Inductance Calculator
L= (d^2 * n^2)/(18d+40l)
where:
L is inductance in micro Henrys,
d is coil diameter in inches,
l is coil length in inches, and
n is number of turns.
Inductance Calculator
L= (d^2 * n^2)/(18d+40l)
where:
L is inductance in micro Henrys,
d is coil diameter in inches,
l is coil length in inches, and
n is number of turns.
DJMota says
Great tool, but it could be with metric units for non-English people.
Having to change between units is annoying.
Greetings.
Бойчо says
1 inch = 25,4 mm
marcelino ibrahim says
hi sir thx for sharing your knowledge I have a question about the inductance calculator it has the coil diameter and length and number of turns so if I use whatever wire gauge it will give the same result?
and another question I have if u can answer it is that lets say we have a 1micro Henry made of air core and another 1 micro Henry made of ferrite core they will perform the same as long as the value is one micro Henry?
Swagatam says
Thanks Marcelino, the wire thickness will decide the amount of current the coil can handle. If the current is minimal then any minimum wire gauge can be used and all will give the same results. I don’t think an air core and a ferrite core inductor will produce the same results, because magnetic characteristics will be different for air and ferrite.
Chandra Shekhar Gupta says
Dear friend,
As you provided the calculator for a given coil to calculate the inductance. I wish for a calculator to workout
a new given inductance.
Swagatam says
Dear Chandra, please check the software, I have updated it appropriately…
Tapiwa Akin says
hi . how do i get in touch with you via email. I need help on a school project that includes electromagnetism
Swagatam says
Tapiwa, you can explain it here through comments, if possible I’ll try to help….
Tapiwa says
My project involves controlling the closure of a car door to prevent it from slamming using electromagnet.if it’s moving too fast it can be repelled for a second and after the delay it gets attracted .so how can I make the magnet change polarity for jus a moment to repel an object and then attract it again.if you can help with a circuit or a similar one and things you think I might need.im sort of stuck
Swagatam says
The polarity of electromagnet can be changed with a DPDT relay. Trigger the relay with a reed switch as soon as the door is about to slam so that the DPDT relay triggers and reverses the electromagnet polarity.
Tapiwa says
so is a h bridge dual motor driver necessary and do you happen to have a circuit that may be similar and involves a reed switch and DPDT relay
Swagatam says
only a DPDT relay and a reed switch or a micro switch is all that’s required for changing the electromagnet polarity..if possible I’ll try to draw it for you.
Rabin Tarafdar says
Most of your articles easy to follow. One problem we often face is where to get spares particularly IC in kolkata
market. where to get charts of relative permeability.
Thanks a lot.
Rabin Tarafdar
Swagatam says
Thank you Rabin, I am based in Mumbai so I don’t know much regarding the parts availability in Kolkata…I would rather recommend buying from an online shop, from where you can buy any desired part as per your requirement.
Some information regarding relative permeability can be learned from this online post:
https://en.wikipedia.org/wiki/Permeability_(electromagnetism)