Of the extensive list of components, the Capacitor is one of the most utilised.

It is an essential part of many circuits, and I would be surprised if I were to stumble upon one that does not contain a capacitor. 

The capacitor is very versatile and has many different applications which include Power Conditioning, Power factor correction, Signal coupling, Decoupling and much more.

Another common application of a capacitor is Energy storage.

But, does a capacitor store energy in the form of a magnetic field?

No, a capacitor does not store energy in the form of a magnetic field. Energy storage in a capacitor is in the form of an Electric Field which is contained between the two conducting plates within the housing of the capacitor.

How a capacitor stores energy in the form of an electric field

So, we now know that energy in a capacitor is not stored in the form of a magnetic field, but rather an electric one.

Let’s dive deeper into how a capacitor is constructed and how it stores its energy. 

Capacitors come in a variety of shapes, sizes, material used, etc. But the basic construction and operation from one capacitor to the next stays the same. 

It typically contains two parallel conducting plates which are separated by a dielectric.

When power is applied to the capacitor, an electric charge is generated between the two plates. This process causes one plate to be positive and the other negative. 

Fundamentals of how electric fields are formed

But, why does an electric field form?

To understand why, let’s take a closer look at the Electric Field. 

If we had the ability to view an electric field, you would see that it is a physical field that surrounds an electrically charged particle ( both positive and negative)

Just like a magnet creates a Magnetic Field that cannot be seen, an electrically charged particle produces an Electric Field that cannot be seen.  

Also, just like magnets, charges of the same polarity repel each other, while opposite charges attract each other. 

In the diagram you can see that electric fields radiate away from positive charges, and towards negative charges.

The electric field inside a capacitor

The simplest form of a capacitor is two metal plates separated by a dielectric as we saw earlier.

When a voltage is applied to a capacitor, an electron is added to one plate making it negatively charged.

This electron has an electric field which repels other electrons. It travels through the space between the plates and bumps the electrons off the other plate making it positively charged.

As the process increases, the amount of electrons added to the first plate increases thus increasing its negative charge, which in turn increases the induced positive charge on the second plate. 

Eventually, the amount of negative charge on the first plate is going to reach a maximum value which will prevent the battery from adding more electrons.

The capacitor is said to be fully charged at this point, and its electric field will be at its strongest. 

Since electric fields radiate away from positive charges and towards negative ones, an electric field will point across the gap between the two metal plates in straight lines. 

How much energy is stored within the electric field of a capacitor?

When a capacitor is connected to a power source (like a battery), it stores the received energy in the form of the electric field which we have just discussed. 

The amount of energy stored in a capacitor’s electric field comes down to a singular formula and a couple of variables. 

Without going into too much detail of its derivation, below is the formula used to calculate the amount of energy stored within a capacitor’s electric field. 

W represents energy, C is capacitance and V is voltage. 

Let’s take a look at how capacitance affects the magnitude of a capacitor’s electric field. 

Capacitance is a crucial part of a capacitor which determines its ability to store electrical energy in an electric field.

As you just saw before, when a voltage is applied to a capacitor, a fixed amount of positive (q+) and negative (q-) charges build up on either plate of the capacitor. 

Using the value of voltage (V) and total amount of charge (q), we can calculate the total capacitance (C). 

Different types of capacitor

In this article we have been discussing the most basic type of capacitor, known as a parallel-plate capacitor whose dielectric is just  a vacuum (air). 

But, there are many different types of capacitor available. Below is a list of the most common;

• Ceramic 
• Film and Paper
• Aluminum, Tantalum and Niobium 
• Polymer
• Silver mica, glass

Capacitors are usually named after the material used for their dielectric.

Each of these capacitors will vary in either size, dielectric, material used for anode (positive plate), and construction of cathode (negative plate). 

Things like the area of the plates, distance between the plates, type of dielectric used, dielectric constant, etc, all play a role in determining a capacitor’s total capacitance. 

Changing the capacitance will directly impact the amount of energy that will be stored in the capacitor’s electric field. 

From the equation above we can deduce that the higher the capacitance, the higher the energy storage capability for that capacitor and vice versa.

Is the energy stored in the capacitor permanent?

No, the energy stored in a capacitor’s electric field is not permanent. 

When the capacitor is connected to a battery, charges build up on both plates until it reaches a maximum value.

This does not happen instantaneously but takes a certain amount of time which is known as the Rate of Charge. 

Now, if we disconnect the voltage source that charged the capacitor, the capacitor is going to discharge the charge (or energy).

This does not happen instantaneously either, but over time. 

This is known as Discharge rate, which defines the time it takes for a capacitor to release all its charge and voltage.

So, the energy in a capacitor’s electric field stays at a constant level as long as there is a voltage present. When voltage is removed, the energy will drain over time. 

What component stores energy in the form of a magnetic field?

Ok, so a capacitor stores energy in the form of an electric field. 

But, is there a component that stores energy in the form of a magnetic field?

Yes, an Inductor is a passive electrical component that stores its energy in the form of a magnetic field when subject to a current. 

They are also referred to as a Coil, Choke, or Reactor.

The post Does a capacitor store energy in the form of a magnetic field? appeared first on Electronic Guidebook.

From electromagnetism in things like motors, electric generators, and transformers to medical applications like Magnetic Resonance Imaging machines (MRI).

We even use the principles of magnetism in public transport. The Maglev Floating train uses magnetism as a means of transporting travelers to their respective destinations. 

In its early days the magnet was developed to be used as a compass. 

Nowadays, magnets lend a helpful hand to holding our devices such as the smartphone when you commute in our cars. Are magnetic phone mounts safe for holding an iphone? 

Magnets do have a bad reputation when they are mentioned in the same sentence as electronic devices. There is a misconception that magnets will damage every electronic device out there.

However, this a myth. While, there are certain aspects that magnets do affect, generally magnets will not damage electronic equipment. But, it all depends on the size and strength of the magnet in question of course.

I shall go over major concerns you might have, and debunk any myths.

Do magnets affect electronics?

The most important question is whether magnets affect electronics. You might have seen videos of people taking magnets and running them across television sets and the consequently seeing the image of the television set get distorted.

The thing is that this was the case for older Cathode Ray Tube (CRT) televisions which were affected by a magnetic field. This is what has probably led many to believe that magnets will damage most  electronic devices.

Electronics have evolved drastically over the years, and many components and fundamental principles they would have used to make devices 20 years ago are much different now.

The television is the perfect example. As I mentioned above, older CRT televisions were affected by magnets and this is because of the fundamental way the CRT works. 

Without getting into too much detail, a magnetic field is used to direct electrons toward the screen. By introducing another magnet in front of the screen it is messing with the internal magnetic field of the television and redirecting the electrons from where they need to go and thus distorting the image.

When you leave the magnet in front of the screen for too long, it makes that part of the screen magnetic therefore distorting that part of the screen permanently. 

The newer televisions used LED technology and do not use the older method of a magnetic field and electrons. So, running a magnet across the screen will not distort the image. 

Computer hard disks are another electronic device that could potentially get affected by magnets.A lot of movies depict hackers erasing information from hard disks. It does take quite a strong magnet to do so. 

Small magnets will not have that much of an impact. I will discuss the different types of magnets later.

Another important device that is affected by a magnet is a Pacemaker. This is a device that is implanted in a patient to help with heart rhythm disturbances.

They are placed under the skin near the chest area. The way the work is by producing electrical impulses which regulates the activity of the heart.

The presence of a magnet field can throw the pacemaker into a special mode which is determined by the manufacturer.

This is not an ideal case and once the magnet is removed, the pacemaker returns to normal operation. So maintain safe distances from magnets if you have a pacemaker.

There are many devices that will be impacted by a magnetic field, either temporarily or permanently.

Other notable electronic devices that could be possibly be thrown into hysteria by a magnetic field are magnetic credit cards, and hearing aids.

Why are these devices affected?

The common theme with the devices that I have mentioned above is that they all have some sort of magnetic storage or work on the principles of magnetism.

Things  like inductance inside electronics circuitry can be influenced by the presence of a magnet. It could induce a pulsing current that could raise the voltage in some components. But, this is all temporary and will not damage the equipment long term.

Another factor to take into consideration, is that if a strong magnet is close to a device, it could slightly magnetize some steel components inside, which in turn will make them  like weaker magnets. This could potentially affect the operation of parts of the circuit. 

There are a range of electronic components that get impacted due to the way they work. 

Relays – The way a relay works is by using a magnet to move a piece of ferrous material to close a switch. The introduction of a magnetic field might cause relay to close, open or get stuck in its current position unnecessarily. 

Hall sensors – Are electronic sensors that measure magnetic fields. They are used in many motors. So, if there is a magnetic field that is not meant to be there, it could ruin the readings. 

Motors – Use the principle of magnetism to function. Magnets could potentially affect them, but they have decent shielding.

Types of Magnets

So, we have seen that there are certain devices that are more susceptible to the general household magnet due to the fact of the technology and principle behind how they work.

Saying this however, if the magnet is strong enough, it will do damage to most devices. One of the strongest magnets known to mankind is the neodymium magnet.

Neodymium magnets are part of the rare earth family of magnets because their main element is a rare earth element.

Another way to create a really strong magnetic field does not even use any magnets. This phenomena is known as electromagnetism. When electricity flows along a wire it creates a magnetic field. Electromagnets are strong enough to pick up cars (depending on their size of course).

Time is another factor to consider. The longer a device is exposed under high intensity magnetic fields the likeliness of damage is increased. Many internal parts could get magnetized themselves and change the inner works of that electronic device. 

So, while most devices will not get affected by your everyday magnet, the best practice is to avoid having them exposed for long periods near them.

Also if you happen to have access to any rare earth magnets such as the Neodymium magnet, as a precaution, keep them away from electronic equipment.

Inside the Iphone

Many, if not most, smartphones such as the Iphone have magnets embedded inside them.

The speaker, vibration motor, camera are some of the modules inside a smartphone that use magnets. Nowadays wireless charging is achieved by means of electromagnetic induction. 

The magnets used inside a smartphone are neodymium magnets. But, these magnets are small and their magnetic field is not enough to disrupt other electronic devices. 

These magnets do not do damage or affect the capabilities of a smartphone’s internal circuitry. In fact they serve a purpose and provide a valuable function. 

You use and keep your smartphone around other electronic devices without affecting them. Most people keep their smartphones and credit cards together without harming the function of the credit card.

The Magnetic Phone Mount

The practicality of the magnetic phone mount for an iphone can be seen in many areas. 

If you are someone who receives or makes a lot of calls, the hands free feature that a magnetic mount offers can be be very handy. Even using voice to text will be made easier.

Navigation will be greatly enhanced as you will not have to juggle your phone trying to see where your next turn is, as the mount will provide a secure spot where you can view the screen.

Using a magnetic mount for your Iphone will provide a safe and secure haven, and eliminate you having to constantly find a nook or cranny to jam your phone into so it will not be dislodged when your car hits a bump.

How do they work?

So how does a magnetic phone mount work?

Most magnet mounts work in two parts; You have to stick metal plates to your Iphone and use a mount embedded with magnets.

The metal plates are included with the magnet mount when you purchase it (do not worry you do not have to go scavenging for metal plates).

If, however, you do not want to stick metal plates to your phone or phone case and ruin it’s aesthetics, you have another option. That option is to use a metal case. 

There are many benefits for using a metal case over sticking metal plates on your phone. 

You won’t ruin the aesthetics of your beautiful Iphone, you will not affect wireless charging (because you can remove the case when you need to charge but cannot remove the metal plates you stuck on), and when you do decide to remove those metal plates you won’t be stuck with any residue from the glue.

Type of magnets used

But, let us get back to the main question at hand. We have seen that it takes large strong magnets (and magnetic fields) as well as long exposure times to really do damage to your electronic devices. So will these magnetic phone mounts be safe for you iphone? 

Many of the best available magnetic mounts do use powerful magnets like the Neodymium magnet.

However, fear not, these are not large enough (therefore their magnetic fields are not considerable enough to worry about) to do any damage to your Iphone. 

As I already mentioned, smartphones already contain tiny neodymium magnets. 

So, you should only be concerned with the size of these magnets. Choose a magnetic phone mounts that use fewer and smaller magnets. As you increase the number of magnets you also increase the magnetic field.

Will it affect the Iphones…

Memory 

You saw earlier in this article how movies would show hackers trying to erase information using magnets.

The case with computer storage is that it uses a magnetic field to store information. Even then you would need quite a large and strong magnet to completely wipe out any information.

Iphones and other smartphones alike do not have Hard Disk Drives, and do not use magnet fields to store data. So, a magnet cannot disrupt or wipe out information. 

Iphones use storage chips which are similar to flash memory to store data.

The first generation Iphone (Iphone classic) did have a Hard Disk Drive, which could have potentially been affected by a strong magnetic field. So a magnetic phone mount would not really have been safe.

Display / Screen

Going back to old school CRT television and the principles it used to achieve an image. It used a magnetic field to focus beams of electrons. So introducing an external magnetic field would directly affect it.

Today’s smartphones use electricity, LED’s, and capacitance to provide a display for it’s users. So magnets will not hinder its performance. 

But, highlighting a major point, keep large, strong magnets away from them.

Navigation (GPS and Compass)

Another major concern that you might have is, will it affect your GPS when using it for navigation.

The way your phone works to figure out your position on earth is by working in conjunction with satellites. It is all based on satellite coordinates and math equations to determine your location. There is no magnetic field involved to figure where you are, so a magnetic car mount will not affect your navigation.

When it comes to the compass however, the presence of a magnetic field might affect the way it works. But, it only gets affected in the presence of a magnetic field. As soon as the magnet is removed, the compass goes back to working normally. 

The compass on your phone uses a  sensor (magnetometer) to detect the earth’s magnetic field. It does this to determine the phones orientation relative to the magnetic field.  

The good news is that your navigation applications do not need the compass functionality. 

So, when using your phone on a magnetic mount in your car to figure out how to get to your next destination, the GPS on your Iphone will not get affected.

Battery

With the battery in a smartphone, many people worry that a magnetic phone mount will discharge the battery faster.

Again, it comes down to the size of the magnet and its strength. A considerably large magnet might interfere with certain internal components causing the battery to drain quicker.

However, the size of the magnets used in magnetic car mounts are not large enough to cause any significant discharging of the smartphone’s battery.

The most common use for a phone car mount is to provide a secure place for your phone while using a navigation app on your Iphone. Most of these navigation apps use a lot of power which is probably a greater cause of your battery levels dropping than the magnetic car mount. 

Speaker

Last but not least, the speaker. Now speakers do work using magnets. So will an external magnet ruin your sound quality?

Because the magnetic car mounts use small magnets, and there is a barrier between them and your Iphone speaker, the sound of your speaker will not get affected.

Conclusion

So, are magnetic phone mounts safe for an Iphone? 

The answer is yes. 

Even though your compass might be affected in the presence of a magnetic field, when that magnetic field is removed the compass will return to its normal operation. There is no permanent damage. 

The times you will be using the magnetic phone mount, will not require the function of the compass anyway.

Also, if you opt to use a metal case, it will act as a minor barrier between your phone and the magnetic phone mount. So your Iphone will be safe. 

Saying that, however, common sense needs to be used. While, your everyday magnet or even smaller neodymium magnets cannot do damage to your smartphone, you do not want to leave them exposed to them for long periods of time.

Keep them away from larger, stronger magnets at all costs.

Magnetic Mounts for an Iphone

When considering what magnetic phone mount to get, some stand out among the rest. There are certain things to consider when choosing the perfect mount. 

Secure/Sturdiness – You want the magnets to provide enough of strength, stability and sturdiness so that when you are driving your car and hit a bump or pothole, your phone will not fall off or move from its position.

Flexibility – The ball and joint mechanism that allows you to swivel the phone, should be flexible enough so that you can view your phone from any angle. It should be strong and stiff enough that it does not move when you do not want it to.

Compact – It should be compact so that it does not take a lot of space. The last thing you want is some massive contraption blocking you from seeing the road.

Durable – The materials should be durable and long lasting. 

Easy Installation – Who wants to spend hours setting up a magnetic phone mount? Nobody. Therefore it should be easy enough to install without having to read 20 pages of a manual. 

It should also be versatile enough to install it anywhere as well.

I have chosen the bottom 3 magnetic phone mounts, because they satisfy all of the above criteria.

TOTU MAGNETIC PHONE MOUNT

RAV POWER MAGNETIC PHONE MOUNT

RAXFLY MAGNETIC PHONE MOUNT

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