What is the resistance of armature?

Armature Winding resistance is the ohmic resistance of the copper winding wires. A brush is used to provide electrical contact between the stationary contacts and moving parts like commutator or slip rings.

What is the formula of armature resistance?

V − O = I a R a ∴ I a = V R a . As the resistance of a motor armature may be less than an ohm, then the armature current at starting if the armature applied voltage were 230 V would be in excess of 230 A.

What is field resistance and armature resistance?

Speed Control of DC Motor: Armature Resistance Control and Field Flux Control. The dc motor converts mechanical power into dc electrical power. Here equation (1) shows the speed is dependent upon the supply voltage V, the armature circuit resistance Ra and the field flux ϕ, which is produced by the field current.

What is the relation between armature current and torque?

We know that torque is directly proportional to the product of armature current and field flux, Ta ∝ ɸ. Ia. In DC series motors, field winding is connected in series with the armature, i.e. Ia = If. Therefore, before magnetic saturation of the field, flux ɸ is directly proportional to Ia.

What is armature current?

In electrical engineering, the armature is the winding (or set of windings) of an electric machine which carries alternating current. The first is to carry current across the field, thus creating shaft torque in a rotating machine or force in a linear machine.

How do you calculate armature current?

Therefore, Average armature current, Motor emf, Ia=196.01−804=23.003AEa=Km. ωm=Km2π×140060Km=80×602π×1400=0.546V−s/rador 0.546Nm/A.

Why is armature resistance low in DC motor?

There need to be sufficient winding resistance within the field winding to restrict the current drift. However, it is necessary that the armature resistance is low because the DC generator generates excessive currents and any DC armature resistance will cause decrease in generator performance.

Why is field resistance higher than armature resistance?

What is the relation between armature torque and armature current in dc series motor?

The torque in case of a dc series motor is proportional to the square of the armature current. This relation is parabolic in nature as shown in the figure. As load increases, armature current increases and torque produced increases proportional to the square of the armature current up to a particular limitation.

What is the relation between current and torque?

Mechanical or load torque is proportional to the product of force and distance. Motor current varies in relation to the amount of load torque applied. When a motor is running in steady state, the armature current is constant, and the electrical torque is equal and opposite of the mechanical torque.

What is the relationship between the armature current and the field current?

By definition field current is the one that produces magnetic field required by the machine, and armature current is the current induced in the windings by the created mmf. Based on this, DC current on the rotor is field current, and induced AC current in the stator is armature current.

What is the relationship of the armature voltage and field current?

Based on the experiment I conducted, the data shows that the armature voltage is directly proportional to the field current.