How to Design a Solenoid for an Electric Door Lock Releaser?

[I_am_learning]

I am trying to make a an electric door lock releaser. I am going to use a solenoid to make an electromagnet that will pull down a handle to release the lock. The electromagnet has to act from a distance of 1 cm. And it has to impart a force of at least 10 N. The problem is to design the electromagnet to operate at 12v. I mean to ask, how many turns of wire?, what diameter of wire and the iron-core?. Whats the method to find them?

 

[I_am_learning]

Put it in short my question is--
, Given a solenoid, you can find the magnetic field strength by B = uNI.
But How do I calculate how much force this field will impart in a piece of iron some distance away?

 

[oswaler]

Thank you for sharing your practical problem with me. I can suggest some considerations for designing your solenoid-based electric door lock releaser.

Firstly, the number of turns of wire, the diameter of the wire, and the iron-core all play a crucial role in determining the strength and efficiency of your electromagnet. To determine these values, you will need to consider the following factors:

1. Desired force: As you mentioned, your solenoid needs to impart a force of at least 10 N. This is an important factor in determining the number of turns and diameter of wire.

2. Power supply: You have mentioned that your solenoid needs to operate at 12v. This voltage will also impact the design of your electromagnet.

3. Distance: Your solenoid needs to act from a distance of 1 cm. This will also affect the design of your electromagnet as the strength of the magnetic field decreases with distance.

To determine the number of turns of wire, you can use the formula N = (μ0 * μr * A * n^2)/l, where N is the number of turns, μ0 is the permeability of free space, μr is the relative permeability of the core material, A is the cross-sectional area of the core, n is the number of turns per unit length, and l is the length of the solenoid.

To determine the diameter of wire, you can use the formula d = sqrt((4 * N * I * r)/π * μ0 * μr), where d is the diameter of the wire, N is the number of turns, I is the current, r is the radius of the solenoid, and μ0 and μr are the same as before.

To determine the iron-core, you will need to consider the desired force and the magnetic properties of the core material. A material with a high relative permeability will increase the strength of your electromagnet.

I hope this helps you in designing your solenoid-based electric door lock releaser. It is important to note that these calculations are based on ideal conditions and may need to be adjusted based on real-world factors. It is also important to consider safety precautions when working with electricity and electromagnets. I wish you success in your project.