Help with Electromagnet Project Design

[rocketnukem]

I was referd to this forum from a friend and I have been reading some of them and I think you guys can help me and I would be very happy if you could.

I was taking a electormagnitism physics class in school, calc based, and I had this idea for a project. I know that to calculate the magnetic field that is F=I*L*B*sin(thata) and the magnetic field of a solenoid is B=(u*n*I)/(2R) and n=turns/length. The question I have is how do I calculate the number of turns a solenoid needs when it has an iron core and what core to choose? I have been reading outside of class about fearite and iron powder cores and it seems they have a class for each but I don't understand them. I havn't even decided if I should use a tipical solenoid or a toroid either.

I am trying to find out if I can make a electromagnet that is roughly 5" high, 11" wide, and
12" long(this may have to be shorter), that runs on 20 amps, 12-24V DC, and has a 25,000-60,000N pull force on it (would really like to hit that max but not being picky). I realize I have taken only one physics class about magnetics and this sound rediculus so if it can't be done it wont't hurt my fealings none. Thanks for any input.

 

[elegysix]

Here's a link talking about how to calculate the magnetic field with an iron core,

http://en.wikipedia.org/wiki/Electr..._.E2.80.93_the_constant_B_field_approximation

From that, it talks some about calculating the force on another magnet.

I think 25000 - 60000 N is really high, but with enough turns I'm sure it can be done lol
I don't know if you could manage to fit those dimensions though.

That would be pretty dangerous to use, what do you need it for?

 

[rocketnukem]

Would multiple smaller electromagnets in a case that size work better? Would the force of each magent add up or does it not work that way?

 

[elegysix]

I think they add, just as adding turns to one coil adds B field. But it will be less efficient because there will be some separation between the coils.

I think the best way would just be a single coil with as many turns as necessary.

I suggest building it, measuring the strength with some number of turns, and measuring again with x many more turns. Then you could do some algebra to figure out approximately how many turns you need.

That article says something about saturation of the core and becoming nonlinear, but I wouldn't worry about that for now.

 

[sardar]

Hello,

First of all, it's great that you are taking the initiative to design an electromagnet project and are seeking help from others. It's important to have a good understanding of the principles and calculations involved in order to design a successful project.

To start, it's important to determine the purpose of your project. Are you trying to create a strong electromagnet for lifting heavy objects or for other applications? This will help guide your design decisions.

In terms of calculating the number of turns for a solenoid with an iron core, you will need to consider the permeability of the core material. Iron has a higher permeability than air, so it will increase the magnetic field strength. However, the exact number of turns required will also depend on the desired strength of the magnetic field and the current you are using.

As for the type of core to choose, ferrite and iron powder cores have different properties and are used for different purposes. Ferrite cores have a high frequency range and are commonly used in electronic devices, while iron powder cores have a lower frequency range and are often used in power applications. It's important to research and understand the properties of each type of core before making a decision.

In terms of the design of your electromagnet, it's important to consider the size and shape of the magnet, as well as the materials used. A solenoid may be more suitable for creating a strong magnetic field in a specific direction, while a toroid may be better for creating a more uniform field. Again, this will depend on the purpose of your project.

In terms of your desired specifications for the electromagnet, it's important to note that the strength of the magnetic field is directly proportional to the current and the number of turns. So in order to achieve a stronger pull force, you will need to increase either the current or the number of turns, or both. It's also important to consider the power supply and the limitations of the materials you are using.

Overall, it's important to have a clear understanding of the principles and calculations involved in designing an electromagnet project. It may also be helpful to consult with a physics teacher or a professional in the field to ensure that your design is feasible and safe. Good luck with your project!