Question

You have been hired to design a control system for a nuclear reactor. The system monitors the temperature of the reactor using sensors at two points, A & C. If the temperature at either of these points rises past a certain level the sensor will toggle high. A sudden blackout would be disruptive so an override lever, B, is installed to keep the plant running when one of the sensors are tripped until a maintenance team can come in. If both sensors trip, the plant will shut down regardless of the override lever. Assume that the output - a plant shutdown - is represented as a logic

Assume that it takes only one sensor to toggle high for the plant shutdown if the override lever is not activated. Assume B=1 indicates the override lever has been activated.
Construct the truth table for the control system.

Answer 1

B A C Shutdown (V)

0 0 0 0

0 0 1 0

0 1 0 0

0 1 1 1

1 0 0 0

1 0 1 1

1 1 0 1

1 1 1 1

`$Y = A + A\bar B \bar C+\bar A \bar B C$`

`$Y = \bar B A C + BAC+ \bar B A \bar C + \bar B \bar A C$`