Marianville · Grade 11 ICT
Grade 12 · Term 1 · Unit 3 · Technology Systems · Chapter 6

Integrating Technology Systems for Problem-Solving

Week 6 · Benchmark 12.5.1.3 Integrate systems for problem-solving
Essential question

How does a working technology system combine sensors, processors and actuators to solve a real problem?

Learning objectives
  • Draw an input–process–output–feedback block diagram
  • Identify sensors and actuators in real PNG systems
  • Explain the role of feedback in reliable operation

Overview

A technology system takes an input (from a person or a sensor), does some processing, and produces an output (usually via an actuator such as a motor, valve or lamp). The best systems also feed back information about the output so they can self-correct. Think of a rice cooker sensing temperature to switch off automatically.

Input – Process – Output – Feedback

Every technology system can be drawn as blocks. Inputs are sensors or human commands. Processing happens in a microcontroller, PLC or computer. Outputs drive actuators. Feedback returns information from the output back to the process so it can adjust.

Sensors and actuators

Common sensors: temperature (LM35), light (LDR), moisture, ultrasonic distance. Common actuators: LEDs, buzzers, DC motors, relays. Choose them to match the problem — a school gate does not need an aviation-grade sensor.

Case studies

An irrigation controller (moisture sensor → controller → valve) or a security alarm (motion sensor → controller → siren + SMS) both show input–process–output–feedback in one clean diagram.

Activity

Block diagram sprint

  1. Choose ONE of: automatic gate, hostel water tank monitor, school PA system.
  2. Draw the input–process–output–feedback diagram on A4.
  3. Label at least one sensor, one actuator and one feedback path.
Review questions
  1. Name the four blocks of a technology system.
    Reveal answer

    Input, Process, Output, Feedback.

  2. Give one sensor and one actuator used in a school setting.
    Reveal answer

    PIR motion sensor (sensor) and buzzer (actuator), for example.

  3. Why is feedback important?
    Reveal answer

    It lets the system self-correct and stay reliable.

Take it home

Sketch a block diagram of your school bell system and mark where feedback is missing.

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