Electricity is a fundamental form of energy that powers our world.
Electrical devices require electricity to operate.
From household appliances such as refrigerators, televisions, and vacuum cleaners, to hand-held power tools, cars for power windows, portable power tools, and electric machines, the omnipresent role of electricity is inescapable.
Do you know how electricity is created?
And how do batteries operate a motor?
The answer lies in the relationship between electricity and magnetic fields, including permanent magnets such as the neodymium disc magnet and ceramic magnets.
Electricity is created using a magnetic field.
It is generated through the interaction between a magnetic field and the flow of electrons, known as electric current.
A simple homemade motor can be constructed using readily available materials such as a neodymium disc magnet, copper wire, and an alkaline battery.
It is crucial to emphasize the importance of adult supervision during such experiments, as magnets can pose a hazard if swallowed, and there is a risk of short circuits leading to excessive heat when handling battery terminals.
Also, insulated wire is recommended to ensure safety during the construction process.
And watch this video too!
If you like playing with magnets, you will love this building a simple motor experiment.
Warning: It is crucial to emphasize the importance of adult supervision during such experiments, as magnets can pose a hazard if swallowed. Please keep them away from children who still put everything into their mouths.
There is also a risk of short circuits leading to excessive heat when handling battery terminals. Insulated wire is recommended to ensure safety during the construction process.
- neodymium disc magnet
- (thick) copper wire or this thinner version that we used (which is more challenging but still doable)
- alkaline battery such as AA or AAA
- wire cutter
- a plastic ring to support the magnet (optional)
- adult supervision
- Cut a piece of copper wire that is roughly 6-8 inches long.
- Bend the wire in the middle to create a contact point to stand on top of the battery.
- While the middle of the wire stands on top of the battery, bend both sides of the wire downwards.
- You can make any shape you want as long as the center can balance on the battery when it spins and the wire frame can touch the magnet that will be placed underneath the battery.
- (Optional) Place the magnet on top of the plastic ring. I use it because my wire frame is quite long and it will touch the table without the ring.
- Carefully put the battery in the center of the disc magnet. Since neodymium magnets are very strong, be careful not to pinch your fingers when doing this. If you need to pull the battery away from the magnet, slide it off the disc. Don’t pull the battery directly from above or you may risk breaking the magnet (or making it very hard to do for yourself).
- Slowly place the wire frame onto the battery and watch it spin.
Warning: Let go of the wire once it makes contact with the battery terminal. Holding a stationary wire to the battery terminals will cause a short circuit which can generate a lot of heat and burn your hand.
Making a wire frame that can balance and spin without falling can require some trial and error.
But once you get the basics, you can try making frames in other shapes.
One especially artsy version of this experiment is this wire dancer.
You just built a motor. Amazing, isn’t it?
What you’ve built is called a homopolar motor, which uses direct current from the battery to power rotational movement.
It is called a homopolar motor because, unlike conventional DC motors, the polarity of the magnetic field from the magnet does not change.
When electricity moves through a magnetic field, a force, called Lorentz Force, is generated.
In our experiment, the copper wire conducts electricity from one end of the battery through the magnet to the other end.
As the electric current moves through the magnetic field coming from the neodymium magnet, Lorentz Force is generated which causes the wire to spin.
What is Direct Current Electric Motor?
Electric motors vary widely in type and application, from miniature to induction motors, series-wound DC motors to universal motors, synchronous motors to brushless motors, and can-based electric motors to e-waste-based DIY motors.
One specific type of motor is the direct current (DC) motor, which uses the principles of electromagnetism to change electrical energy into motion.
A DC motor typically has two main parts: a rotor and a stator.
The stator holds stationary magnets and creates a magnetic field, while the rotor has coil wires that carry electricity.
The rotor spins within the non-moving stator and can be seen in many electric machines.
The motor armature serves as the essential component within the rotor, comprising a network of interconnected wires that facilitate the fascinating exchange between mechanical and electrical energy.
The simplest form of a DC motor is the homopolar motor.
It uses direct current from a battery to power rotational movement.
The homopolar motor was first built by Michael Faraday, an English scientist who significantly contributed to the study of electromagnetism and electrochemistry.
His experiments formed the foundation for future motor projects, including the homopolar motor.
A homopolar motor uses direct current electricity. It is a type of electrical current where the flow of electrons is constant and in one direction.
The power source for the motor is typically a battery, such as a 6V, a cell, or a rechargeable battery. The battery terminals, the positive and negative ends, are crucial for the motor’s functioning.
In a homopolar motor, a piece of copper wire serves as a conductor and connects the battery terminals.
Copper wire is an excellent conductor for it allows electrons to flow with minimal resistance.
The wire coil is shaped, allowing it to stand on the battery and conduct electricity to the magnet placed.
This setup forms a simple and effective closed circuit, a complete path that allows the flow of electric current, contrasting with more complicated motor speed controllers.
Caution: To keep the coils of wire stable and insulated in a homopolar motor, electrical tape is used.
Wrapping the tape around the coil and battery terminals protects the wire from damage or unintended contact with other components.
Do neodymium magnets conduct electricity?
Our homemade dc motor’s working is mainly based on the neodymium disc magnet.
Neodymium magnets are created from an alloy of neodymium, iron, and boron.
Neodymium magnet has great electromagnetic fields and exceptional resistance to demagnetization compared to ceramic or temporary magnets like iron, making them ideal for use in standard motors.
The electromagnetic fields produced by neodymium magnets cause the copper wire to spin when electricity flows through it.
This is known as the Lorentz Force, which occurs when a force acts at a right angle to both the electric current and the magnetic field, leading to the wire’s spinning motion.
This principle determines the direction of rotation in our homopolar motor.
The homopolar motor’s mechanism involves several factors, including the electric force resulting from the flow of electric current, the magnetic force from the neodymium magnet’s magnetic field, and the Lorentz Force arising from the interaction of these forces.
Together, they create a torque or turning force that causes the wire coil to spin around the battery.
The starting power of a motor depends on the electromagnetic field and the electric current. It shows how quickly it can overcome resistance and start rotating.
Building a simple DC electric motor is entertaining and helps demonstrate the principles of electromagnetism.
This activity offers a fun and hands-on way to learn about the workings of different types of motors, the role of motor components, the flow of electric current, the interaction of various forces, and how electrical energy converts to mechanical energy.
Remember that the world of electromagnetism is captivating and full of possibilities. So, continue exploring this fascinating field with enjoyable electric motor projects.