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


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 . . .


Wednesday, April 18, 2018

prev. follow up

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


Monday, April 16, 2018

examining a couple of web variable gain amplifier circuits


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


2018.04.18 -- Update ::

bipolar v. of the previous

integrated analog multiplier substitute for VGA


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


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


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

a tuned (this time) j-Fet amplifier stage


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

The failed but extremely fast starting UHF resonator Osc. experiment


Tuesday, March 20, 2018

Synchronours Double Quadrature Osc.

Notice the difference in the bottom inverters' biasing

v.2 :: Lo-Frequency


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" . . .)


Sunday, March 18, 2018

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


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



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! **))


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 ???



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. (LM101)
  2. (LM301A)
  3. (dual LM301)
  4. (LM301)

"Stage 2" ::
(compare → ←) 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 ???


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