#### koolguy

##### Active Member

O = summing junction with one plus and one minus input

1.) what the use of it??

2.) from where??Gs = G(s) = K/(s*(s+1))

& this

The z transform of G(s) with unit impulse and sampling period of 1 second is:

G(z)=K*(0.36787944025834*z+0.26424111948332)/(z^2-1.367879441171442*z+0.36787944117144)

If the system is stable the roots of 1+G(z)=0 all lie within the unit circle, so

we compute 1+G(z)=0 for various gains.

With K=1 we have:

1+G(z)=0

where G(z) evaluates to:

(0.36787944025834*z+0.26424111948332)/(z^2-1.367879441171442*z+0.36787944117144)+1=0