Monday, April 23, 2018

. . . 3x

sequential ½ to 2x per stage positive factor amplifier ::


? fast 1x to 1.77x amplifier -- i just try to get a grasp of these things . . .


another 200kHz cascadable "absolute" multiplier



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Saturday, April 21, 2018

prev. follow up x2

modified known (but much likely a lot) simplified circuit


versus not so much slower but a lot more simple circuit



update :: 2018.04.21 -- about the poor performance of above . . .





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Wednesday, April 18, 2018

prev. follow up

1 quadrant multiplier - divider -- exact but tending to unstable ??




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Monday, April 16, 2018

examining a couple of web variable gain amplifier circuits

attenuating

the 0 to 34 mV  control voltage range sounds like a bit utopistic here
(everithing else looks good however)




amplifying/attenuating



2018.04.18 -- Update ::

bipolar v. of the previous


integrated analog multiplier substitute for VGA



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Wednesday, April 4, 2018

theoretical experiment of 3 to 12 V boost converter

Simple , minimal ::

. . . with error as switch gets near constant 18mA to it's base due xa should be xi


however using cascade drive for switch poses problems -- also a good definition method for vc2 (LMx39/x93 OUTP)


some fixes -- no change . . . need to opt. the drive power usage


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Wednesday, March 28, 2018

after getting enough of the shortcomings with the quadrature and the wien bridge

these ones are not much better . . . yet :

  • + the oscillation amplitude is determined
  • + the oscillation voltage range is defined (offsets)
  • – unfortunately avail. starting from above the 200Hz
  • + the fixed frequency can be set by RC






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a couple of more 5V 32k osc.-s

a tuned (this time) j-Fet amplifier stage




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Wednesday, March 21, 2018

yet another 32768Hz Quartz Osc.

Blind tuned to work with some consequences from . . . at 5V v. of it . . .

-- with the single BJT stages and the battery feed and "sensitive"(tuned) oscillators -- it is most unlikely to get anything "properly" to work -- . . . -- moreover with the 1.2 volt battery the grid has to be tuned to work in 3 different areas of operation of the bipolar transistor -- low-voltage (below normal) , normal voltage (for BE CE voltage drops) and hi-voltage (above normal) -- that has to be achieved with fixed biasing elements -- . . . -- in below circuit the critical elements appeared to be C1 , C8 , C4 , C10 -- less C1 more C8 ... also the series connection of C4 and C10 = Cp of the X-tal resonator it first started to "charge" the X-tal with ratio 1.2x : 6x Cp but as i increased C8 the opt. ratio changed to 1.5x : 3x Cp ???


the "above normal" range ↓↓ -- i just fast tuned it just to "charge" the X-tal -- this to see if the current waveform for X-tal goes "trapezoidal" (← failure in a sense of frequency stability -- i assume) or stays Sine . . . . . . . . . well it stayed sine -- but for this one the further frequency tuning and likely some attenuation is a must ↓↓↓↓ (see next) . . .



there is a very simple circuit for 8MHz crystal but (it requires less energy for startup) and it also works only with very narrow range of the supply parameters -- so -- it can't be simply adapted for 32k
. . . ?amazingly i've already proven it otherwise ???

8MHz ::


the C14 caused pulsation is likely causing and the instability in the 5v experiment above ↑↑↑↑

32kHz ::


Low NRG 32k ::


Ultra-tuned UHF ::

nearest match from web
http://www.nutsvolts.com/magazine/article/bipolar_transistor_cookbook_part_5



The failed but extremely fast starting UHF resonator Osc. experiment



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Tuesday, March 20, 2018

Synchronours Double Quadrature Osc.


Notice the difference in the bottom inverters' biasing

v.2 :: Lo-Frequency





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Monday, March 19, 2018

testing out the custom xx78L05xxx variant

amazingly -- worked from scratch -- no matter the blind guessed j-Fet and Zener values and much randomly chosen 2N2222 and 2N2907 for "tech."

but the OUTP voltage little drifts with INP voltage and the fold-back (from140mA) starts to work from 14V external supply ( ? wrong zeners . . . )

the model is currently adjusted to 5.0V at Abs.Max 35.0V input

as usual the component level model (78L05) is more stable than the .cir net-list model ( LT1761-5 )


NB! Not all the plotted parameters are relevant/consistent with the ↑↑ shown test
(they are relics from another grid that was used as a draft for these ones)

"Level 2" ::

. . . with custom LM324 CLM ( Component Level Model ) (( which i also needed to test ))


This is why the net-list models are not good at complex circuits ↓↓ (i actually didn't expect to get it "stable" . . .)



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Sunday, March 18, 2018

web buck-boost to custom (Spice-)experimental boost

src.::
mod.::

PS!!! -- Not proofed for startup or for a specific situation switching errors such as (switching fades or changes to too long cycle length = too high current through MOSFET . . .)

-- also it likely can be converted for better efficiency (87% - - might include and some conceptual changes next to just adjusting the inductor and frequency values)

-- target parameters INP : 5V (up to Lim.) 1.5A ; OUTP : about 12V (up to) 200+some mA

 


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Sunday, March 4, 2018

"LM301" test 2

Offset test ::
(was even "passed" to my surprise ? ** is a good Op Amp after all)


However since it's frequency capabilities set it more to audio range - a random internet bootstrapped Op Amp circuit test ::
((this is actually a good - better than expected - result . . . again! **))



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Friday, February 16, 2018

prev. -- follow up

Stage.3 ::

no differential test yet . . . // now is ↓

 

Update! : 2018.03.04 -- Stage.4 ::

. . . Some clean-up ↓↓


After frequency pass ↓↓


In the old soviet literature it is said to be a good Op Amp ???
. . . for audio frequency operation ... perhaps ???

TEST ↑↑ TEST ↑↑ TEST


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Thursday, February 15, 2018

Yet a next attempt to make sense of the LM301

tThe experiment . . . adapted from :: National Semiconductor Corporation , SGS-THOMSON Microelectronics , Linear Technology Corporation , . . .


Still performing some 10x 5x worse than the d/s suggests . . .
-- but there is improvement since the prev. TEST

Related parts ::
  1. http://www.chipinfo.ru/dsheets/ic/153/ud2.html (LM101)
  2. http://www.chipinfo.ru/dsheets/ic/153/ud6.html (LM301A)
  3. http://www.chipinfo.ru/dsheets/ic/157/157ud2.html (dual LM301)
  4. http://tec.org.ru/board/k553ud2/93-1-0-2179 (LM301)

"Stage 2" ::
(compare → https://ocw.mit.edu/resources/res-6-010-electronic-feedback-systems-spring-2013/textbook/MITRES_6-010S13_chap03.pdf ←) the offset and operation of amplifying cfg. is unreasonably critical to R26 value -- if this is to be "normal" then tuning the real Item to work does not pay off using it instead of LM358 etc. + it's gain seems to vanish fast at higher frequencies (at transient pass even when driven to 10k load ??????) . . . as already said this thing only reacts on control currents R29,-6,10,12,3 -- even if i succeed to match this to d/s ?? will the real thing ever perform that good (not mentioning the wrong/misleading/"of a zero help" schematic diagrams on d/s-s) ... it is better to make your own poor op amp that you know how to tune than keep guessing what this thing suppose to be , how it suppose to perform/work , did it work in a first place (as in a sense of today's op amps)

"Stage 2.a" ::
-- the prev. "Setup" even verifies for 25kHz 12 to 42 V tot supply ???

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Monday, January 8, 2018

Regulated single 1.5V AA Led Flaser Concept


there are different 2N3904 models the ones with 100mA I.F and the ones with 150mA I.F -- in REAL implementation of this circuit you may need to multiple parallel these for a switching transistor or use a more powerful low U.CE type one


PS! this is a simulation experiment - the real circuit and components for a similar output parameters may somewhat or significantly differ of those shown in the fig. !!!

about & how we got ↑there↑ ::

initial circuit
the op amp regulation promises worse results than the transistor regulation on the first figure

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