Thursday, August 30, 2018

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)


Tuesday, August 28, 2018

Predicate research for using the LED as a photodiode

in prior of doing the following i measured the target Blue LED that did output some millivolts but no nanoamps , then a high efficiency Blue LED that i used for below experiments (← the series array of theses gave pretty much alike data than the single one) . . . then the iR LED parallel array from the (used for . . . ?? pre-clearing the image in) laser printer , it output over 1V and i guess several microamps . . .

. . . all that illuminated from the narrow beam 1W Power LED

the conflicting data (with web) is that when illuminating the LED it outputs fw.-polarity voltage -- e.g. [+] from anode and [-] from cathode * . . . all 3-types of the above without the exception ???

Note* ::  no conflict ( , conflict ( . . . there was a site that actually textually claimed that ? intentionally or not . . . can't re-find it at this time . . . and it was not the only one such . . .)

first couple of web found setups (slightly modified)

and my own guesses of j-Fet setups


Wednesday, August 22, 2018

LM311 Testing for 5V setups

Tests ::

↑↑ !!! Don't follow/assemble these !!! ↑↑

The output speed does NOT much depend on pull up resistor values (below equal 1 kΩ @ 5V)





Sunday, August 19, 2018

Re Electret Amplifier

the lm324 turned out to be too unstable thing for this operation ???

replaced it with LM308

the ↓↓ Ti-s Bullshit Spice Model ↓↓ generated problems at frequency pass - so i had to dump it out


Saturday, August 18, 2018

This is where the Spice spectrum analysis fails high time . . .

i guess the auto bias at Stage 1 -OR- that specific LM324's Spice model - is what does not get recognized here correctly (Shit happens)

Update 2019.06.03 :: LM324's Spice model has an input zero mismatch of +17µV -- this however does not represent an AC analysis error !!! in static DC bias --AND-- in DC amplifier configuration . . .

. . . there was an OpAmp Spice model that failed AC configuration ((a capacitive coupling)) analysis ... and it may be the same LM324 ...

... also the frequency plot can be achieved by multi-passing a transient analysis with stepped frequencies and integrating the DC offsets and by these integrating the AC amplitudes for the voltage points in interest (gonna be time consuming but doable) . . . if you want to waste a day or two for it you can further track the slopes in transient analysis and estimate by these a rough phase shifts (further by inserting a marker signal -- such as -- spike or missng or inverted period/cycle the greater than 2πN offsets can be determined) -- the fast part example ::

in practise ::

. . . and still not coz higher frequencies take time to integrate

it might be considered (by tiling 0-ohm impedance AC sources in series) -- to reach measure point by a lower fixed frequency and then swapping to SAMPLED ONE --!!!-- such causes a "frequency jump" that causes a bias disbalance and even when done in phase at zero-crossing it BANGS the offsets off their values - may take long to settle again . . . thus

it could occur that if we make our own frequency source that is stepped to higger smootly by ??
(-π to π) + 1 "sine" at desired time the BANG won't occur (never tested) . . . ← well in last case it's still possible to automate the entire process . . .

( . . . only it must be in prior be determined the smooth transition times for  frequencies for the speciffic circuit , etc. . . . )


Tuesday, August 14, 2018


i overshot with my custom LM324 models . . .


degraded the model ::

required while more accurate I/O and supply currents do matter

Monday, August 13, 2018

modified another circuit

src. :: (seek text tlc -- for TLC27L2)

mod. :: didn't like quite a lot of things about it's operation so . . . it auto optimized itself to ↓ that ↓

the Spice shows a stable error free graph -- which i quite doubt would be that in real . . . but it's an add up concept to the few long interval timers out there . . .


Friday, August 10, 2018

weak input signal case study LM301 versus LF347

attempted to use the smd j-fets for the high ohmic OpAmp input but they start failing (at that) at about 80kΩ input -- top-down : each previous has some drawbacks !

about : ,

quick 5V mod.


Thursday, August 9, 2018

some audio experiments

!!! incorrect !!! stereo depth adjustment circuit
it would work better with VGA(variable gain amplifier) or analog voltage(/signal) multiplier
this one however explains the concept . . . and has a bug (i simplified things here ... a bit too much) -- the sum(avg.) must be reduced when differential is increased and vice versa (the varying resistors should be at the signal inputs - not at the reference inputs at the 3-rd step - and must follow the function that sets their parallel value to the same that the one that goes to the ground = 8 potentiometers connected by the same axle ??? or additional stage to VGA the inputs to correct values . . . whatever)

teh raight ver.

a pseudo stereo circuit


Tuesday, August 7, 2018

µA776/LM4250/LM301 models comparison

differential Sine ::

Note : the max.input voltage range is limited to the half of the half of total supply by common mode variation (e.g. in single sine input the value may be higher !!!)

 µA776 against LM4250 differential Pulse ::

 К(Р)1407УД2 against LM4250 differential Pulse ::

 К(Р)157УД2 against LM301 differential Pulse ::

NB! -- why there is no Spice models to download here is because i'm not the Spice model factory -- i would rather download these from internet - if there were any - 8 billion people - a lot of Spice users . . . no any g.d. models !!!

mine are not that good that you'd know where or whether to use them and how much or when to trust them -- i don't want to populate chaos ... (there likely is an email somewhere and a comment area if you think you need any)


some 555 spice models' tests

inter-model timing differences

input sink/source currents