Thursday, August 10, 2017

K174YH4A audio power-amp. TEST

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


► 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 ...)


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


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