Why is insulated wire used in making motors

The photo of a drone motor shown above gives us perspective of how much copper goes into the motor, and why material weight is important to increase the efficiency of the motor. If we were able to easily decrease the weight of all that copper on the motor and maintain its power output, this would dramatically decrease the amount of power required to fly the drone. Copper is a great choice for motor windings because of its high conductivity and relatively low cost, but it is also a highly dense and heavy material; this is even more of a problem for motors used in electric vehicles or aircraft, which need to be lightweight.

Copper will work just fine for most motor applications, but when considering weight, strength, and stability in high temperature or other demanding environments, we should consider some other potentially better materials. If we were considering weight alone, Aluminum wire would be a great choice for magnet wire construction.

Aluminum is a commercially available magnet wire option, but because it is less conductive than copper, larger wire diameters and correspondingly larger motors would be necessary to create the same power outputs. Furthermore, Aluminum is more prone to flex fatigue and likely to break more easily after repeated movements. Another downside to aluminum is the increased potential for corrosion and the difficulty of keeping the contacts clean, causing a higher localized resistance and potential for connection point thermal failure.

Improvements could be gained by using a combination of aluminum with other metals to increase the conductivity, maintaining the same physical motor size and the same power output as a motor with copper windings while still decreasing the weight. Wires made from gold and silver offer a low resistance and are also more corrosion resistant than aluminum or copper; in fact, silver conducts electricity lightly better than copper itself. However, both gold and silver are substantially more expensive than copper.

The increased cost and low availability of these materials would make it difficult for these materials to become mainstream magnet wires for electric vehicles and aircraft. Carbon nanotube fibers and yarns have gained the attention of the electric motor and power generation industries due to the incredible combination of properties offered by CNT materials. Carbon nanotube fibers and yarns offer a highly flexible, strong, and lightweight option for motor winding constructions.

Carbon nanotubes also offer higher conductivity than copper at the molecular level, although it has not yet been demonstrated that CNT yarns can achieve this level of conductivity on the scale of macroscopic fibers. There may be an advantage to be gained by using CNT fibers in motors that operate at higher frequencies, because copper's electrical performance is reduced at higher frequency operation compared to that of CNT fibers.

Flexibility of CNT fibers is vastly superior to copper, being more comparable to that of a textile thread with the ability to survive millions of flex cycles. When the coil turns to face the magnet, the attraction is eliminated because, as you will see, half of the insulation on one side of one of the wire leads will be stripped; thus, current is not allowed to flow, and the coil does not act like a magnet.

However, the coil continues to rotate because of the momentum it gained before when it was magnetized. When the coil finishes one full rotation, the cycle starts over again because the non-insulated part rotates, current flows, and the coild becomes magnetized and attractive to the stationary magnet.

Wrap it 7 times around the toilet paper tube. Cut the wire, leaving another 3 inch tail on the opposite side of the original tail. Unlike bar magnets, which are permanent magnets, the magnetism of electromagnets can be turned on and off just by closing or opening the switch. Relays are electrically operated switches. They use an electromagnet, often to control a high-power circuit using a low-power signal or where multiple circuits need to be controlled by one circuit.