Hi,
I'd to get some more information on the torque/speed characteristic of a dc motor that is being used as a generator.
i know that torque is >0 and decreases linearly as speed is increased (positively) in a motor. in the generator mode, is it the torque or the voltage that will be negative? is there such a plot of torque speed that has all 4 Cartesian quadrants to show this?
I'm asking this because in a lab experiment, i found that when i supply a rectified ac voltage to the dc machine, it is motoring and spins clockwise. however, when in apply some positive dc source (to the load) the direction of the spinning is now counterclockwise. So I suppose where i am confused is, since the speed is now negative, does this indicate that we are in the generating mode? I'm not certain since I thought it would be possible to get this rotation by just switching the leads (reversing the polarity) of the input supply.
tia
I'd to get some more information on the torque/speed characteristic of a dc motor that is being used as a generator.
i know that torque is >0 and decreases linearly as speed is increased (positively) in a motor. in the generator mode, is it the torque or the voltage that will be negative? is there such a plot of torque speed that has all 4 Cartesian quadrants to show this?
I'm asking this because in a lab experiment, i found that when i supply a rectified ac voltage to the dc machine, it is motoring and spins clockwise. however, when in apply some positive dc source (to the load) the direction of the spinning is now counterclockwise. So I suppose where i am confused is, since the speed is now negative, does this indicate that we are in the generating mode? I'm not certain since I thought it would be possible to get this rotation by just switching the leads (reversing the polarity) of the input supply.
tia