quand y=0.010000000000, x=0.790199248364 V 
a = 0.901198416038 : b = 0.024888033306 : c = 0.361446129703
x = a + b * Log(y) + c * y 

quand y=0.001000000000, x=0.730388614098 V. 
a = 0.903243335828 : b = 0.025058812577 : c = 0.388536432363 : n = 1.066505416709
x = a + b * Log(y) + c * y^n 

y = f(Vbe) = Beta (Ic/Ib)
y = -331691.940864625 * x^10 + 2469286.874014860 * x^9 + -8210694.197618058 * x^8 + 16057604.055849604 * x^7 + -20454159.442395445 * x^6 + 17732367.256424770 * x^5 + -10596294.825219914 * x^4 + 4310065.352671417 * x^3 + -1142155.818585692 * x^2 + 178079.929015643 * x + -12406.903862595

R2 = 0.999996731
