# Generator Phase

Discussion in 'General Electronics Chat' started by daveuk, Jun 14, 2010.

1. ### daveuk Thread Starter New Member

Jun 14, 2010
1
0
Dear all,

I wonder if someone could assist me with a question which I cannot quite seem to find an answer to on this site, or elsewhere.

If we have an AC generator, in this case a single phase with permanent magnet rotor. Let us now place a purely reactive load, say a capacitor on the output. Obviously there is a phase shift between V and I.

My question is, which one, V or I moves in relation to the position of the rotor itself? So if we have a purely resistive load, and we measure the position in space of the rotor at the moment of the voltage peak.

If we now introduce a phase shift, one of V or I must remain in the same phase as the magnet rotor itself and the other shifts.

Since a voltage is impressed upon the windings, I assume that I moves relative to the rotor itself? However having placed a hall ic near the rotor and connecting different loads and looking at the hall ic output, the voltage and the current on a multichannel scope, it is always the current which remains in phase with the rotor and the voltage which moves, but this seems wrong to me!

Any clarification would be greatly appreciated!

Best regards,

Dave.

2. ### BillB3857 AAC Fanatic!

Feb 28, 2009
2,420
354
My immediate thought is that a magnet moving past a coil produces current in the coil therefore current should always stay constant with the rotation of the magnets. Voltage is the result of current acting upon the external component. My thoughts only and could be very wrong. If so, I'm hopeful that more knowledgeable folks will respond. Inquiring minds want to know!