Tag: Electromagnetism

Induction Cooking

Induction Cooking

Induction Cooking

05/08/19

“How can flameless cooking be done through magnetism?”

Preparing food is one of the most important elements of human life. Every culture has placed some form of emphasis on it, and cherishes it to the utmost. However, in the past in has relied on burning gas, coal, or wood to operate. Not only is this dangerous to the environment and human health but is also inefficient. But with the advance of new technology, cooking can be done in an entirely new way. Instead of having separate burners, the cookstove can be a flat magnetic plate. When activated, the magnets will induce eddy currents into the cookware, generating heat and cooking food. Not only is this much more energy efficient but also uses no flames! This Induction Cooking is a great way to decarbonize the world of cooking.

Image credit Wikipedia

Should California Only Important Electricity Through HVDC Lines During the Rainy Season?

Should California Only Important Electricity Through HVDC Lines During the Rainy Season?

Should California Only Important Electricity Through HVDC Lines During the Rainy Season?

03/28/19

“Should California only import high voltage electricity from other states at certain times of the year?”

California has ambitious plans with renewable energy. Not only is it the leading market in the United States, but plans to completely decarbonize its energy grid by 2045! However, this may require importing wind energy from Wyoming and Hydropower from the Pacific Northwest. The most efficient way to do this is to use HVDC lines with low levels of resistive losses. However, with the advent of climate change, California is experiencing much more and longer periods of drought. This creates fertile conditions for fires, which can be easily triggered in the case of a power line fault. Given that HVDC lines are at such high voltages, a single slip from one can cause intensive damage. As a result, it might be wise for California to only import electricity during the rainy season. Doing this will increase resilience protection and help stabilize the grid during the less sunny winter days. Since wind and hydro resources are also more plentiful when it rains, it would be a great way for other states to offset their surpluses during this time. This might be unnecessary if advanced fault detection and diagnostic technologies are used, but only studies will be able to say for sure!

Quantum Dots for Solar Panels

Quantum Dots for Solar Panels

Quantum Dots for Solar Panels

02/25/19

“Why are quantum dots for solar panels so useful?”

 

Quantum dots are bringing a revolution into the world of semiconductors. And since semiconductors are the backbones of solar panels, things will be greatly changed for them as well. The extra emissivity offered by quantum dots means that two and possibly three electrons can be generated for every photon received, vastly increasing its potential! Quantum dot solar panels can achieve as much as 65% efficiency, nearly double of the theoretical limit of normal panels. This is why Quantum Dots for Solar Panels are so exciting.

Image link https://upload.wikimedia.org

Synchronous Motors

Synchronous Motors

Synchronous Motors

01/01/19

“How can motors be synchronized with current?”

 

AC Motors can convert electrical energy supplied by current into mechanical energy. But are there motors where the frequency of the shaft’s rotation is equal to the frequency of the supply current? Well, it turns out these machines are known as Synchronous Motors and are used in cases where motor speed needs to be very precise.

 

Image credit http://3.bp.blogspot.com

Op-Amp Feedback

Op-Amp Feedback

Op-Amp Feedback

04/07/18

“How can we control voltage levels using an Op-Amp?”

 

Op-Amps are great for modifying voltage levels in a circuit. But sometimes things happen during the lifespan of an Op-Amp that can affect how it performs. So how can we design these components to self-regulate? Well, what if we were to connect part of the output circuit to the Op-Amp input. Therefore, the voltage levels would be the same as the input, and any change on one side would affect the other. This technique is known as Op-Amp Feedback and is one of the fundamental concepts of modern circuitry.

Electrostatic Precipitators

Electrostatic Precipitators

Electrostatic Precipitators

12/25/17

“How can we remove fine particles from a gas without contact?”

 

When a gas is being transported for use, it often has many fine particles (such as dust and smoke) attached, which can induce health issues. Traditional methods of removing these particles involve using physical barriers to filter out all particles. However, this has the effect of disrupting the flow of the gas. So how can we use our engineering mindset to solve this problem? Well, we know that from fundamental physics that there are two types of forces (contact and distance). And we also know that the latter can be caused by either gravitation, electrical, or nuclear interactions. And these fine particles in the gas are susceptible to become polarized and become at the whim of electromagnetic interaction. So what if we were to simply implement electromagnetic plates perpendicular to the flow of a gas, and suck up all of the fine particles while keeping the gas itself intact? Well, this is the fundamental idea behind Electrostatic Precipitators and are used in industries all around the world.

Magnetic domains, hysteresis, and hard/soft magnets

Magnetic domains, hysteresis, and hard/soft magnets

 

Magnetic domains, hysteresis, and hard/soft magnets

05/22/17

“How do magnetic fields come about and how can we apply this knowledge?”

 

The subatomic interactions in a magnetic object from material properties give rise to its macroscopic phenomena. Magnetic materials are composed of divisions known as magnetic domains that have a random magnetic field direction. When an external magnetic field is applied to a material, all of these domains will align with said field and produce a magnetic force. The magnitude of this magnetic force emanating from the object will be the result of the summation of the magnetic fields from all of the individual domains.

This theory can be applied using a hysteresis loop operates as follows. Take a piece of metal. Now run a coil around it. Generate an AC voltage. At t = 0, there will be magnetic activity in neither the metal nor the coil. When the voltage is increased, it will cause the domains to line up, eventually reaching a maximum value. Now pull the voltage in the other direction. When the voltage is equal to zero, the metal will have some residual magnetic field in it as a result of the shifting domains. If we pull the voltage into a negative state, then eventually it will reach another maximum (at the negative of the original boundary). If we reverse the direction of the current again to zero, then we will also have some residual magnetic field at zero. And if we increase the voltage in the positive direction, then we will reach the maximum again (Schuster, Doc).

 

Based upon their hysteresis profile, a material may be classified into either a hard magnet or a soft magnet. The former has a large profile, and are often used for energy intensive applications such as permanent magnets, while the latter has a smaller profile ideal for use in low energy loss application such as transformers.

Atulasimha, Jatulasimha. “Magnetism.” Magnetism for General Audience. Virginia Commonwealth University, 8 Nov. 2015. Web. 22 May 2017.

 

Callister, William, and David G. Rethwisch.Materials Science and Engineering: An Introduction. 9thed. , John Wiley & Sons, Inc., 2014.

 

Magnetic Hysteresis or I KNOW WHAT YOUR MAGNET DID LAST SUMMER | Doc Physics. Dir. Doc Schuster. Perf. Doc Schuster. Youtube. Doc Schuster, 25 Feb. 2014. Web. 22 May 2017.