clc;
R1=27*10**3;
R2=56*10**3;
C1=0.01*10**-6;
t2=0.7*R2*C1;
t1=0.7*(R1+R2)*C1;
T=t1+t2;
f=1/T;
disp('kHZ',f*10**-3,"f=");
t=(0:0.1:6*%pi)';
plot2d1('onn',t,[squarewave(t,60)]);