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

IN THE CASE OF AN ELCB, IF THERE IS ANY UNSTABILITY BETWEEN PHASE AND NEUTRAL IT MAY TRIP. BUT MY QUESTION IS WHEN A LOAD IS CONNECTED IN BETWEEN P AND N, THE LOAD CONSUMES SOME POWER AND THERE IS A DIFFERENCE IN NEUTRAL WITH RESPECT TO THE PHASE. THUS ACCORDING TO ME, THE ELCB WILL AUTOMATICALLY OPERATES WHEN EVER THE LOAD CONSUMES-- I KNOW IT IS WRONG. BUT THE SOLUTION IS?????????

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