Back to: BASIC TECHNOLOGY JSS3
Welcome to class!
In today’s class, we will be talking about basic electronics components. Enjoy the class!
Basic Electronics Components
Introduction
When current produced is used in communication, they are made to carry information such as sound, pictures, numbers and voices. This is made possible by the use of electronic devices which incorporates electronics components like transistors, diodes, resistors, capacitors, inductors, triodes, etc. in their circuits.
We will be looking at these electronic devices one after the other.
1. Diodes:
This is an example of a vacuum tube. It contains two metal electrodes i.e. anode and cathode placed directly opposite one another inside a vacuum of either glass or metal.
NB: The first electrode is called the cathode.
The diode works on the principle that; like charges repel each other while unlike charges attract each other.
When the cathode is heated, it emits electrons which are negatively charged and provided the anode is positively charged, electrons are attracted to the anode creating an electric field between the anode and the cathode.
In the diode electrons, current flow from the cathode to anode, and can never be from anode to cathode which is a unidirectional flow of current. This makes diodes useful in making electronic switches and as rectifiers that is, for changing alternating current (AC) to direct current (DC).
2. Triodes:
The triode is a vacuum tube which is made of three elements namely anode, cathode and control grid. The only difference between a diode and a triode is the presence of a third electrode called the control grid, placed between the anode and the cathode. The control grid controls the flow of electrons from the cathode to anode. The triode is used for amplifying current.
3. Gas discharge tube:
In a gas discharge tube, a small quantity of gas such as neon, argon, helium, and nitrogen is introduced to the vacuum. The gas helps to decrease the temperature thereby improving ionization in the tube.
The difference between a discharge lamp and a vacuum tube is the gas. Examples of gas discharge include a neon lamp, fluorescent lamp and halogen lamp.
4. Transistors:
A transistor is a small solid electronic device used in computers, radios, televisions etc. for controlling an electric current as it passes along a circuit.
Transistor are smaller than valves, they have a longer lifespan than valves. They do not require any heating as a source of energy since they need no filaments.
NOTE: Transistors are made of semiconductor materials such as germanium and silicon.
Technology of appliances
Common appliances are devices, which convert energy from one form to another for their operations. A common example is a refrigerator.
Note: This is an appliance, which extracts heat from the space to be refrigerated and passes it out into the surrounding.
Essential components of a refrigerator
- Refrigerator: This is fluid which changes its state very easily due to heat transfer. This changes from liquid to gas and gas to liquid. E.g. Sulphur dioxide
- Evaporator: This is the extraction of heat from food items to be refrigerated which takes place in the evaporator.
- Compressor: This helps to circulate the refrigerant in the system by pumping action.
- Condenser: The extracted heat in the evaporator is disposed of in the condenser. This shows that the condensation of refrigerant takes place in the condenser.
Properties of a refrigerant
- A refrigerant should not be explosive
- It should be toxic
- A refrigerant should be easy to detect for leakage
- It should have a low boiling point
- It should not be flammable
In our next class, we will be talking about MACHINE MOTION. We hope you enjoyed the class.
Should you have any further question, feel free to ask in the comment section below and trust us to respond as soon as possible.
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Learning so interesting it is very good for students studying Electronic Engineering.
I am pleased with the lesson
The course is absolutely interested for basic electronics student it’s comprehensive and summerised