Question

Torque in DC Motor? Can someone please explain to me in detail about theses laws here: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/motdc.html#c1

It's confusing to me...

Answer 1

similar to ac motor where direction of the current decides the direction of magnetic flux thus the coil moves
here cummulator changes direction of current after half revolutin so direction of magnetic flux changes thus motion contineus. ..

Answer 2

The the torque generated in a motor generally is dependent on the magneti flux?

Answer 3

yup the magnetic flux. .
the coil itself act as magnet as the same ends of magnet repells similarly magnet repells coil away so coil rotates at its axis and after half revolution the cummulator changes direction of current thus again coil faces opposite cend of magnet so it repells coil again and process go on. . .

Answer 4

Yea, I know that point. I'm trying to calculate the torque produced from the repulsion/attraction of the coil & magnet.

Answer 5

how can you calculate it??

Answer 6

I looked online and found the torque equation check out this link: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/motdc.html#c1

Go the the final slide and you're find what I mean. I didn't really understand the equation...

Answer 7

well i can explain what is it
i is current B is magnetic field A is tha area under the coil ( length * width). sin is the angle of coil w.r.t. magnetic flux

Answer 8

Oh,ok! I'm trying to build a simple DC motor and I'll try to study this more and more.

But the angle is constantly changing... When current is applied what then :P ?

Answer 9

torque is maximum when angle is zero. . that is sin0=1 and minimum when 90.
when it is at 90 that is half revolution is completed then again current is applied in opposite direction :P

Answer 10

Very interesting! Thanks!