YX8018 ~about "guessing the operation"

→NB←! the following has pretty much nothing to do with the actual chip !!! ←
i just matched some known or guessed data into random simulation substitute

from what we can conclude ::

1. the device operates best at certain fixed supply voltage (there might be one built in to YX8018)
2. the best efficiency is occurring below the certain output power = you should not replace the inductor to lesser inductance one without making sure :
   a) that there's enough power to drive the inductor (somewhat aided by the 1µF and 5µH caps inductors at the schematic) ,
   b) that the inductor won't be driven into saturation
   ( ↑↑ ← both are primarily indicated by a notable drop in efficiency compared to initial -- however the lesser inductance does, by the idea, give a* higher output power and usually there is some efficiency drop for "trade" to such* )
3. the onboard inductor in my particular solar lantern has 4Ω series resistance (it might be useful to protect the mosfet from peak power ? from accidental out of cycle re-trigger . . . or provide some voltage regulation for more up to charge battery) , otherwise there's a plenty of room to install a better inductor (such might also cause the over-voltage at the switch drain -- it must be tested out at max input power)

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[Eop]

about 6F22

i was wasting some half a day to find out the max. safe discharge current rate for carbon zinc type
there was no such data avail.
-- so i had to make a best guess about

a fuzzy logic follows ::

it is statistical nonsense but since i had no other data avail than GP-s datasheet then what it seems / was assumed is that the average drain over longer time is somewhat constant . . .

. . . so if you want to design an application that uses 9V C-Zn battery then something optimal value is 12mA or below -- that is -- if it is to work 24/7

( it is amazing that we don't have that value available -- if you overload the battery it gonna heat up that first boosts the chemical reaction but likely roughly over 40°C (104°F) it starts to damage internal chemistry further on there might be acid or alkaline leak or explosion or even fire when Li-ion gets in contact with oxygen -- so all such totally insignificant stuff no one needs to know exactly -- especially the EE app. designers )

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[Eop]

3V constant current LED Flasher concept designs

the 2N2222 2N2907 1N4148 1N5817 based White LED (with 3+ V voltage drop) flashers - occasionally utilizing the Red LED-s as zeners

constant current mode up to 2.5Ω - a SUM of the internal resistances for 2x 1.5V batteries

constant current mode up to 2.2Ω
note! : that these are concept design simulations that are not been optimized nor built/tested in real

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[Eop]

BWD engineering the GPSA006W3

very apx.* op. of the Solar Charger

PS! the numeric values on the plot are illustrative*

the valid formula for thishit seems to be ::
IF no clouds
prod. ( ( 8h/d + 4/2 h/d = ) 10h/d ) × 43.6mA = 436mAh/d
apx. 5d to charge batteries from 20% to 100% of nom. capacity
( usually it takes 2 to 3d . . . ? 55% to 95%  e.g 4x SB in parallel (60 in²) should 2 the 3-ck in 1d )

Update : results of a "Quick Test" (applies to solar cell only) ::

EP -- ( values below (have likely 1.5 to 2.5 significant digits !!!) ) based on solar-cell´s double output power !!! or max. power diffused on internal resistance at short circuit !!! -- sampled on 2 spring afternoons @ apx.60°N (Sun filtered by Space´s dust + Earth´s atm..+ packet-window´s 2-ble layer of Si-glass)

Est.Peak double output power ( P_2PK (= ε · r) ) : 1.163698202 W
*Speculative "no load" terminal voltage ( ε ) : 6 V
*Computed internal resistance ( r ) : 30.935856 Ω

note : * --  the values are valid for P_2PK or at max. "intensity of a Sun" and will respectively drop,increase at lower intensity levels + there are reason to believe that ε , r also depend on load ( I²R )

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Update+ : refined experiment (sampling the I , U and ε) ::

[Eop]

father (Darth Sidious ;p) asked a "Stupid Question"

as why the automotive cellphone charger finishes much quicker than the wall supply
heres what i came up with (though i'm not so shure about it)

Simplified Battery Charging

related formulas ::
(*) -- ! not proven !

E(J) = Q(A·h)·ε(V) ΔE = dt·P(W) ΔQ = I·t dQ(A·s) = dt(s)·I(A)	ε = a·rb = E/Q Δε = a·Δ(rb) = Δ(E/Q)	P = U²/r = I²·r α²Q - αE = 0 (Q/QMAX)² - (E/EMAX) = 0 (Q/QMAX)² = E/EMAX (*) Q² = Q²MAX/EMAX(=ϰ) ·E E/Q = Q/ϰ	ε = a·rb r = (ε/a)1/b
(E=)Q²/ϰ - Q·ε(=E) = 0 Q/ϰ - ε = 0	E = √(ϰ·E)'·ε √(E/ϰ)' - ε = 0 E = Q·ε ε = E/Q =  Q/ϰ	ε = u + U = i·r + U εTF = i·rTF + U ε℩B = i·r℩B + U	εTF - i·rTF = ε℩B - i·r℩B εTF - ε℩B = i·( i·rTF - i·r℩B) i = ΔεX/ΔrX

[EoP]