Systems Approach to Designing
Below is a collection of revision 'flashcards' that cover the exact key terms found in the UK GCSE curriculum Design and Technology syllabus. Take your time to learn and remember the terms on each flash card. Real world examples are also provided for use in written exam answers!
Input & Output Devices
Glossary of Key Terms
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Light Dependent Resistors (LDR)
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Thermistors
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Switches
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Lamps & LEDs
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Buzzers & Amplifiers
Light dependent resistors (LDRs), also known as photoresistors, are passive electronic components whose electrical resistance changes in response to variations in light intensity. LDRs are commonly used in light sensing applications, such as automatic streetlights, camera exposure control, solar panels, and optical switching circuits, where they serve as light sensors or detectors. They offer a simple and cost-effective means of detecting and measuring light levels in electronic systems, allowing devices to adapt their behavior based on ambient light conditions.
Thermistors are temperature-sensitive resistors that create a significant change in electrical resistance in response to changes in temperature. They are made of semiconductor materials, such as metal oxides or polymers. Thermistors can be classified into two main types: negative temperature coefficient (NTC) thermistors and positive temperature coefficient (PTC) thermistors. NTC thermistors show a decrease in resistance with increasing temperature, while PTC thermistors show an increase in resistance with rising temperature. Thermistors are widely used in temperature sensing and control applications, such as thermostats, temperature monitoring systems, and temperature measurement devices. They offer high sensitivity, accuracy, and stability over a wide temperature range, making them essential components in various electronic and electrical systems.
Switches in an electronic circuit are devices that control the flow of electric current by either allowing or interrupting the flow of electricity. They serve as on/off mechanisms, allowing users to manually control the operation of electrical devices or circuits. Switches come in various types, including toggle switches, push-button switches, rocker switches, rotary switches, and slide switches, each with its own method of actuation and functionality. When the switch is in the "on" position, it completes the circuit, allowing current to flow through the connected components. Conversely, when the switch is in the "off" position, it breaks the circuit, preventing the flow of current. Switches play a crucial role in electronic devices and systems, enabling users to turn equipment on or off, select different operating modes, and control various functions.
Lamps and LEDs (Light Emitting Diodes) are lighting components employed in electronics to produce light. Lamps generate light by heating a filament inside a glass bulb until it glows, typically containing inert gases to prevent oxidation. Commonly used in indicator lights, displays, and general lighting, lamps are traditional lighting devices. LEDs, on the other hand, utilize semiconductor materials to emit light when an electric current passes through them, operating via electroluminescence. Highly efficient, durable, and versatile, LEDs have a long lifespan, low power consumption, and find applications in indicator lights, display backlighting, signage, automotive lighting, and general illumination. LEDs have become the standard for today's modern lighting.
Buzzers and amplifiers are integral components in electronics for audio-related functions. Buzzers, consisting of a vibrating membrane or diaphragm driven by an electromagnetic coil, generate sound waves when an electric current passes through, commonly used for audible alarms, notifications, and alerts in electronic devices. Amplifiers, on the other hand, are electronic circuits designed to increase the strength of electrical signals, converting weak input signals into stronger output signals. With various types and configurations like operational amplifiers (op-amps), transistor amplifiers, and integrated circuit (IC) amplifiers, amplifiers play a crucial role in audio systems, communications equipment, and instrumentation, where signal amplification is necessary to drive speakers, headphones, antennas, or other output devices.
Microcontrollers
Glossary of Key Terms
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Processors & CPUs
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PIC chips
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Counters & Timers
A processor, also known as a central processing unit (CPU), is the primary component in an electronic system responsible for executing instructions and performing calculations. It is often referred to as the "brain" of the system. Processors are integrated circuits that contain millions or even billions of transistors arranged in complex arrangements. They interpret and execute instructions stored in memory, perform arithmetic and logical operations, control data movement within the system, and manage input and output operations. Processors come in various types, including microprocessors, microcontrollers, and digital signal processors (DSPs), each designed for specific tasks and applications. They are found in a wide range of electronic devices, including computers, smartphones, tablets, appliances, automotive systems, and industrial equipment, where they play a crucial role in controlling and processing data to perform desired functions.
A PIC chip, short for Peripheral Interface Controller chip, is a type of microcontroller manufactured by Microchip Technology. It is a small, single-chip computer that contains a processor core, memory, input/output peripherals, and various other integrated circuits on a single integrated circuit. PIC chips are widely used in embedded systems and electronic devices for controlling and monitoring functions. They are programmed to perform specific tasks and can interface with sensors, actuators, displays, and other electronic components. PIC chips come in various models with different features and capabilities, offering flexibility and scalability for a wide range of applications. They are commonly used in automotive systems, consumer electronics, industrial automation, and other embedded applications due to their reliability, cost-effectiveness, and ease of use.
Counters and timers are vital components within electronic systems, serving distinct functions to measure time intervals, count events, and regulate timing operations. Counters, typically digital circuits or devices, increment or decrement a count based on external signals or clock pulses, enabling them to track the number of input events or pulses received and output corresponding count values. Meanwhile, timers, electronic circuits or devices, generate precise time delays or intervals, allowing for control over the duration of specific operations or events. Both counters and timers play critical roles in various applications, including frequency measurement, event counting, pulse generation, timing sequences, and real-time clock functions in embedded systems, automation, and electronic instrumentation.