Basic Electronics I – JSS3 Basic Technology Lesson Note (Third Term)

Basic electronics i

Basic electronic components include:

1. Resistor: Restricts the flow of electric current.
2. Capacitor: Stores and releases electrical energy.
3. Inductor: Stores energy in a magnetic field when current flows through it.
4. Diode: Allows current to flow in one direction only.
5. Transistor: Amplifies or switches electronic signals.
6. Integrated Circuit (IC): Miniaturized arrangement of transistors, resistors, and capacitors on a single chip.
7. Voltage Regulator: Maintains a stable voltage output.
8. Battery: Stores electrical energy.
9. LED (Light Emitting Diode): Emits light when current flows through it.
10. Switch: controls the flow of electricity by opening or closing a circuit.

Basic Emission Theory

Electron emission refers to the process in which electrons are expelled or released from a material or surface. There are several mechanisms through which electron emission can occur:

1. Thermionic Emission: Here electrons are emitted from a material when it is heated. The heat provides enough energy to overcome the material’s work function, allowing electrons to escape.
2. Field Emission: In field emission, electrons are emitted by a material in the presence of a strong electric field. This mechanism is common in nanoscale structures, where the electric field is sufficient to overcome the material’s work function.
3. Photoelectric Emission: Electrons are emitted from a material when it is exposed to light or electromagnetic radiation. The incident photons transfer energy to electrons, enabling them to overcome the work function and be emitted.
4. Secondary Emission: In secondary emission, the electrons are released from a material when it is bombarded by high-energy electrons, ions, or photons. This secondary emission is often utilized in devices like photomultiplier tubes.
5. Cold Emission (Field Electron Emission): Electrons are emitted at room temperature or lower temperatures in the presence of a strong electric field. This phenomenon is observed in specific materials with high field-enhancement factors.

Types of Basic Electronic Devices

Basic electronic devices are devices that emit and control the movement of electrons in a desirable manner used in the generation of electronic appliances. The following are the types of basic electronic devices:

1. Semi-Conductors: Semi-conductors are those substances whose electrical conductivity lies between the good conductors (metallic substances) and good insulators (non-metallic substances) E.g. Silicon, Germanium.
2. Resistor: A Resistor is a device used to control the flow of electric current in an electric circuit or which opposes the flow of an electric circuit. The ability of a Resistor to control the flow of electric current is called RESISTANCE. The resistor is measured in Ohms by a device called Ohm meter.
3. Capacitors: A capacitor is a piece of an apparatus designed to store electrical energies in the form of electric charges. An example of a capacitor is a Condenser or starter in a fluorescent lamp. The capacitors are available in motor vehicles air conditioners etc.
4. Capacitance: This is a phenomenon that exists when certain parts of an electric circuit can store electric charges.

Capacitance (C) = Charge on either plate (Q)/P.d across the plates (V).

The S.I unit of a capacitance is farad (F)

1. Transistors: Transistors are semiconductor materials that are capable of providing amplification in electronic equipment. They are smaller than vacuum tubes; the vacuum tubes control the flow of electrons in the airless space while the transistors control the flow of electrons in the semiconductor materials.

The transistor has three electrodes in the terminals

1. The Emitter (E)
2. The Base (B)
3. The Collector (C)

The types of transistors are:

1. NPN Transistor: Consists of three layers: the N-type semiconductor (negative), the P-type semiconductor (positive), and another N-type semiconductor.When a small current flows into the base (P-type), it controls a larger current flowing between the collector (N-type) and the emitter (N-type), allowing for signal amplification.
2. PNP Transistor: Similar to the NPN transistor but with the layers reversed: P-type semiconductor, N-type semiconductor, and another P-type semiconductor. The flow of current and signal amplification occurs in the opposite direction compared to NPN transistors.

EVALUATION: 1. What is electron emission?

1. Identify and explain 4 types of electron emission
2. Identify 10 basic electronic components and state their uses.

Basic electronics II

Components of Electronic Devices

Electronic devices consist of various components that work together to perform specific functions. Here are some key components and a brief discussion of their roles:

1. Microprocessor/Microcontroller: A microprocessor and a microcontroller are both integrated circuits that serve as the central processing unit (CPU) of a computer or an embedded system. While they share some similarities, they are designed for different applications.
2. Memory (RAM and ROM): RAM (Random Access Memory) provides temporary storage for data during operation, while ROM (Read-Only Memory) stores permanent data, including firmware and system instructions.
3. Transistor: A transistor is a semiconductor device that can amplify or switch electronic signals. It is a fundamental building block in modern electronics and serves various purposes in electronic circuits. Transistors are essential for controlling the flow of electrical current and manipulating signals in electronic devices.
4. Resistor: A resistor is an electronic component that restricts or limits the flow of electric current in a circuit. It is a passive two-terminal device with the primary function of controlling the amount of current that can pass through it.
5. Capacitor: A capacitor is an electronic component that stores electrical energy in an electric field. It consists of two conductive plates separated by an insulating material known as a dielectric. The capacitance of a capacitor, measured in farads (F), represents its ability to store charge.
6. Diode: A diode is a semiconductor device that allows current to flow in one direction only. It typically consists of a semiconductor material, often with two layers – one doped to have excess electrons (N-type) and the other doped to have a deficit of electrons (P-type). The junction between these layers forms a diode.
7. Integrated Circuit (IC): An integrated circuit (IC), also known as a microchip or chip, is a compact arrangement of transistors, resistors, capacitors, and other electronic components on a single semiconductor substrate or chip. The integration of these components onto a single chip allows for the creation of complex electronic circuits in a small and efficient form.
8. Inductor: An inductor is an electronic component that stores electrical energy in a magnetic field when an electric current flows through it. It typically consists of a coil of wire wound around a core, often made of ferromagnetic material.
9. Sensor: They convert physical or environmental data into electrical signals, facilitating functions like temperature sensing, motion detection, etc.
10. LED (Light Emitting Diode): A semiconductor device that emits light when current flows through it, used for display indicators and lighting.
11. Microphone and Speaker: They convert sound waves into electrical signals (microphone) and vice versa (speaker) in audio devices.
12. Battery: A battery stores electrical energy for portable devices, providing a power source.
13. Switch: It controls the flow of electricity by opening or closing a circuit.
14. Connector and Cables: Facilitate the connection and communication between different components within a device.

EVALUATION: 1. Identify 10 components of electronic devices

1. Describe the uses of each component mentioned in 1 above.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively