another inductance meter concept

a dummy sine generator :

Op Amp version :

the x = Δf( L( f ) ) = – 2 · Δf / ( (2π) ²­ · C · f ³ )

where Δf = f(40uH) - f(42uH)

the  y = ΔL( f ) = L(42µH) – L(40µH)

and the best match for the ΔL is a non-std. average E( x , y ) = 2 · x · y / ( x + y )

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High Immunity Logic - web circuit mod.

src. ::

Simulated with the zener  and it's substiute

The substitute

Update for wider supply range -- with "doable" alternate for the questionable (6.2V) zener -- questionable as ? does it actually behave as it simulates . . .

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BjT versus OpAmp Staircase Generator

src::GE Transistor Manual 7-th ed. 1964 p.345
about :: it takes higher energy pulses + a NEG supply to run , (it may be not so as i quite don't get yet the anatomy of the thing but) it seems to have a worse linearity than the OpAmp v. though it also seems to keep it's levels longer in place and have a smaller variation in step size near zero to near Vcc (to "Zero the drift" it takes somewhat unreal precision tuning of the bias resistors . . . )

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PS! -- The RESET circuitry is NOT implemented for neither one of the gen.-s -- coz it'd result in slower simulation times - and it should be relatively easy to set up one for your needs
. . . also the use of low power oscillator requires a buffer 1 to not be affected from the fast-/"a low resistance value" -biasing resistors' reaction/(?bwd coupling)

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src::http://zpostbox.ru/g4_e.htm (Fig.28)
about :: the OpAmp v. accepts a higher variety of pulse voltages and tank-/integrator capacitor values -- the linearity is likely better than for bjt v. also the integration range is bigger (due lesser possible pulse amplitude values and the possibility to drive OUTP (Vsc) more close to upper rail . . .)

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LM324 versus LM308 -- MM versus CLM

LM324 versus LM308 -- Macro Model versus Component Level Model

In small signal range the LM308 (an older design 1969) seems to have a half faster response than the LM324 (a newer design ?1972?)

signal shape dependency on input amplitude ::

the particular apx.-n of LM324 CLM is not too exact (but in some tests shows out a better performance than it's factory provided macro- (a "net list" .cir) model)

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Progressive current limiting

Figures ::

Legend :: opamp.Q1 mirrors the current at R5 , opamp.Q2 limits the current progressively ... and incase of the SC it cuts the output the more off the lower is the output voltage -- so there's double level progressive limiting (the fig.2 shows the 1-st and the fig.-s 3 to 5 show the 2-nd - a short circuit - limiting levels) . . . the resistor values for R24 to R26 and R21 , R22 , also for the R14 may need to be adjusted to get the real build of the circuit stable (maybe it takes more adjustments -- but these are known to be more likely critical at this stage of dev.)

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regulated switched LED regulator designs (experimental)

the thing ::

how to set it up in practice . . . involves a number of tests ::

1. Detach the mosfet and the feedback Mod line -- from simulation and from build
   Regulate the frequency and duty to match those of the simulation
2. Re-attach the mosfet , ( /!\ /!\ /!\ ) set some 20Ω or greater in series with the 6LF22 to limit the current through LED-s --and-- set electrical fuse or limitting resistor in series with the LED-s --or-- double the number of LED-s ( /!\ /!\ /!\ ) - - - - - - - - - we are going to verify the transformer ::
   do the same mods on the simulation and test for the differences . . .
   -- if the real build performs worse you need to recalculate and rebuild the transformer accounting for resistance not present in ↑this↑ circuit
   -- if the build performs better then the primary side is "over-driven" the timing of the switching wave-forms has to be re-evaluated and adjusted
3. Attach the Mod line --and-- ( /!\ /!\ /!\ ) set the regulation to be greater than in simulation (!! dont remove electrical fuse or extra LED-s !!) ( /!\ /!\ /!\ ) ,
   -- regulate it bit below the desired LED current (in case the regulation failure -- the regulator has to be re-designed --or-- replaced with better known one)
4. if everything worked out so far the additional tests are required such as ::
• test for bit higher than simulated input voltage (the Cl batteries may have up to 1.8V per cell e.g. 10.8V for fresh 6LF22)
• test for battery contact strobe !!!
  -- here everything can fail -- use fuses and perhaps build a protective controller that can fast switch off the circuit under test
• test for the lower than in simulation input voltage !!!
  -- may result in oscillations failure and the MOS-FET being "constantly ON" (attempting to remain in conduction mode) . . .
• etc. ...

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Basic simple ::

add VCO , Mod2 divider , the 2 to 4 decoder and a current sense / +integrator -- and it's basically done . ..

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Comparing Different 6LF22 to +5V supplies

Circuits ::

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Cross Ref. ::

Param.	100	110	120	122	124	128
Description	Pos. collector-load linear-reg.	Pos. collector-load linear-reg. with fold-back	Pos. experimental Op-Amp regulated collector-load linear-reg.	Neg. j-Fet - emitter-load linear-reg. with fold-back	Pos. emitter-load linear-reg. with current lim.	Pos. VF-PWM buck conv.
Average Efficiency	51%	53%	57%	38%	28%	83%
Short-Circuit Current	120 mA	1.7 mA	NOT Ltd.	2.6 mA	* 57 mA	NOT Ltd.
Voltage Regulation	± 600 µV	± 250 µV	± 300 µV	± 15 µV	(± 550µV)	± 54 mV
Output Current : Nominal (Max.)	80 (85) mA	80 (145) mA	80 (150) mA	50 (105) mA	* 50 (54) mA	200 (>400) mA

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Source Circuits ::

↑↑ src :: ISBN 5-440-00345-2

↑↑ src :: GE Transistor Manual 1964 ↑↑

↑↑ found from :: LED Torch Circuits ↑↑

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9V-to-5V Step-down concep design

the thing

switching wave-forms at max.-min. load

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revised the yy78Lxx 5V variants

tests so far ::
PS! -- although the following setups perform well the real tings may not coz the Spice models use highly accurate fixed current sources - - - while there's no indication the real 78Lxx-s had any implemented //// the last time i tested my real 78Lxx-s showed an ulta poor performance where the voltage started to drop already at !!!above 30-/40 mA drain and significantly differed from the nominal at 50mA (while i didn't notice them getting hot -- so that a possible thermal prot. feature could have had engaged ???)

partial apx. match to d/s ::

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ADC related Op.-Amp. Experiment

~about

↑↑ _ the best result here however would be Frequency × Slew Rate _ ↑↑

(( required to Drive 74HC14 's INP , AND/OR that relative to a V_REF . . . basically to make power-buffer's input more sensitive & a higher impedance one))

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555-s based SMPS test

as is ...

... in practice it requires a sharper or more discrete response for larger errors -- this one could do for relatively steady load -- a bad point here is that increasing the controls' sophistication impacts either on efficiency at light loads - - - or retail tech. such as in SMPS controllers where the dev. of such is expensive and won't pay off for prototype solutions . . .

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+ an update to the schematic in the prev. post

no pwm just switching test
*

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Web Buck Remake

src. :: http://www.talkingelectronics.com/projects/LEDTorchCircuits/LEDTorchCircuits-P1.html

somehow it did not "work"/simulate too well
???

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experimental/unfinished mod. :: with "pulse skipper" for low loads
/// i have no any idea at this point how one should tune the real circuit into proper operating mode . . .

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K174YH4A audio power-amp. TEST

i just needed to confirm the apx. setup , study a bit about it's pin functions . . .

transient

► the R7 was shown on a schematic as 30kΩ - it very slightly suggested from the output wave form that it might be of a lesser value -- also the value for C5 is mostly intuitive -- since i mostly do DC amplifiers -- i can't confirm nor reject any of these -- e.g -- don't use/distribute this schematic without critical revision / notice about it's TEST status.

+ . . . ?? it seems it's output passes back to it's input so i 1-st reduced the inp.imp. from 10kΩ down to 1kΩ then further to 75 (though it was almost acceptable with 1k ???) . . . yet another d/s about this chip shows the inp.imp. to be GE to 10Ω it's ten ohms - no kilos . . . ??? what kind of an amplifier has 10Ω input impedance . . . as i told i donno much about -- !audio? . . . sh¡t - it is still that kilo ohms e.g. it is 10k (they used insane notation as unit - kΩ , value - scientific , as 10¹ , so i didn't expect the non-SI unit -- while it turned out the exponent ¹ was a pointer to reference text . . . !!! documents !!! documenters ...)

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frequency

??

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re-transient this time with just above 1W ??? 300mW or less for the real chip ("std. derating" factor)

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