Extreme temperature changes result in many failures of electronic circuits [1]. Temperature control feedback systems reduce the change of temperature by using a heater to overcome outdoor low temperatures. A block diagram of one system is shown in Figure P4.8. The effect of a drop in environmental temperature is a step decrease in Td(s). The actual temperature of the electronic circuit is Y(s). The dynamics of the electronic circuit temperature change are represented by the transfer function.

(a) Determine the sensitivity of the system to K.
(b) Obtain the effect of the disturbance Td(s) on the output Y(s).
Figure P4.8
Temperature control system.

G(s) = s2+20s + 180 Tis) Heater control Electronic circuit G(s) 0.1sI