Misalai na Maitar Da DC Motor?

DC Motor na iya aiki ta yin daidai?

Takaitaccen DC Motor

DC Motor shine karamin yanayi mai tsabta da ke taimaka wajen abindu masu sauri a kan alama mai tsabta da kuma tasirin magana.

DC motors suna da muhimmanci a fannin jamiyar zaman. Fahimtarsa na iya aiki na DC motor, wanda ake nuna a cikin wannan takar, tana faruwa ne daga takaitaccen karamin yanayi na musamman.

Takaitaccen karamin yanayi na DC motor tana da armature mai tsabta, wanda ake shiga a kan ci gaba da commutator segments da kuma brushes. Armature tana da shiga a kan gabashin north pole da south pole na permanent magnet ko electromagnet kamar yadda ake nuna a cikin diagram.

Idan tsabta mai karfi yake shiga a kan armature, zai iya samun lafiya daga alama mai tsabta da ke cikin yankin. Don in fahimtar daidai ya kamata a yi fahimta Fleming’s left-hand rule, wanda yake taimaka wajen tabbatar da hakan da lafiya take aiki a kan armature.

Idan karamin yanayi mai tsabta yake shiga a kan alama mai tsabta perpendicularly, zai iya samun lafiya a kan yawan da yake shiga perpendicular zuwa labari da alama mai tsabta da karamin yanayi mai tsabta.

Fleming’s Left-Hand Rule zai iya tabbatar da hakan da mutanen motor. Wannan rule yana cewa idan muka bada index finger, middle finger da thumb da hankali a kan harkokin mika perpendicularly, middle finger yana da hakan da tsabtan karamin yanayi, index finger yana da hakan da alama mai tsabta, north to south pole, thumb yana nuna hakan da lafiya mai aiki.

Don in fahimta daidai ya kamata a yi fahimta magnitude of the force, bane a duba diagram da ke cikin.

A sani da duk da za a yi fahimta cewa idan charge dq yake shiga a kan velocity ‘v’ a kan alama E, da kuma B, Lorentz Force dF yake samu ga charge yana nufin:

Don iya aiki na DC motor, E = 0.

Yana nufin cross product of dq v da magnetic field B.

Duk da dL shine length of the conductor carrying charge q.

Daga diagram da farko, ana iya fahimtar da takaitaccen DC motor yana nufin cewa hakan da tsabta yake shiga a kan armature conductor at all instance yana perpendicular zuwa alama. Saboda haka, lafiya yake aiki a kan armature conductor a kan yawan da yake shiga perpendicular zuwa uniform field, da kuma tsabta yana daidai.

Saboda haka idan muka nemi tsabtan a kan hankalin armature conductor I, da kuma tsabtan a kan yankin armature conductor -I, saboda suka shiga a kan labari da yawa.

Duk da lafiya a kan hankalin armature conductor,

Duk da lafiya a kan yankin armature conductor,

Saboda haka, ana iya fahimtar da duk da lafiya a kan either side yana daidai amma yana da labari da yawa. Saboda hankalin karamin yanayi suna da shiga a kan yawan da yawa, duk da lafiya yawa suna bayyana rotational force ko torque wanda yake shiga a kan rotation of the armature conductor.

Za a duba expression of torque idan armature turn create an angle of α (alpha) with its initial position. Torque produced yana nufin: 

Anna α (alpha) shine angle between the plane of the armature turn and the plane of reference or the initial position of the armature which is here along the direction of magnetic field.

Presence of the term cosα in the torque equation very well signifies that unlike force the torque at all position is not the same. It, in fact, varies with the variation of the angle α (alpha). To explain the variation of torque and the principle behind the rotation of the motor let us do a stepwise analysis.

Step 1:

Initially considering the armature is in its starting point or reference position where the angle α = 0.

Since, α = 0, the term cos α = 1, or the maximum value, hence torque at this position is maximum given by τ = BILw. This high starting torque helps in overcoming the initial inertia of rest of the armature and sets it into the rotation.

Step 2:

Once the armature sets in motion, the angle α between the actual position of the armature and its initial reference position goes on increasing in the path of its rotation until it becomes 90 ^o from its initial position. Consequently, the term cosα decreases and also the value of torque.

The torque in this case is given by τ = BILwcosα which is less than BIL w when α is greater than 0o.

Step 3:

In the path of the rotation of the armature a point is reached where the actual position of the rotor is exactly perpendicular to its initial position, i.e. α = 90 ^o, and as a result the term cosα = 0.

The torque acting on the conductor at this position is given by,

i.e. virtually no rotating torque acts on the armature at this instance. But still the armature does not come to a standstill, this is because of the fact that the operation of DC motor has been engineered in such a way that the inertia of motion at this point is just enough to overcome this point of null torque. 

Once the rotor crosses over this position the angle between the actual position of the armature and the initial plane again decreases and torque starts acting on it again.