Answer / jude finney

speed of the motor can be varied in two methods
1)by armature voltage control method
2)by field voltage control method

Answer / m raviteja

by varying the armature resistance and field resistance

Answer / uma

speed of dc motor can be varied by using v/f control. that
is either by changing the armature voltage or frequency.

Answer / akhilesh

Please use DC Drive

Answer / hm

@ uma : What is the concept of frequency in DC supply ??

dc motor speed can be varried by
1. armature voltage control
2. field flux control

also u can control speed by PWM (Pulse Width Modulation) by
varying the duty cycle.

Answer / ganguly

there are two types of speed control for dc motor

1. armature control method
by connecting the additional resistance to the armature,
but this will use below rated seeds only
2.field controlmethod
by connecting the resistance to the field
but this will use above rated speeds only

if a 3phase motor runnig in star delta starter with full load of its,and its rated 15 amps.now we conneted over load thermal relay at its main contactor,here what will be our amps sittings?

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