The direction of rotation of an electric motor will depend on the direction of the magnetic field and the direction of current in the armature. If the direction of the field or current is reversed, the motor rotation will also be inverted. However, if both are reversed at the same time, the motor will continue to rotate in the same direction.
The speed of an engine is given by the number of revolutions of the shaft with respect to time and is expressed in units of revolutions per minute (RPM). A decrease in the magnetic field of the motor causes an increase in its speed and an increase in the field will cause a decrease in the speed of the motor D83075 OLP. The torque developed by a motor to move a given load depends on the current intensity that the armature requests from the power supply. The higher the load, the higher the torque and consequently the higher the current. If the load is lower, the torque will be lower and the current intensity as well. To achieve a higher torque, the motor must rotate at a slower speed, so the speed of a DC motor depends on the load coupled to the shaft.