DC Motors 21–1 DC MACHINES—MOTOR OR GENERATOR? The brief introduction to motors provided by Chapter 20 points to great similarities between motors and generators. Certainly their physical design features are so similar that often it is impossible, without close inspection, to tell a motor from a generator. In fact, there are a few machines that […]
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Direct current fundamentals
Dc motors: dc machines—motor or generator?, the counter-emf in a motorand armature windings
DC Motors 21–1 DC MACHINES—MOTOR OR GENERATOR? The brief introduction to motors provided by Chapter 20 points to great similarities between motors and generators. Certainly their physical design features are so similar that often it is impossible, without close inspection, to tell a motor from a generator. In fact, there are a few machines that […]
Continue reading…
Mechanical motion from electrical energy : the need for added armature coils, from torque to horsepower and summary of mechanical motion from electrical energy.
20–4 THE NEED FOR ADDED ARMATURE COILS This impractical single-coil armature has a variety of faults, one of which is the irregularity of the torque that it produces. When the loop is horizontal, the force on the wire is at its greatest; when the loop is vertical, there is no force on the wire. This […]
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Mechanical motion from electrical energy : the need for added armature coils, from torque to horsepower and summary of mechanical motion from electrical energy.
20–4 THE NEED FOR ADDED ARMATURE COILS This impractical single-coil armature has a variety of faults, one of which is the irregularity of the torque that it produces. When the loop is horizontal, the force on the wire is at its greatest; when the loop is vertical, there is no force on the wire. This […]
Continue reading…
Mechanical motion from electrical energy : basic motor action, torque and rotary motion and the need for commutation
Mechanical Motion from Electrical Energy 20–1 BASIC MOTOR ACTION The term motor action was described briefly in Section 16–4. The sketch accompanying this explanation is reproduced for your convenience as Figure 20–1. Figure 20–1 illustrates that a wire carrying electrons across a magnetic field will be pushed sideways. The current in the wire has a […]
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Mechanical motion from electrical energy : basic motor action, torque and rotary motion and the need for commutation
Mechanical Motion from Electrical Energy 20–1 BASIC MOTOR ACTION The term motor action was described briefly in Section 16–4. The sketch accompanying this explanation is reproduced for your convenience as Figure 20–1. Figure 20–1 illustrates that a wire carrying electrons across a magnetic field will be pushed sideways. The current in the wire has a […]
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Dc generators : power losses, generator data and ratings, magnetohydrodynamic (mhd) generation and summary of dc generators .
19–9 POWER LOSSES All machines suffer power losses in the form of heat. Electrical machines, in particu- lar, suffer two kinds of power losses: copper losses (also known as I2R losses) and stray power losses; see Figure 19–36. This phenomenon is sometimes explained by comparing the machine to a leaky water pipe, with one end […]
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Dc generators : power losses, generator data and ratings, magnetohydrodynamic (mhd) generation and summary of dc generators .
19–9 POWER LOSSES All machines suffer power losses in the form of heat. Electrical machines, in particu- lar, suffer two kinds of power losses: copper losses (also known as I2R losses) and stray power losses; see Figure 19–36. This phenomenon is sometimes explained by comparing the machine to a leaky water pipe, with one end […]
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Dc generators : three types of self-excited generators (series, shunt, and compound), separately excited generators and generator calculations .
19–6 THREE TYPES OF SELF-EXCITED GENERATORS (SERIES, SHUNT, AND COMPOUND) The Series Generator Look back at Figure 19–19 and recall that the field of the series generator carries the entire load current to the external circuit; therefore, the greater the load current, the greater the magnetic field strength; see Figure 19–27. If the generator is […]
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Dc generators : three types of self-excited generators (series, shunt, and compound), separately excited generators and generator calculations .
19–6 THREE TYPES OF SELF-EXCITED GENERATORS (SERIES, SHUNT, AND COMPOUND) The Series Generator Look back at Figure 19–19 and recall that the field of the series generator carries the entire load current to the external circuit; therefore, the greater the load current, the greater the magnetic field strength; see Figure 19–27. If the generator is […]
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