# Determining The Magnetic Saturation of A Soft Iron Magnetic Core

• Yrton
In summary: I mean "low power"...transitioning between fields.Ah, so it's more of a learning/academic project, rather than an application. That's totally fine.It is much more difficult (takes a lot more power) to saturate an open core versus a closed core. An open core includes some of the magnetic path length in air, where the mu is the free space mu. The "reluctance" of the free-space gap is much higher than the reluctance of the magnetic material, so the overall B that you can generate in the magnetic path is much lower.In a closed magnetic circuit like with a toroid, saturation is much more of a concern
Yrton
Hello friends.
I know there a lot of complex mathematic involved in this subject and I'm not currently very knowledgeable in that area but, in simple terms, what would be the simplest way (theoretical or practical) to determine the magnetic saturation of a cylindrical soft iron magnetic core inside an electromagnet? How much magnetic field is needed by the coil in order to saturate this piece?
Here are the dimensions of the core:
diameter = 0.5"
length = 2.5"
Thanks.

Yrton said:
Hello friends.
I know there a lot of complex mathematic involved in this subject and I'm not currently very knowledgeable in that area but, in simple terms, what would be the simplest way (theoretical or practical) to determine the magnetic saturation of a cylindrical soft iron magnetic core inside an electromagnet? How much magnetic field is needed by the coil in order to saturate this piece?
Here are the dimensions of the core:
diameter = 0.5"
length = 2.5"
Thanks.
What shape is the core? Is it closed or open? Do you have a datasheet for it? Can you post a picture?

Do you have a bobbin in mind for this core? Do you have a winding machine, or will you be winding the bobbin by hand?

You can use a signal generator and a 2-channel oscilloscope to plot the saturation curve, as long as the signal generator has a low enough output impedance and you can wind enough turns on a test bobbin. If you need more power to saturate the core, you can wire up a simple amplifier circuit to give you a higher current.

What is the core material, and at what frequencies are you going to use it?

berkeman said:
What shape is the core? Is it closed or open? Do you have a datasheet for it? Can you post a picture?

Do you have a bobbin in mind for this core? Do you have a winding machine, or will you be winding the bobbin by hand?

You can use a signal generator and a 2-channel oscilloscope to plot the saturation curve, as long as the signal generator has a low enough output impedance and you can wind enough turns on a test bobbin. If you need more power to saturate the core, you can wire up a simple amplifier circuit to give you a higher current.

What is the core material, and at what frequencies are you going to use it?

The core is cylindrical. I'm not sure what you mean by "closed or open". There's no datasheet as I'm designing everything from scratch. No photos available yet.

I have no oscilloscope.

I'm using soft iron for the core. I may want to use a capacitor to create high current.

Yrton said:
The core is cylindrical. I'm not sure what you mean by "closed or open".
A cylindrical finite core is open. It is extremely unlikely you will saturate it.

Can you post more about your application? What is the power source? How many turns on the bobbin? What frequency? What is the core material?

Yrton said:
I may want to use a capacitor to create high current.
BTW, the verb phrase "wanna" carries negative connotations for some folks. It would be better if you substituted "want to" instead. Just saying...

Also, Is this a DC electromagnet application? Maybe I misinterpreted your OP...

sophiecentaur
berkeman said:
A cylindrical finite core is open. It is extremely unlikely you will saturate it.

Can you post more about your application? What is the power source? How many turns on the bobbin? What frequency? What is the core material?

"Extremely unlikely" but how is the saturation calculated/measure sans the oscilloscopes?
The purpose of this experiment is for me to research and learn about the concept of magnetic saturation in ferrite objects as I wasn't able to find any simplified material regarding this online.
I do not have a specific application for this project in mind. I've already mentioned that the core material is soft iron as it's not very expensive to buy.

Yrton said:
"Extremely unlikely" but how is the saturation calculated/measure sans the oscilloscopes?
The purpose of this experiment is for me to research and learn about the concept of magnetic saturation in ferrite objects as I wasn't able to find any simplified material regarding this online.
Ah, so it's more of a learning/academic project, rather than an application. That's totally fine.

It is much more difficult (takes a lot more power) to saturate an open core versus a closed core. An open core includes some of the magnetic path length in air, where the mu is the free space mu. The "reluctance" of the free-space gap is much higher than the reluctance of the magnetic material, so the overall B that you can generate in the magnetic path is much lower.

In a closed magnetic circuit like with a toroid, saturation is much more of a concern for normal circuit operation. There is no gap in the magnetic path, so saturation happens at a lower value of amp-turns excitation.

berkeman said:
Ah, so it's more of a learning/academic project, rather than an application. That's totally fine.

It is much more difficult (takes a lot more power) to saturate an open core versus a closed core. An open core includes some of the magnetic path length in air, where the mu is the free space mu. The "reluctance" of the free-space gap is much higher than the reluctance of the magnetic material, so the overall B that you can generate in the magnetic path is much lower.

In a closed magnetic circuit like with a toroid, saturation is much more of a concern for normal circuit operation. There is no gap in the magnetic path, so saturation happens at a lower value of amp-turns excitation.

Thanks for the explanations. I'm still open to get more insights into this subject.

## 1. What is the purpose of determining the magnetic saturation of a soft iron magnetic core?

The purpose of determining the magnetic saturation of a soft iron magnetic core is to understand the maximum amount of magnetic flux that the core can hold before it becomes completely saturated. This information is important in designing and optimizing magnetic circuits for various applications.

## 2. How is the magnetic saturation of a soft iron magnetic core measured?

The magnetic saturation of a soft iron magnetic core is typically measured using a magnetometer or a gaussmeter. These instruments can accurately measure the magnetic flux density in the core and determine when it reaches its maximum saturation point.

## 3. What factors affect the magnetic saturation of a soft iron magnetic core?

The magnetic saturation of a soft iron magnetic core can be affected by several factors, including the material composition of the core, its shape and size, the strength of the applied magnetic field, and the temperature of the core. These factors can impact the core's ability to hold magnetic flux and reach its saturation point.

## 4. Why is it important to know the magnetic saturation of a soft iron magnetic core?

Knowing the magnetic saturation of a soft iron magnetic core is crucial in designing efficient and reliable magnetic circuits. It allows engineers to select the appropriate core material and size, as well as determine the maximum operating conditions for the core. This information is essential in ensuring the proper functioning and longevity of magnetic devices.

## 5. Can the magnetic saturation of a soft iron magnetic core change over time?

Yes, the magnetic saturation of a soft iron magnetic core can change over time due to factors such as temperature, mechanical stress, and exposure to external magnetic fields. This is why it is important to regularly monitor and test the saturation level of the core to ensure its optimal performance.

• Electromagnetism
Replies
43
Views
1K
• Electromagnetism
Replies
1
Views
3K
• Electromagnetism
Replies
3
Views
1K
• Electromagnetism
Replies
22
Views
6K
• Electrical Engineering
Replies
11
Views
3K
• Electromagnetism
Replies
7
Views
2K
• Electromagnetism
Replies
14
Views
6K
• Electrical Engineering
Replies
76
Views
7K
• Electromagnetism
Replies
1
Views
2K
• Electromagnetism
Replies
8
Views
10K