We’re rewarding the question askers & reputations are being recalculated! Read more.
5 replaced http://robotics.stackexchange.com/ with https://robotics.stackexchange.com/
source | link

1: Under normal conditions, i.e. the motor isn't being asked go from max speed in one direction to max speed in the othergo from max speed in one direction to max speed in the other.
2: This assumes the motor is not being driven by external forcesdriven by external forces.

Note however, as DrFriedParts explainsDrFriedParts explains, this is only part of the story. The maximum continuous stall torque may be much lower than the maximum torque and thus current. For instance if you switch from full torque in one direction to full torque in the other. In this case, the current drawn could be double the continuous stall current. Do this often enough, exceeding the duty cycle of the motor and you could burn out your motor.

Again however, as DrFriedParts explainsDrFriedParts explains, this is also only part of the story. If the motor is being driven by an external force (effectively a -ve load), and thus the motor is turned into a generator, the current drawn may be cancelled out by the current generated by the external force.

1: Under normal conditions, i.e. the motor isn't being asked go from max speed in one direction to max speed in the other.
2: This assumes the motor is not being driven by external forces.

Note however, as DrFriedParts explains, this is only part of the story. The maximum continuous stall torque may be much lower than the maximum torque and thus current. For instance if you switch from full torque in one direction to full torque in the other. In this case, the current drawn could be double the continuous stall current. Do this often enough, exceeding the duty cycle of the motor and you could burn out your motor.

Again however, as DrFriedParts explains, this is also only part of the story. If the motor is being driven by an external force (effectively a -ve load), and thus the motor is turned into a generator, the current drawn may be cancelled out by the current generated by the external force.

1: Under normal conditions, i.e. the motor isn't being asked go from max speed in one direction to max speed in the other.
2: This assumes the motor is not being driven by external forces.

Note however, as DrFriedParts explains, this is only part of the story. The maximum continuous stall torque may be much lower than the maximum torque and thus current. For instance if you switch from full torque in one direction to full torque in the other. In this case, the current drawn could be double the continuous stall current. Do this often enough, exceeding the duty cycle of the motor and you could burn out your motor.

Again however, as DrFriedParts explains, this is also only part of the story. If the motor is being driven by an external force (effectively a -ve load), and thus the motor is turned into a generator, the current drawn may be cancelled out by the current generated by the external force.

4 added 25 characters in body
source | link

1: Under normal conditions, i.e. the motor isn't being asked goinggo from max speed in one direction to max speed in the other.
2: This assumes the motor is not being driven by external forces.

1: Under normal conditions, i.e. going from max speed in one direction to max speed in the other.
2: This assumes the motor is not being driven by external forces.

1: Under normal conditions, i.e. the motor isn't being asked go from max speed in one direction to max speed in the other.
2: This assumes the motor is not being driven by external forces.

3 Added in some notes given DrFriedParts' answer.
source | link

Short answer

Short answer

  • Stall current is the maximum current drawn1, when the motor is applying its maximum torque, either because it is being prevented from moving entirely or because it can no longer accelerate given the load it is under.

  • Free current is the current drawn when the motor is rotating freely, at maximum speed, under no load2 other than friction and back-emf forces in the motor itself.

1: Under normal conditions, i.e. going from max speed in one direction to max speed in the other.
2: This assumes the motor is not being driven by external forces.

Long answer

Long answerStall Current

Note however, as DrFriedParts explains, this is only part of the story. The maximum continuous stall torque may be much lower than the maximum torque and thus current. For instance if you switch from full torque in one direction to full torque in the other. In this case, the current drawn could be double the continuous stall current. Do this often enough, exceeding the duty cycle of the motor and you could burn out your motor.

Free Current

So when running freely, without load, it will rapidly accelerate up to 100 rpm, where it will draw just 180 mA to maintain that speed given friction and back-emf.

Again however, as DrFriedParts explains, this is also only part of the story. If the motor is being driven by an external force (effectively a -ve load), and thus the motor is turned into a generator, the current drawn may be cancelled out by the current generated by the external force.

Short answer

  • Stall current is the maximum current drawn when the motor is applying its maximum torque, either because it is being prevented from moving entirely or because it can no longer accelerate given the load it is under.

  • Free current is the current drawn when the motor is rotating freely, at maximum speed, under no load other than friction and back-emf forces in the motor itself.

Long answer

So when running freely, without load, it will rapidly accelerate up to 100 rpm, where it will draw just 180 mA to maintain that speed given friction and back-emf.

Short answer

  • Stall current is the maximum current drawn1, when the motor is applying its maximum torque, either because it is being prevented from moving entirely or because it can no longer accelerate given the load it is under.

  • Free current is the current drawn when the motor is rotating freely at maximum speed, under no load2 other than friction and back-emf forces in the motor itself.

1: Under normal conditions, i.e. going from max speed in one direction to max speed in the other.
2: This assumes the motor is not being driven by external forces.

Long answer

Stall Current

Note however, as DrFriedParts explains, this is only part of the story. The maximum continuous stall torque may be much lower than the maximum torque and thus current. For instance if you switch from full torque in one direction to full torque in the other. In this case, the current drawn could be double the continuous stall current. Do this often enough, exceeding the duty cycle of the motor and you could burn out your motor.

Free Current

So when running freely, without load, it will rapidly accelerate up to 100 rpm, where it will draw just 180 mA to maintain that speed given friction and back-emf.

Again however, as DrFriedParts explains, this is also only part of the story. If the motor is being driven by an external force (effectively a -ve load), and thus the motor is turned into a generator, the current drawn may be cancelled out by the current generated by the external force.

2 added 434 characters in body
source | link
1
source | link