Search results
Results From The WOW.Com Content Network
Because a motor or generator operates most efficiently with the rotor field at right angles to the stator field, it is necessary to either retard or advance the brush position to put the rotor's field into the correct position to be at a right angle to the distorted field. These field effects are reversed when the direction of spin is reversed.
Electromagnetic rotation experiment of Faraday, ca. 1821 [2] Working principle of a homopolar motor: due to movement of negative charges from center towards rim of the disk, a Lorentz force F L is created which brings the entire disk into rotation. The homopolar motor was the first electrical motor to be built.
Fleming's left-hand rule. Fleming's left-hand rule for electric motors is one of a pair of visual mnemonics, the other being Fleming's right-hand rule for generators. [1] [2] [3] They were originated by John Ambrose Fleming, in the late 19th century, as a simple way of working out the direction of motion in an electric motor, or the direction of electric current in an electric generator.
In motor-generators, reverse current relays prevent the battery from discharging and motorizing the generator. Since D.C. motor field loss can cause a hazardous runaway or overspeed condition, loss of field relays [25] are connected in parallel with the motor's field to sense field current. When the field current decreases below a set point ...
A motor controller is a device or group of devices that can coordinate in a predetermined manner the performance of an electric motor. [1] A motor controller might include a manual or automatic means for starting and stopping the motor, selecting forward or reverse rotation, selecting and regulating the speed, regulating or limiting the torque, and protecting against overloads and electrical ...
By connecting its terminals, the motor's kinetic energy is consumed rapidly in form of electrical current and causes the motor to slow down. Another case allows the motor to coast to a stop, as the motor is effectively disconnected from the circuit. The following table summarizes operation, with S1-S4 corresponding to the diagram above.
Reversing (also known as backing up) is the process of driving a vehicle in the reverse direction in order to maneuver. Rear view mirrors are somewhat standard equipment for this endeavor. Reversing a vehicle is used as an intermediate step to complete a three point turn , J-turn , parallel park , or similar maneuver.
The motor constant is winding independent (as long as the same conductive material is used for wires); e.g., winding a motor with 6 turns with 2 parallel wires instead of 12 turns single wire will double the velocity constant, , but remains unchanged.