Question 28 – Boolean logic - AQA Computer Science Questions

An automated safety shutdown system for a chemical reactor is designed to trigger an emergency shutdown signal, $S$ .

The system has three inputs:

$P$ (high pressure detector)
$T$ (high temperature detector)
$C$ (coolant flow sensor)

The emergency shutdown signal is activated if both pressure and temperature are high, OR if the coolant flow sensor is NOT active. This logic is represented by the Boolean expression:

$\text{ AND } T) \text{ OR } (\text{NOT } C)$

A block diagram of the logic circuit representing this system is shown in Figure 1 below, where the gates are represented as generic blocks.

A block diagram of the logic circuit with three inputs P, T, and C, and one output S, using generic blocks for Gate 1, Gate 2, and Gate 3.

Draw the standard logic circuit symbol for the logic gate used at Gate 3.