A Shifted Clock PWM test on 555 timers

the circuit ::

basically we have something here that resembles to a PWM but the circuit has several shortcomings

1. a bad selection of control voltage ranges that won't allow us to get intended PWM/delay control
2. while the clock generator is about independent of the supply voltage then other timers are not
3. the operation relies on successful fast cascaded triggering of the timers -- this might set a speed limits or other wise complicate the circuit

otherwise this DEMO is likely sufficient to give the reader a clue about what was intended -- AND-ing the shifted clocks at low duty versus OR-ing the clocks at high duty ---

--- the 0 to 100 % PWM is achievable either by designing the delay-/shift- timer to enable very narrow delays or pre-scaling it's start by it's time minimum constant -- adds complexity and degrades the accuracy and/or reliability

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A different approach -- using a simplified setup -- and more complex special situation handling ::

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Testing couple of rectifier circuits from datasheets

The following schematics are from LT1122 and LTC1047 d/s-s
while the first performs more than good -- then on a contrary i had to modify the 2-nd

↓Src::LT1122 datasheet -- not tested at various frequencies nor input amplitudes/wave-forms
 

↓Src::LTC1047 datasheet -- the 10kHz seems to be the limit for the outp integrity here

//// recently i noticed something while using a variant of the ideal diode circuit as shown in the "Low Voltage Op-Amps -- in-simulation TEST" -- so i am about to test through all "Absolute circuits" for their particular peculiarities . . .

↓Src::NE5535 datasheet

↓Src::http://nptel.ac.in/courses/117107094/17

↓Src::https://www.planetanalog.com/author.asp?section_id=3065&doc_id=562650 -- the circuit can do just at about 200kHz !? //// note :: i forgot to change the counter-weight 1N4148-s to 1N34-s below (their effect is not studied here , purpose = pending -- what seems obvious is not always that -- it must be verified whether there should be counter-balance for rectifying diodes or not . . .)

↓Src::https://forum.allaboutcircuits.com/threads/a-full-wave-precision-rectifier-query.9821/ --

↓Src::http://sound.whsites.net/appnotes/an001.htm -- it can go up to the limits defined by the frequency & slew of the Op Amp in use ((!? amazing circuit ?!))

↓Src::http://www.learningelectronics.net/worksheets/opamp8.html --the ® had a "bug" so i made random guesses . . . came out as good as previous ((at least what it seems so far ?)) /// edit : the R9 should be Rcp (although there seems no significant current to/from GND from/to U2.non-inverting_input) /// the input signal amplitude range is ±1.8V @ ±5V supply and ±10V @ ±15V supply -- simplified to a line equation y = ax + b where a = 1.219512195 , b = 2.804878049 , y = VsupTOT/2 , x= abs(±VmaxINP) referenced to the GND ( = Vsup "median" )

updates 'll follow ...

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LM317 component level versus LT317 macro model

about the real things LM317x LT317x

simulation models (Custom against Linear)

a curious thing ↑here↑ is that the CLM(component level model) seems to be more stable than the ↓next↓ macro (more simplified) model

Models about ::

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Re: Op Amp "Internal ground"

perv. v.

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Low Voltage Constant Current @ ~1V

the two power opting v. are present (Left , 1-st & 2-nd) on all 3, sets for comparison

(A) -- tested using Ge bjt-s but they appear to require relatively high BE voltage to output any significant current -- PS! -- it just might be due to poor spice models -- if not -- the Si ones perform better coz higher ß value !?

(B) -- multi-device experiment ??? -- PS! -- the depletion mode mosfets and their active resistance likely cause a complex regulation curve

(C) -- basic simple . . .

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