6. An assembly line has 3 fail safe sensors and one emergency shutdown switch. The line should keep moving unless any of the following conditions arise:

(1) If the emergency switch is pressed

(2) If the sensor 1 and sensor2 are activated at the same time.

(3) If sensor 2 and sensor3 are activated at the same time.

(4) If all the sensors are activated at the same time. Design and implement in visual spice.

Suppose a combinational circuit for the above case is to be implemented only with NAND Gates. How many minimum numbers of 2 input NAND gates are required?

ans:

A = Switch B=Sensor1 C=Sensor2 D=Sensor3 Pressed or sensor activated = 1 F=Shutdown=1