Springfield Fet College

DHET REG: 2009 FE07/100

Class of Electrical Engineering at Springfield Rustenburg Campus
By:Mike B     Date Published:22-Jun-2017     Views:32283

Students practicing light current wiring

Students were taught  to explore how current electricity travels in pathways called circuits.

Students taught to create a working circuit using a light bulb, battery, two types of switches, and wire.

• I can define the terms “circuit” and “current electricity” and tell you where we used them in everyday life.

• I can describe the difference between closed, open, and short circuits as applied to real life situations.

• I can show you how a switch works and why switches are important.

• I can explain electrical insulator and conductor and give several examples of each. Background Like static electricity, current electricity involves the movement of electrons.

The difference is that in current electricity electrons move from atom to atom along a pathway called a circuit. To create a circuit you need wire, an electrical source such as a battery, and a load (the item you want to work such as a light bulb or motor).

The electricity must be able to move from one end of the electrical source (the battery, turbine generator or photovoltaic panel) to the load and back to the electrical source to create a complete circuit. Electricity taught to only do work (example: light the bulb or run a motor) when it is complete or closed.

 In a closed-circuit electron are able to travel the entire pathway (loop) without hindrance via materials that conduct electricity. In an open circuit, there is a disruption in the pathway caused by a break in the loop because of the absence of material that can easily conduct electricity.

Thus, electrons are unable to move through these locations and make a complete circuit. You can think of an open circuit as a toy train track assembled to form a circle with a piece of track missing.

As the train, (think of it as electrons), moves along the track it derails at the missing track piece and cannot complete the circle (circuit). A short circuit is when there is a complete circuit or loop, but the flow of electrons takes a “short-cut” bypassing the load.

Short circuits happen when the wiring of a circuit is faulty and does not form a pathway that must pass through the load as seen in class lessons

 Current Electricity – Circuits and Switches.

If the circuit is shorted, the load will not work. For example, if the load is a bulb it will not light because it is not receiving the electricity (electrons). The wires we will be using are made of copper or aluminum, which are conductors (they readily transmit electricity). The wire is coated with plastic; an insulator (does not allow any significant flow of electrical current).

Everyday materials are divided into two groups: conductors and insulators. Most metals like copper, aluminum, iron, zinc and steel are conductors. Water is also a fairly good conductor, especially if it contains minerals and/or electrolytes. Insulating materials include rubber, plastic, glass, and wood.

The electricity will flow from the electrical source (battery) through the wires to the load (light bulb).

In everyday use of electricity, humans use switches to turn on and off the flow of electricity to electrical devices. The switch is an important part of the circuit even though it is a simple concept.

The switch in a circuit merely allows one to open or close the circuit, controlling the flow of electrons along the pathway. If one turns the switch on, the switch closes the circuit allowing electricity to flow.

Turn the switch off and it opens the circuit – electrons can’t cross the tiny space created inside the switch.

The three kinds of switches provided in the following activity taught to allow students to explore the way “on” switches allow a closed circuit to be created and “off” switches allow an open circuit to be created. 

By: Mike B
Campus Director

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