Professor X is an acclaimed academic scholar. While maintaining a busy work schedule, he often forgets trivial daily tasks. For example, he forgets to turn off the iron every morning before leaving home for work. A hot iron left for the whole day can cause house fire and injury of the other family members. Hence, he decided to integrate a small motion detector circuit inside the iron. When no motion is detected in front of the iron, a timer circuit will be activated and turn the iron off after 45 seconds. (a) Draw the block diagram of the overall project. (b) Write the name of the timer circuit (c) Draw the circuit diagram without showing the details of the internal circuits blocks of any IC. (d) Calculate the values of the passive circuit components used in his circuit. [5] [5] [10] [15]