Monthly Archives: November 2022

Technology

The Basics of Electric Generators

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What are Electric Generators?

Hand starts a portable electric generator in front of a summer house in summer
Photo: iStock

Electric generators are the opposite of electric motors, but they work on the same concept. Whereby an electric motor uses an electric current to create a magnetic field, a generator uses a  magnetic field to induce an electric current. If you read our article on electric motors, then this should sound very familiar. The process is only reversed.

The current that is produced flows through a conductor which is usually a wire, but it can also be a metal plate. The output of the current is then used to power anything from a small device (e.g. a lamp or computer) to an entire town or city.

What They are Used For

Generators are used to create electricity which then powers homes and businesses. They can be powered by either an electromagnet or a permanent magnet. The type of generator you use will determine how much electricity you can generate.

They are often used to provide backup power in case of a power outage, and they are also used in many portable applications such as camping and RVing. Just about all emergency facilities have backup power, such as hospitals. 

In some cases, generators can also be used to supplement the main power source, providing additional power during high-demand periods.

The most common power sources are fuels such as coal, natural gas, or oil.

How Does an Electric Generator Create Energy?

When the generator is turned on, its moving parts create a magnetic field, producing an electric current. (Remember with electric motors, an electric current is produced that provides a magnetic field. This is the opposite of what generators do.) The current flows through wires to an external circuit, where it can be used to power electric devices. In this way, an electric generator converts mechanical energy into electrical energy.  

What are the different types of electric generators available on the market today?

The most common type uses a combustion engine to generate electricity. These engines can be powered by gasoline, diesel, natural gas, or propane.

Another type is the steam turbine, which uses steam to power a turbine that generates electricity. Steam turbines can be powered by coal, nuclear reactors, or solar thermal power plants.

The third type of generator is the hydroelectric generator, which uses water to power a turbine that generates electricity. Hydroelectric generators can be powered by waterfalls, dams, or river currents. The Niagara Project is a perfect example of the delivery of electricity via hydroelectric generators.

Illustration of a wind turbine
Wind turbines spin which produces a magnetic field which then produces electricity. Photo by Gonz DDL on Unsplash

The fourth type of generator is the wind turbine, which uses wind to power a turbine that generates electricity, but there must be enough wind for the proper amount of electricity to be produced.

Wind turbines can be used in both onshore and offshore locations.

 

How Can You Choose the Right Electric Generator for Your Needs and Budget?

With so many different brands, models, and features to choose from, it’s hard to know where to start. However, by considering a few factors, you can narrow down your options and find the perfect generator for your needs and budget.

First, decide what type of generator you need. For example, if you only need power for occasional use, such as during a power outage, a portable generator may be sufficient.

However, if you need a constant supply of electricity, such as for a construction site or an RV, a stationary generator would be a better choice.

Next, consider how much power you will need. For most applications, a small generator that produces around 2,000 watts will suffice.

However, if you need to run large appliances or multiple devices at once, you’ll need a more powerful model. Finally, compare prices to find the best value for your money. Be sure to factor in the cost of fuel and maintenance when making your decision. By considering these factors, you can find the perfect electric generator for your needs and budget.

Important Safety Tips

 First, always read the manufacturer’s instructions carefully before operating the generator. This will help you to understand how the generator works and what safety measures need to be taken.

Next, make sure that the generator is properly grounded before use. This will help to prevent electrical shock. Finally, never operate the generator near flammable materials or in enclosed spaces, as this can create a fire hazard.

By following these simple safety tips, you can help to ensure that your experience with an electric generator is safe and enjoyable.

Technology

How an Electric Motor Works

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Overview

3D cut out illustration of an electric motor
Cross section of an electric motor. Photo: iStock

When an electric current runs through a wire, a magnetic field is produced and when there is a magnetic field, metallic elements become attracted to it. This is the concept behind the workings of an electric motor.

If we can maintain these elements to move towards the magnetic field and away from it at an ongoing, continuous rate, we can have a device that is constantly spinning.

If we attach something to the part of the device that is constantly spinning, such as a glass plate in the microwave, we have harnessed the power of converting electrical energy into mechanical energy, or more specifically, we have created an electric motor.

What Devices Use Electric Motors?

When you use an electric razor, toothbrush, fan, or vacuum cleaner, you are using an electric motor. Let’s through the inner workings of your car also. That’s probably no surprise, but how about this: washing machines, refrigerators, microwaves, your computer, and even your smartphone!

Confused? Don’t be. Something is needed to operate the refrigerator’s compressor. If there is a mechanical hard drive in your computer, then there is a small motor that turns the disk. And microwaves? Well, something must be spinning that glass plate around, right?

And your electric cars (if you have one). They have motors, which are used to spin the tires as you drive, among other things.

The bottom line is you probably go about your day using some device that uses an electric motor. So now that we know how our lifestyles are affected by these devices, let’s delve into how these motors work.

The Working of an Electric Motor 

First, let us focus on the magnetic field that causes the components within the motor to constantly spin.

How is the magnetic field created? Our article on magnetic fields explains this, but in a nutshell, if we connect a wire to a battery, the electrons of each of the atoms will move toward the positive pole of the battery. If we wrap the wire around a metal rod, the magnetic field intensifies.

Inside of an electric motor.
Inside of an electric motor. Photo: iStock

The Initial Stage

The motor is designed so that the magnetic poles of a rod, called a rotor are always facing the same polarity of a stationary magnet, called a stator, causing the rotor to spin around.

For example, when electricity is turned on, the polarity of one side of the rotor, let’s say the north side is initially facing the north side of the stator, so there will be that repelling effect, causing the rotor to spin in the other direction.

The Next Stage

Well, that initial stage works just as it should because like poles repel each other, but that’s it. Then it stops, so for the rotor to keep spinning, there has to be a mechanism that will cause the poles to reverse continuously.

That is the job of the commutator. This entity keeps reversing the path of the electrons so that the poles are always repelling one another and consequently, keeps the rotor spinning.

Key Parts of an Electric Motor

Let’s review the parts of the motor:

    • Stator – The stationary part of the motor that creates the magnetic field that causes the rotor to spin. The stator is found in between two pieces of copper that conduct electricity.
    • Rotor – The rotating part of the motor is placed within the magnetic field.
    • Shaft – The motor shaft connects the rotor to the stator and is used to power the equipment or machinery.
    • Commutator – The device that reverses the polarity of the rotor. Like reversing a battery at every spin so that the electrons change course.
    • Fan – The fan is used to create airflow and increase the efficiency of a motor.

Final Words

Electric motors are all around us. They are a safe, efficient, and reliable way to power machinery and equipment. They are available in a range of sizes, voltages, and designs and can be powered by a wide range of energy sources, including fossil fuels and renewable energy sources like solar or wind. 

 

Technology

Electromagnetism: From the Basics to Everyday Applications

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Depiction of a wire wrapped around a nail with the wire connected to a battery creating a circuit and consequently creating an electromagnetic.
Depiction of a wire wrapped around a nail and connected to a battery, creating a complete circuit, resulting in the creation of an electromagnetic. When electrons start to run through the wire (from one end of the battery to the other), a magnetic field is produced and the nail is magnetized, consequently, the paper clips are attracted to the nail. If the power shuts off, the paper clips will no longer have that attraction. Photo: iStock.

Let’s Start with a Piece of Metal

Let’s use iron for example. Touch it with another piece of iron and what happens? Nothing! Now take a bare wire, copper preferred. Wrap the copper wire around one of the pieces of iron and what happens? Still nothing!

Now grab both ends of the copper wire and connect it to a battery. What happens? Still nothing – at least nothing noticeable that the naked eye can see!

What is happening when the wires connect to the battery (called a circuit) is that the electrons were random before the circuit was completed and they straightened out, like a row of marching soldiers after the circuit is complete.

These marching electrons will point and move towards the pole ( polarity) of the battery it is connected to. Now let’s get a little more technically correct and call these marching electrons an electric current, and as these electrons (current) are moving through the wire, a magnetic field is produced. 

When There is Electric Current, There is a Magnetic Field

Illustration of wires wrapped around metal and connected and disconnected to a battery
Left: Iron bar with wire wrapped around it (coil) and iron filings nearby laying stationary because the wires are not a complete circuit (connected to the battery).  Right: Same configuration but with the circuit complete and iron fillings are then attracted to it. Photo: iStock

But Just What is This Magnetic Field?

If we pick up the other piece of iron (which does not have the copper wire around it) and place it near the iron piece that has the wire wrapped (and thus the electric current), that isolated piece of iron suddenly moves toward the electrified one.

The reason why the iron pieces attract each other is that the iron piece with the copper wire wrapped around it (called a coil) becomes magnetic. And so, we have just created an electromagnet! 

For the video below, you might want to put your thinking caps on as it explains pretty well how electromagnetic forces are derived (hint: when electrons move through a wire). We suggest those that who are in school and/or have an absorption for learning continue to this video.

For those that would like to bypass such items as Maxwell’s equations and just want a cheat sheet of what is the criteria for an electromagnetic field, see our summary below.

How Electromagnets are Made

An electromagnet can be made out of any type of metal, but iron and nickel are the ones most often used. Nickel magnets are stronger than iron magnets, but iron is cheaper. 

Iron is found in most scrap yards, or you can buy it from a hardware store. The first step in making an electromagnet is to create a wire that is wrapped with a coil of metal several times. This is known as an electromagnet coil. The coil has to be wrapped around a core, which is made out of a non-magnetic material. 

The Magnetic Field

A picture of a magnet
A permanent magnet has the same properties as an electromagnet but without the current. Image by Francesco Bovolin from Pixabay

The electromagnetic field is the region of energy surrounding a magnet. The magnetic field is perpendicular to the path where the electrons flow.

Why are Electromagnets Important?

Electromagnets are important because they can be used to power items and devices that are used by us every day. Motors and generators are just two examples. They are also used in toys, as a way of moving things around in a car or even to move things in a factory. 

They are also useful because they’re easily controllable. If you want to turn the electromagnet off, you simply turn off the electric current running through it. If you want to turn it back on, you can simply turn it back on again.

Types of Magnets

There are two types: temporary and permanent. Temporary magnets are only magnetic while electricity is running through them. Permanent magnets remain magnetic no matter what happens. This is because these magnets are not electrified. An example is the ones stuck to your fridge or another metal surface.

Conclusion

Magnetism is created when electrons are in movement. In a practical sense, this means that if you connect a wire to a battery (power source), electrons will move from the negative pole to the positive pole of the battery.

When this happens, a force is created in addition to the electrical force, which is the magnetic force. This magnetic force ‘pushes’ perpendicular to electrical force (current), so any metal that has magnetic properties will be attracted to this force and move towards it accordingly.

The magnetic force can be strengthened by any of the following criteria.

    • Take the straight wire and curl it around the medium, usually an iron bar. The result is called a coil.
    • Wiring the coil more will cause the magnetic field to strengthen.
    • Increasing the current; that is, increasing the speed at which the electrons travel through the coiled wire will also strengthen the magnetic field.

The practical applications of electromagnets are the ability to cause an entity to move because of this force, such as what happens inside a motor.