What is the necessity of starter in DC motor ?
The voltage equation of dc motor is
V = Eb + IaRa
at start Eb = 0, V= IaRa
Ia = V / Ra. (Ra alone limits the Ia)
generally motor is switched on with normal voltage and Ra is very small, the Ia at start is very high.This will blow out the fuses and may cause permanent mechanical damage to the motor.To limit this starting current to a safe value a variable resistance is connected in series with armature.This resistance is called as starter.
The voltage equation of dc motor is
V = Eb + IaRa
at start Eb = 0, V= IaRa
Ia = V / Ra. (Ra alone limits the Ia)
generally motor is switched on with normal voltage and Ra is very small, the Ia at start is very high.This will blow out the fuses and may cause permanent mechanical damage to the motor.To limit this starting current to a safe value a variable resistance is connected in series with armature.This resistance is called as starter.
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