2).
1:29
"switching in Hz which is the optimum" pointing to the FG which clearly shows to be set to 26.2 kHz. (so is it really the optimum then?)
1:55
"After 1 hour (after start i guess)
we have 0.1V drop on Cap A (our cap C1)
and a same 0.1V (-10%) increase on the other cap (our cap C2).
2:28 pointing to our cap C3
"this is a set of 10000F" which is hard to believe as the 4 caps are in series meaning 40000F each.
2:36 pointing to our cap C3
"set to zero" meaning at the start it was discharged to 0V IMO.
7:13
"it ran all night" showing the voltage across cap A (our cap C1) being 1.78V which means coming from 1.96V at start, a drop of 180mV
7:55 we can see written on the top of one of the 4 series caps "10000", see attached picture. So not 10000F, so still very doubtful these are real 10000F caps (4 in series mean 2500F).
In the comments below this video, there are also doubts about the value of the used C3 caps, but questions asked Joel are ignored (which i often see in his other video's where these 4 series caps are used.
He uses these 4 series caps already in this video:
https://youtu.be/Xr9QSD889ZA from 2 years ago, in which also the now used transformer is shown (Prim. 120VAC 60Hz 15W - Sec. 2.3V 3A).
From the above, we learn the values on his caps to be:
C1 charged to 1.96V (500F = 960.4J).
C2 and C3 drained to 0V
He says cap A (C1) dropped 100mV in the first hour and C2 (his other 500F cap) gained 100mV (meaning it was charged to 0.1V) and that this was going on in this relation.
He also says that at the time of the video the device was running all night and showed that C1 (his cap A) now measured 1.78V, so a drop from 1.96 of 180mV.
This thus mean, seeing the above statement, that C2 now should have gained 180mV so it should now measure 0.180V.
C1 started with 1.96V = 960.4J and ended with 1.78V = 792.1J so lost 168.3J
C2 started with 0V and ended with 0.180V = 8.1J (which is hard to believe IMO, but as it was never measured or mentioned it could be anything).
C3 started with 0V and ended with 2.51V which for a 2500F cap mean 7875J (which is also hard to believe).
If we follow the suggestion of one of the responders under Joel his video that the 4 series caps more look like 100F caps (meaning a total of 25F) and we take the shown 2.51V then we have an energy of 78.75J in these caps which is much more believable and matches more the results i have.
I guess we will never know, as Joel ignorers questions about his 4 series caps value up till now.
Itsu