Monday, December 28, 2015

Virtual Ground tracking circuit

? I 1-st thought it´s impossible . . . but it like does something

. . . it sums the wrong trace !!! voila !

here´s a modified v.

and that´s more like it F;Y


Sunday, December 27, 2015

a flip-flop experiment

a ? "T-trigger" from two NAND gates ::

►► the idea behind it was to use a half of 7400 for one "pulse driven RS-JK-trigger" . . . which might be the case if this thing can be opt-/minmized to a lesser component count (total design/build-cost) and made a lot more noise immune (can be operated in realistic env.) - it will start to oscillate if it´s shoulders components won´t match too well (which means almost precisely) -- here i just found the reasonable upper frequency limit for (about 44MHz for inp.-clk.)

the Q0 , Q1 are inter-coupled to get high-fq. readout - with lesser frequency there´s no need to couple them - and originally they were added to confirm the valid readout can be had from K and/or M gates -- so , the fast ver. of this trigger requires the full 7400

. . . just had that question


Saturday, December 26, 2015

Adjustable duty/frequency OpAmp Oscillator

1-ce you get customized with these things (OpAmp-s) - they're nifty to use for all sort of tricks -- the below design was chosen due it's adjustability × lesser number of components compared to it´s TTL or CMOS variant

 the interesting point to note here is that the КР140УД1408 : LM308 specify their lowermost supply range at ±5V(+10V) : ±2V(+4V) respectivly -- while the voltage buffer/-follower configuration still works with +5V for КР140УД1408 without any fq. compensation ??? here´s the component level model of neither* УД14 nor LM308 OpAmp-s exactly (*also coz "we" don´t know the exact transistors used in the actual thing -- nor does the circuit exactly match neither -- about What? = it's close enough to simulate both (only some 10% of Spice simulations hit the real life - the small alterations to OpAmp model won´t significantly change that figure))


yet another LDO 5V regulator

the Regulator :: /̲!̲\̲ this thing seems to perform better than LE50A (STMicroelectronics) , LM78L05ACM (National Semiconductor Corporation) , MC78L05AC (Motorola, Inc.) /̲!̲\̲ when powered by 9V 6LR61 alkaline -- in a sense of IOUT/ΔUOUT . . . . . . . . . history of :: the goal : steady supply for OpAmps powered from Lo-Power battery ►► everything is good as long as you have to implement the current limit . . . so this one has 1 unintentionally "built in" (adjustable by transistor-switch current source) ::

the actual transistor used for switch is ancient 2SD1252A (Panasonic)the custom zeners are random Red-LED + Д9К (apx. 2V + 320mV drop) other BJT-s are 2N3906(-04) but you can use a better ones such as fixed beta 2SA1015 , 2SC1815 ...

!note  :: altough theLE50 is labelled as "Very Low Drop" it actually performs worse than 1 of those 78L05-s and the all three b_a_r_e_l_y manage the 150Ω load with reasonable output (4.8 dn2 4.7V) . . .
 . . . when the brought regulator does 100Ω with about 10mV output-drop and acts similar to above 3 at about 26Ω with 175mV drop e.g. 4.83V output -- though /̲!̲\̲ it does not have thermal protection and it's current limiting is poorly studied /̲!̲\̲


Thursday, December 17, 2015

theoretical wall ~AC line detector

since there is reason to believe the ®´s j-fet input stage rather attenuates than amplifies
the E - field variations i set up a simple band-pass based 1 ::

this might still require extra input stage (for deep buried wires)
+ experiment with the layout , sensor , 3-sholds´ sensitivities before we can say if it´s for any good

updated an old Sq.-wave oscillator to a voltage controlled one -
to be mixed with prev. ~50Hz output ::

it is good to pre-test and choose + adj. the optos to the same transfer ratio ,
everything else shouldn´t be too much trouble ?


Tuesday, December 15, 2015

Single v. Double Op-Amp "Rectifier"

Intuitive design ::

Modified from the book ::

/̲!̲\̲ "Ideal DIODE" /̲!̲\̲ ::

e.g. below 24k ÷ 2 = 12k Hz (Dbl v.) OR 2k ÷ 2 = 1k Hz (Sng v.)


Thursday, November 26, 2015

an Op-Amps based "Proximity detector" + alternate sine generator

my 1-st concept of proximity detector ::

too many components for flame (color temperature (rainbow)) Christmas lights ::


B4:A4:Y4:X4 -- Red:Green:Blue:Red (!!! a color for the Flame effect -- not generated by this circuit . . .)

using switching and level hold the number of chains reduces to one -- it still might be more practical to use AD and DA converters with digital function generators (?EEPROM) , level hold switced output to gain the voltage 2 color effect of your like ... or use 4 differently biased optos or use a fine adjusted PNP NPN chain (cost efficient) , e.c. . . .

the varying color predecessor of the previous -- an alternative sine generator ::

drawing (supposedly) only 125µA from the 5V source


Tuesday, November 10, 2015

alternate for gas discharge indicator

((fuck this blogger *editor is slow 2day . . . ))

so about :: i've made (now a total) 3 circuits that use active pre-load - all have failed due a different reasons

(i) using ~250V electrolytic capacitors in series with incandescent lamps -- the ´lytes exploded !!! (trivia) -- however it took them 1.5d (some 36h) to heat up -- later i just added more incandescents to fill the voltage gap

(ii) using ceramic capacitor before Russian Lim.?700V full-bridge . . . that actually has a std. leak - e.g. if [+][–] terminals are not connected the –[L]] –– [[~] Bridge [~]] –– [[]Load[]]––2 [[N] – connection provides enough AC for 25W incandescent as a Load to glow near it´s max brightness !!! --- everything worked correctly at nominal !!average!! values (measured by analog multimeter) but the LED and 1BJT failed after 1.5y (apx.13000h) ???

(iii) using 15nF as "200kΩ" pre-load to 60V neon lamp caused the neon´ to relatively fast dim down and collect eighter C or metal film to it´s inner surface causing more dimming (service apx.1500 + ? h)  . . .

. . . so i replaced it with this ::

( it´d make sense to set at least 1 fuse close to [L] or (2-nd near [N]) terminal -- this circuit relies on 10A line protection -- i can't predict how warm the (250mW) 100 ohm limit´ll get in continuous op. and what results if it does heat up . . . )         Update/About -- (so far it does not give out any smoke) but one LED is brighter the other one -- is either the asymmetry of DB3 , a bad selection of capacitor values/ratios -- or a combination of both (some of it can be adjusted by discharge resistors , charge storage cap.-s) . . .

((the Blogger* didn´t crash so far !!! . . .))


Friday, November 6, 2015

Couple of OpAmp experiments

FF(fixed frequency design) apx.~50Hz 3-ph ((another) alternate (for a)) Sine generator

V2F experiment (poor -- attempting to grasp some principles)


Tuesday, November 3, 2015

Couple of new CCS tested

b) the LT1112 reads " ... Picoamp Input" ((i wonder what they mean by that)) anyway it's used here (not as initially planned)

a) almost no change to something already multiple tested but still new

a) compared with oldies ::


Monday, October 26, 2015

Common-Emitter versus Op-Amp (prev. follow up)

>>> it's the common head ace with Lo-Pwr signal source - not to kill the signal / - stop the oscillator

CE is more susceptible to supply & Op.-Pnt drift in noisy env. ::

Opa. is all fun to get going (fast, in phase) . . . -- do the right thing ::


  • inverter test concept
  • 2 types of pulse generators
  • 1W chaos from fixed +5V

--- shortly -- i built an intuitive transformer to test the solar battery charger design . . . then i attempted to figure out how to drive it somewhat reasonably ---- the op.-g range for following is unknown ---- not speaking of special design for hi current high fq. pulse transformers F;X F;X F;X

the pulse generators are required everywhere not only solar-battery inverters ... so i revisited an old concept

. . . and figured out sort of a complementary v. for it
v. (A)

v. (B)

. . . and a chaos generator - though quite efficient by simulation
v. (C)


Thursday, October 15, 2015

fuzzy science of extending the range of 3-terminal (fixed) voltage regulator

Bew , here we go  . . .
  • in case of ringing inc C2 then C6 then (C8,C7)
  • R10 , C8 (, R8) -- lobe ass filter
  • R11 , R7 -- Vtg. Div.-r
  • R13 , (R3 , R14) -- Regulation logic
  • (R15 , R17) , (R18 , R19) -- fine tune level shift (enabled by R3 ≠ R14)
  • /!\ There is no SC protection (use fuse or you'll loose your device) /!\
. . . it seems the "std." v. of the above has the same error of apx. ±400µV ---- so i added a secondary error correction

the remaining op amp from ´1366/-7 can be used in a separate supply for opamps or electrical-fuse for short circuit , e.c.


Wednesday, October 14, 2015

a Collector load (sc proof) Vtg. Regulator

since the component countfor this bullsh¡t

is higher and it has an error to the range
 of the following (! not built / tested -- but i guess it's not far from it´s actual)

then i guess i gonna get this 1 PCB-d and cased in with an appropriate ( 300+mA @ 10V DC ) transformer , damn it takes long to test out what you actually need and that actually works as designed -- should've brought a random 600÷1000mA 9V SC proof linear reg. such as KA7809

Update !

now more precise v. of the above is available


Friday, October 9, 2015

DB3 tester (practical)

updated my Spice DB3 alternate . . .

. . . the fuzzy thing is -- i donno why it works -- Link to ◄◄ use at your own risk

Tuesday, September 29, 2015

How to kill your LDO

extends ,

Getting some numbers . . .
a quick fix + improved zener
(*update :: i used in practice a darlington - not the super ß - "power switch" - this cfg. seems to have a better supply-/load rejection than below ↓↓)

insane . . . improving Vs rejection + "digital" current limit

"back to analog" -- adding batteries . . .
 (*update :: see above ↑↑)

(hope idon't uploadthis2wce) -- a fold-back sc current Lim.

Monday, September 7, 2015

another CMOS 32k osc.

. . . a lot of head ace to get to this in simulation (i wonder how the "textbooks" promote such a big number of the simplified versions of that kind of oscillator - some of which actually even simulate but with insufficient output amplitude ??? ...  ,  near/above 1MHz X-tals likely have lesser issues)

the src.


Monday, August 17, 2015

another 32768cps osc.

the resistor values can be varied** from R.c ~50k(perhaps less) ÷ 4M Ω , increasing the X-Tal coupling capacities (keep Qz→Base > Qz←Collector better result in most cases) boosts startup also degrades waveforms , increasing R.e shunting capacities gives better fq. responce below the target fq. (it likely dosent boost startup) , adding C-R chain from base to ground kills some unwanted amplification ? improves waveforms especially I.qz ? adjusts/stabilizes the osc.fq. (it takes a lot of playing around to specify the type of oscillator better - i just found such frustrating at this time) -- the main point -- it uses trivial & flexy range of capacities !!! ((if you dont much change the C8,9,2 - the operating power / other component values  - can be widely modified**))

the prev. v.-s ::
32768kHz Qz-resonator osc. test-dev.

Thursday, August 13, 2015

Random experiments

Opto. usage (digital mode) ::

Sqr.Root circuit ::

Variable Frequency osc.

Active Negative Resistor circuit (src. modified)


Thursday, August 6, 2015

F;x "nothing to do"

LT1635 . . . to be honest - i donno what2-2 with that stuff . . .

. . . i guess i got it better this time than previously

feel free to dump or redesign
 don't feel too 4 however ::x

? . . . R10,13,11 -- a linearization attempt for - supposing - the shunting regulator -- the built in reference can be slightly improved to have no front nor trailing peaks/ringing and to have better supply rejection (by special external network) which i banned however coz it made it's response slower (and it's not so important if stable supply is provided)

?? . . . ??? if i recall right the reference can't be immediately fed to op-amp (causes problems) -- and the op-amp itself tries to start ringing in all possible ways (nothing special -- it just has a narrow conditions for "normal" ?? opreation , baah . . .)

??? . . . i guess the trivial use of this stuff is that you set your reference to 0÷Vs and simply amplify this by op-amp to have ±9(/10)mA voltage source/-reference . . . it seems i've missed that sentence "The reference and buffer combine to achieve a drift of 30ppm/°C, a line regulation of 20ppm/V and a load regulation of 150ppm/mA." . . . ±10mA → max.±6.75mV for 9V Vs.TOT . . . ??? the simulation is typically 10÷1000x better than the actual thing ±15µV → ±15mV =sum. somewhat credible . . .

[end of that bullshit]

Wednesday, August 5, 2015

custom 1.2V logic "ser.-s" revised

what was revised ::
(( not too very good as seen from ))

what we got ::
(( an inverter + additional schmitt 3-ger ))
(( always fun to test new oscillators ... ))
(( basic , simple ))
(( X-Tal type ))