Thursday, September 28, 2017

automatic duty ratio control experiment

a definition correction :: the 555 acts as the 555 e.g. an inverting comparator with the high accuracy hysteresis relative to supply rails (however it's internal hw setup is similar to a window comparator namely an "outside the window comparator" - only it's comparators´outputs are not bound together by simple combinatorical (read: boolean algebraic) operation - which for outside the window comparator would be logical sum) - but instead they drive an RS-trigger which inverts the upper comparator output and remembers that output until the lower comparator triggers - then remembers it's output until the upper triggers - which in a sense of a window comparator would be - depending on input slope - an unidirectionally active operation of the pair of inverting and non-inverting comparators . . . the least however reduces to the case of a single comparator with relatively large hysteresis and inverting output

Low Voltage Op-Amps -- in-simulation TEST

(1) -- verifying "std. responce" + "model ok for simulation"

(2) -- relative "performance"

(3) -- Exactness/Speed // Design/Setup

(4) -- capability for specific operation in low-/limited- supply voltage application


Thursday, September 14, 2017

Wednesday, September 13, 2017

LM113 quest for practical use

what it seems by now is that utilizing the potential power of the chip requires the target oriented , also a clever and sophisticated "trick" -- not a straight forward block level design but the one that takes into account the specific nature of the LM113 in this case . . . i yet am to figure out both - the trick and the nature . . .

experiments ::

used as shunting regulator

d/s version
PS! altering the ellipsed values causes the circuit to become unstable/oscillate

combined trivia
used as zener

shared function in feedback chain

not used at all / instead we use positive error feedback here ▼

fast opening non-linear/log. bridge/circuit elements

used as zener -- OR -- if we consider the j-Fet´s V.gate = fn.(I.source) then seeing it upside-down it acts as shunting ref. functionally shunted to Op Amp OUTP or V.gate

j-Fet bridge


Tuesday, September 12, 2017

FW - TL431 LM113 Spice model variants´ TEST

it looks like i already forgot what i graphed
Z=V(voltage point)*normalizer -- sets all references to a default unit value (1V)
relative scaler log10(Z)*relativeNormalizer -- resizes plots so they fit to same scale . . .
. . . so the smaller the "relativeNormalizer" is the worse the device performs (has greater fluctuation range)

so the "Z" re-plotted (for stepped current) ::

 . . . the 1.67V µm 431 variant seems to perform best here in both current ranges (x431/x113)
- - - -


Monday, September 4, 2017

TL431 Spice model variants´ TEST

presented as we go
► 1-st

► 2-nd
► 2-nd - in detail
wider range
component level models (sub circuits compared)
the best - upper two are the attempts to achieve better precision×frequency-rejection //// the reverse Vref´s emitter (EB) diode in Rank#(7) is a contemporary relic from an attempt to force the "Hot Start" for U4,U5 . . .

pulse e.g. stepped load response
overall ranking so far ...
? best CLM-s !!! for static operation . . .
. . . for undefined input the U5 e.g. X4 is likely better choice /// might be quite expensive regulator as the RF transistors cost $ 0.2÷1.0 per pcs.  /// (i can't comment nor recommend nor reject the macro models - but usually they are too optimistic !!!)

hi, hi - UPS! seems i used Amps insted of milli-Amps
that re-ranks the rank back to "Static" -- the red box is "for super cool experiments only!!" . . .
. . . so U2 // X1 the best CLM !!!