Direct current

 

Direct current - current flowing in one direction only. 

Constant - Doesn't vary with time

Uniform - doesnt vary with distance. 

The circular motion of an alternator fives an outut which is a sine wave

 

we have 3 seperate coils each producing A.C, But the coild are at 120o from each other 

We can only use delta if the loads are exactly balanced, otherwise we must use star,

 in delta there is no neutral

At any time the 3 voltages add up to zero and ir R1=R2=R3 then the 3 currents will add 

up to zero

The neutral carries the balances current.