thanks for your answer, if i'm right i(t) is an input for the relay with hysteresis and the output is indeed (almost) a square wave for a sinus input. so this is what i'm looking for, but i have a few questions about it.

why is there diff(i(t),t)=sin(t) and not just i(t)=sin(t) as input?

this model is indeed part of a lager simulation, it about a driven pendulum with damping and swinging above a magnet.

where the relay with hysteresis should present the magnet. this relay has the position as input, that is of course the solution of the DE of the system. here is the DE, where R is the output of the relay.

DE:=diff(x(t),t)=y(t), diff(y(t),t)=-gamma*y(t)-beta*x(t)-aplha*x(t)^3+DF+R

i'm not sure if i can implement ihys(t) in this DE?  maybe R=ihys(t) and i(t)=x(t) and diff(x(t),t)=y(t) ???

the first try did not work...

(I'm using also dsolve to compute the solutions)

thanks for your answer, if i'm right i(t) is an input for the relay with hysteresis and the output is indeed (almost) a square wave for a sinus input. so this is what i'm looking for, but i have a few questions about it.

why is there diff(i(t),t)=sin(t) and not just i(t)=sin(t) as input?

this model is indeed part of a lager simulation, it about a driven pendulum with damping and swinging above a magnet.

where the relay with hysteresis should present the magnet. this relay has the position as input, that is of course the solution of the DE of the system. here is the DE, where R is the output of the relay.

DE:=diff(x(t),t)=y(t), diff(y(t),t)=-gamma*y(t)-beta*x(t)-aplha*x(t)^3+DF+R

i'm not sure if i can implement ihys(t) in this DE?  maybe R=ihys(t) and i(t)=x(t) and diff(x(t),t)=y(t) ???

the first try did not work...

(I'm using also dsolve to compute the solutions)