Hardware and software
Logic Gates - designing circuits
A chemical factory uses the following sensors in the hazardous mixing room:
- pH sensor : to monitor the pH of the liquid in the mixing tank.
- temperature sensor : to monitor the temperature of the liquid in the mixing tank.
- motion sensor : to detect if somebody has entered the hazardous mixing room.
Using ANALOGUE-TO-DIGITAL converters (ADC), analogue data from the sensors is converted into digital signals and processed by a microprocessor.
The following table describes the digital signals that are generated by the sensors according to the situation in the mixing room:
| sensor | condition | binary value |
|---|---|---|
| ph | <5 | 0 |
| >=5 | 1 | |
| temp | <=28oC | 0 |
| >28oC | 1 | |
| motion | nobody in room | 0 |
| somebody in room | 1 |
Task 1
A digital circuit must now be designed such that the alarm will sound if:
The temperature is above 28oC and there is somebody in the room
Use circuitverse to design the circuit. Be creative - think. Have a go!
Here is a very short tutorial to help you get started with circuit verse.
Task 2
Make sure you compare your solution to Task 1 with the solution. Do you understand it? If so, here is Task 2:
The circuit needs to be redesigned. The alarm will sound if:
The temperature is less than or equal to 28oC and there is somebody in the room
Design this circuit and compare your answer with the solution.
Task 3
Make sure you take compare your solution to Task 2 with the solution. Do you understand it? If so, here is Task 3:
The circuit needs to be further developed. The alarm will sound if:
The temperature is above 28oC and there is somebody in the room
or
The pH level is below 5 and the temperature is less than or equal to 28oC
