Transfer Function

Transfer Function

          The transfer function is a mathematical expression showing the relation between output and the input to  each unit or block of a control system. If the system has a single input and a single output, it can be represented by block diagram as shown in Fig., 

Transfer function is defined as the ratio of output over the input with all initial conditions equal to zero. Mathematically, 

Transfer function =  θ0 / θ_i

              Where      θ0 = Output signal of the block of a system, and 

                               θ_i  = Input signal to the block of a system.

Thus, the output from an element be obtained by multiplying the input signal with the transfer function.

Note : From the transfer function of the individual block, the equation of motion of system can be formulated.