Processing math: 69%

Friday, September 9, 2022

Re deriving formulas for the quadratic eq.


x2+ax+b=0|a=2sx2+2sx+s2=s2b(x+s)2=s2b

x+s=s2bx=s±s2b|s=a2x=a2±(a2)2b


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Wednesday, June 15, 2022

re-worked the formulas for the OC(OD)/OE voltage comparator's resistive output delimitter


an arbitrary output range ver. of the below a related post + the formulas for the non supply median centered output limit :

IC=VLR3  R3=VLIC , def. : χ=R3(1VL1VH){VH=VSR1R1+R2=VS11+R2R1VL=VSR1||R3R1||R3+R2=VS11+R2R1||R3=VS11+R2R1(1+R1R3)

{VHVS(1+R2R1)=1  R2R1=VSVH1 ... =VSVL1R1R3+1VLVS(1+R2R1(1+R1R3))=1  R2R1(R1R3+1)=VSVL1  R1R3=VSVL1VSVH11 

 R1=R3(VSVL1VSVH11)=R311VH1VS(1VL1VH)=χ11VH1VS

R2=R1(VSVL1)=R3(VSVL1)(VSVL1VSVH11)==R3(VSVL1VSVH+1)=R3VS(1VL1VH)=R2=χVS


---==≡==--- Do NOT mix the formulas from the above with the formulas from the below ---==≡==---


• a Supply median centered output limit ver. -- Some definitions :

VS=VCCIC=ISNKVH=R1R1+R2VL=R1||R3R1||R3+R2IC=VLR3R3=VLIC=VSIC11n2

R2R1=α=VLVH=n1n+1=R1||R3R2=(R1R3R1+R3)R2=11+R1R3  R1=R3(1α21)=R34n(n1)2 R2=αR1=R34nn21

• (↑ You only need to provide VS , n , IC ↑ ,  anyway - ) Some more definitions :

VL=VSVH , 1n - is the dynamic output-range around the supply median --e.g.-- the 1 n-th of the total supply

{VHVLVS=1n=R1R1+R2R1||R3R1||R3+R2=11+R2R111+R2R1||R3VH+VL=VS 1=11+R2R1+11+R2R1||R3

{1+1n2=11+R2R1=AR1A=R1+R211n2=11+R2R1||R3=BR1||R3B=R1||R3+R2R1||R3=11R1+1R3=R1R3R1+R3

R2=R1(1A1)=R1n1n+1==R1||R3(1B1)=R1R3R1+R3n+1n1R2=R12R3R1+R3=R11+R1R3

• More backwards extending definitions :

{1A1=2nn+11=n1n+1=α1B1=2nn11=n+1n1=1α{VHVL=VSnVH+VL=VS{VH=VS1+1n2VL=VS11n2

{VL=VSR1||R3R1||R3+R2=VS1+R2R1||R3=VS1+1α=αVS1+αVH=VSR1R1+R2=VS1+R2R1=VS1+αVLVH=α

• About αFn.of(n) :

{VHVL=VSnVH+VL=VS{1α=1nVSVH1+α=VSVHn(1α)=1+αn=1+α1α

nnα=1+αn1=α(n+1)α=n1n+1


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Friday, October 15, 2021

(scheduled) derivation of the solution of the quadratic equation


 about (scheduled) :: every now and then (not too often) i set myself to re-figure it out (the history has proven there exists a variance of what i come up with each time ...)

... so -- Def.-s , etc. ... ::

(xa)(xb)=0 x2(ab)x+ab=0 x2+px+q=0x2+2px+p2=pxq+p2 |×3x22px+p2=3pxq+p2 |+ 4x2+4px+4p2=04q+4p2 |3p24x2+4px+p2=p24q |÷4x2+2p2x+(p2)2=(p2)2q x2+2p2x+(p2)2=(p2)2q(x+p2)2=(p2)2qx=p2±(p2)2q

... (it) came out double ((at) this time) -- the short and the long -- way to (the solution) F;T
// is likely ↑↑ why ↑↑ in many blogs folks do not get a thing what i say
// (as an old school programmer i always live-compact my code(read: text))

see also the inner properties of @ About the Quadratic Equation


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Friday, August 20, 2021

Dif. Hi-Gain Amp. (not very practical)


Vb=VZ+(VnVZ)RgRg+RS

Va=VS+(VpVS)RgRg+RS

Def : 1RX=1Rg+RS+1RP==Rg+RS+RP(Rg+RS)RP

Vn=VZ+(VOVZ)RXRX+Rf

Vp=VS+(VRVS)RXRX+Rf

V_b=V_Z+\left[{\cancel{V_Z}+\left({V_O-V_Z}\right)\frac{R_X}{R_X+R_f}\cancel{-V_Z}}\right]\frac{R_g}{R_g+R_S}=V_Z+\left({V_O-V_Z}\right)\frac{R_X}{R_X+R_f}·\frac{R_g}{R_g+R_S}

V_a=V_S+\left[{\cancel{V_S}+\left({V_R-V_S}\right)\frac{R_X}{R_X+R_f}\cancel{-V_S}}\right]\frac{R_g}{R_g+R_S}=V_S+\left({V_R-V_S}\right)\frac{R_X}{R_X+R_f}·\frac{R_g}{R_g+R_S}

V_S-V_Z=\left({V_O-V_R+V_S-V_Z}\right)\frac{R_X}{R_X+R_f}·\frac{R_g}{R_g+R_S}

\boxed{\quad A_V\quad}=\frac{V_O-V_R}{V_S-V_Z}=\left({1+\frac{R_f}{R_X}}\right)\left({1+\frac{R_S}{R_g}}\right)-1=\cancel{1}+\frac{R_f}{R_X}+\frac{R_S}{R_g}+\frac{R_fR_S}{R_XR_g}\cancel{-1}=

=\frac{R_gR_f+R_XR_S}{R_XR_g}+\frac{R_fR_S}{R_XR_g}=\frac{R_fR_S}{R_XR_g}\left({\frac{R_g}{R_S}+\frac{R_X}{R_f}+1}\right)=

=\frac{R_fR_S}{R_g}·\frac{R_g+R_S+R_P}{\left({R_g+R_S}\right)R_P}\left({\frac{R_g}{R_S}+1+\frac1{R_f}·\frac{\left({R_g+R_S}\right)R_P}{R_g+R_S+R_P}}\right)=

=R_f·\frac{R_S}{R_g}\left({\frac1{R_P}+\frac1{R_g+R_S}}\right)\left({\frac{R_g+R_S}{R_S}+\frac1{R_f}·\frac1{\frac1{R_P}+\frac1{R_g+R_S}}}\right)=

=R_f\left({\frac1{R_P}+\frac1{R_g+R_S}}\right)\frac{R_g+R_S}{R_g}+\frac{R_S}{R_g}=\boxed{\quad\frac1{R_g}\left[{R_f\left({\frac{R_g+R_S}{R_P}+1}\right)+R_S}\right]\quad}=

=R_f\left({\frac{1+\frac{R_S}{R_g}}{R_P}+\frac1{R_g}}\right)+\frac{R_S}{R_g}

\frac{A_V-\frac{R_S}{R_g}}{R_f}-\frac1{R_g}=\frac{1+\frac{R_S}{R_g}}{R_P}

\boxed{\quad R_P\quad}=\frac{1+\frac{R_S}{R_g}}{\frac{A_V-\frac{R_S}{R_g}}{R_f}-\frac1{R_g}}=\boxed{\quad \frac{R_g+R_S}{\frac{A_VR_g-R_S}{R_f}-1}\quad}


about :

Uses the LM324 transistor model (the simulation)


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