id stringlengths 24 24 | question stringlengths 1 270 | answer stringlengths 1 239 | documents listlengths 1 1 |
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5726b1f0f1498d1400e8e7b6 | What is the result of using AC power on a DC motor? | efficiency losses | [
"Electric_motor\n\nOperating at normal power line frequencies, universal motors are often found in a range less than 1000 watts. Universal motors also formed the basis of the traditional railway traction motor in electric railways. In this application, the use of AC to power a motor originally designed to run on DC... |
5726b1f0f1498d1400e8e7b7 | What were universal motor pole pieces constructed from? | solid (un-laminated) iron | [
"Electric_motor\n\nOperating at normal power line frequencies, universal motors are often found in a range less than 1000 watts. Universal motors also formed the basis of the traditional railway traction motor in electric railways. In this application, the use of AC to power a motor originally designed to run on DC... |
5726b408dd62a815002e8d66 | What kind of motor can employ both AC and DC? | universal | [
"Electric_motor\n\nAn advantage of the universal motor is that AC supplies may be used on motors which have some characteristics more common in DC motors, specifically high starting torque and very compact design if high running speeds are used. The negative aspect is the maintenance and short life problems caused ... |
5726b408dd62a815002e8d67 | What component of a universal motor is most likely to fail? | commutator | [
"Electric_motor\n\nAn advantage of the universal motor is that AC supplies may be used on motors which have some characteristics more common in DC motors, specifically high starting torque and very compact design if high running speeds are used. The negative aspect is the maintenance and short life problems caused ... |
5726b408dd62a815002e8d68 | When is torque most important in universal motor applications? | starting | [
"Electric_motor\n\nAn advantage of the universal motor is that AC supplies may be used on motors which have some characteristics more common in DC motors, specifically high starting torque and very compact design if high running speeds are used. The negative aspect is the maintenance and short life problems caused ... |
5726b408dd62a815002e8d69 | Switching the field winding in washing machines causes the drum to agitate how? | forwards and in reverse | [
"Electric_motor\n\nAn advantage of the universal motor is that AC supplies may be used on motors which have some characteristics more common in DC motors, specifically high starting torque and very compact design if high running speeds are used. The negative aspect is the maintenance and short life problems caused ... |
5726b408dd62a815002e8d6a | How is stepped speed control achieved? | Multiple taps on the field coil provide | [
"Electric_motor\n\nAn advantage of the universal motor is that AC supplies may be used on motors which have some characteristics more common in DC motors, specifically high starting torque and very compact design if high running speeds are used. The negative aspect is the maintenance and short life problems caused ... |
5726b4e8f1498d1400e8e83c | At around what RMP do weed trimmer motors operate? | 10,000 | [
"Electric_motor\n\nWhereas SCIMs cannot turn a shaft faster than allowed by the power line frequency, universal motors can run at much higher speeds. This makes them useful for appliances such as blenders, vacuum cleaners, and hair dryers where high speed and light weight are desirable. They are also commonly used ... |
5726b4e8f1498d1400e8e83d | At around what RMP do miniature grinders operate? | 30,000 | [
"Electric_motor\n\nWhereas SCIMs cannot turn a shaft faster than allowed by the power line frequency, universal motors can run at much higher speeds. This makes them useful for appliances such as blenders, vacuum cleaners, and hair dryers where high speed and light weight are desirable. They are also commonly used ... |
5726b4e8f1498d1400e8e83e | What type of motor can universal motors operate much faster than? | SCIMs | [
"Electric_motor\n\nWhereas SCIMs cannot turn a shaft faster than allowed by the power line frequency, universal motors can run at much higher speeds. This makes them useful for appliances such as blenders, vacuum cleaners, and hair dryers where high speed and light weight are desirable. They are also commonly used ... |
5726b4e8f1498d1400e8e83f | What attributes make universal motors desireable for consumer applications like hair dryers? | high speed and light weight | [
"Electric_motor\n\nWhereas SCIMs cannot turn a shaft faster than allowed by the power line frequency, universal motors can run at much higher speeds. This makes them useful for appliances such as blenders, vacuum cleaners, and hair dryers where high speed and light weight are desirable. They are also commonly used ... |
5726b5dcf1498d1400e8e868 | What determines the properties of speed and torque? | shape of the rotor bars | [
"Electric_motor\n\nCurrents induced into this winding provide the rotor magnetic field. The shape of the rotor bars determines the speed-torque characteristics. At low speeds, the current induced in the squirrel cage is nearly at line frequency and tends to be in the outer parts of the rotor cage. As the motor acce... |
5726b5dcf1498d1400e8e869 | At high speed, where is the most current? | interior of the winding | [
"Electric_motor\n\nCurrents induced into this winding provide the rotor magnetic field. The shape of the rotor bars determines the speed-torque characteristics. At low speeds, the current induced in the squirrel cage is nearly at line frequency and tends to be in the outer parts of the rotor cage. As the motor acce... |
5726b5dcf1498d1400e8e86a | Is the current frequency higher or lower at high speed? | lower | [
"Electric_motor\n\nCurrents induced into this winding provide the rotor magnetic field. The shape of the rotor bars determines the speed-torque characteristics. At low speeds, the current induced in the squirrel cage is nearly at line frequency and tends to be in the outer parts of the rotor cage. As the motor acce... |
5726b5dcf1498d1400e8e86b | Changing the shapes of the bars creates what? | variable resistance | [
"Electric_motor\n\nCurrents induced into this winding provide the rotor magnetic field. The shape of the rotor bars determines the speed-torque characteristics. At low speeds, the current induced in the squirrel cage is nearly at line frequency and tends to be in the outer parts of the rotor cage. As the motor acce... |
5726b5dcf1498d1400e8e86c | Where can variable resistance be created? | rotor circuit | [
"Electric_motor\n\nCurrents induced into this winding provide the rotor magnetic field. The shape of the rotor bars determines the speed-torque characteristics. At low speeds, the current induced in the squirrel cage is nearly at line frequency and tends to be in the outer parts of the rotor cage. As the motor acce... |
5726b6a15951b619008f7b91 | Where might a resistor be attached? | rotor circuit | [
"Electric_motor\n\nIn a WRIM, the rotor winding is made of many turns of insulated wire and is connected to slip rings on the motor shaft. An external resistor or other control devices can be connected in the rotor circuit. Resistors allow control of the motor speed, although significant power is dissipated in the ... |
5726b6a15951b619008f7b92 | What can a resistor control? | motor speed | [
"Electric_motor\n\nIn a WRIM, the rotor winding is made of many turns of insulated wire and is connected to slip rings on the motor shaft. An external resistor or other control devices can be connected in the rotor circuit. Resistors allow control of the motor speed, although significant power is dissipated in the ... |
5726b6a15951b619008f7b93 | How might wasted power be salvaged? | inverter or separate motor-generator | [
"Electric_motor\n\nIn a WRIM, the rotor winding is made of many turns of insulated wire and is connected to slip rings on the motor shaft. An external resistor or other control devices can be connected in the rotor circuit. Resistors allow control of the motor speed, although significant power is dissipated in the ... |
5726b6a15951b619008f7b94 | From where may a converter be fed? | rotor circuit | [
"Electric_motor\n\nIn a WRIM, the rotor winding is made of many turns of insulated wire and is connected to slip rings on the motor shaft. An external resistor or other control devices can be connected in the rotor circuit. Resistors allow control of the motor speed, although significant power is dissipated in the ... |
5726b731dd62a815002e8dc8 | What will a motor do if the load is reduced? | speed up | [
"Electric_motor\n\nWhen used with a load that has a torque curve that increases with speed, the motor will operate at the speed where the torque developed by the motor is equal to the load torque. Reducing the load will cause the motor to speed up, and increasing the load will cause the motor to slow down until the... |
5726b731dd62a815002e8dc9 | What will a motor do if the load is increased? | slow down | [
"Electric_motor\n\nWhen used with a load that has a torque curve that increases with speed, the motor will operate at the speed where the torque developed by the motor is equal to the load torque. Reducing the load will cause the motor to speed up, and increasing the load will cause the motor to slow down until the... |
5726b731dd62a815002e8dca | Where are slip losses dissipated? | secondary resistors | [
"Electric_motor\n\nWhen used with a load that has a torque curve that increases with speed, the motor will operate at the speed where the torque developed by the motor is equal to the load torque. Reducing the load will cause the motor to speed up, and increasing the load will cause the motor to slow down until the... |
5726b731dd62a815002e8dcb | How efficient is such a design? | very poor | [
"Electric_motor\n\nWhen used with a load that has a torque curve that increases with speed, the motor will operate at the speed where the torque developed by the motor is equal to the load torque. Reducing the load will cause the motor to speed up, and increasing the load will cause the motor to slow down until the... |
5726b7fadd62a815002e8dfc | How are torque motors used in computer gaming? | feedback steering wheels | [
"Electric_motor\n\nA common application of a torque motor would be the supply- and take-up reel motors in a tape drive. In this application, driven from a low voltage, the characteristics of these motors allow a relatively constant light tension to be applied to the tape whether or not the capstan is feeding tape p... |
5726b7fadd62a815002e8dfd | A torque motor at low voltage provides what? | constant light tension | [
"Electric_motor\n\nA common application of a torque motor would be the supply- and take-up reel motors in a tape drive. In this application, driven from a low voltage, the characteristics of these motors allow a relatively constant light tension to be applied to the tape whether or not the capstan is feeding tape p... |
5726b7fadd62a815002e8dfe | A torque motor at high voltage provides what? | higher torque | [
"Electric_motor\n\nA common application of a torque motor would be the supply- and take-up reel motors in a tape drive. In this application, driven from a low voltage, the characteristics of these motors allow a relatively constant light tension to be applied to the tape whether or not the capstan is feeding tape p... |
5726b7fadd62a815002e8dff | In a tape drive, what is not needed if a torque motor is used? | gears or clutches | [
"Electric_motor\n\nA common application of a torque motor would be the supply- and take-up reel motors in a tape drive. In this application, driven from a low voltage, the characteristics of these motors allow a relatively constant light tension to be applied to the tape whether or not the capstan is feeding tape p... |
5726b8c9708984140094cf1f | What element of a combustion engine does a governor monitor? | electrical pulses | [
"Electric_motor\n\nAnother common application is the control of the throttle of an internal combustion engine in conjunction with an electronic governor. In this usage, the motor works against a return spring to move the throttle in accordance with the output of the governor. The latter monitors engine speed by cou... |
5726b8c9708984140094cf20 | What is a governor connected to? | return spring | [
"Electric_motor\n\nAnother common application is the control of the throttle of an internal combustion engine in conjunction with an electronic governor. In this usage, the motor works against a return spring to move the throttle in accordance with the output of the governor. The latter monitors engine speed by cou... |
5726b8c9708984140094cf21 | What kinds of adjustments would a governor make? | small | [
"Electric_motor\n\nAnother common application is the control of the throttle of an internal combustion engine in conjunction with an electronic governor. In this usage, the motor works against a return spring to move the throttle in accordance with the output of the governor. The latter monitors engine speed by cou... |
5726b8c9708984140094cf22 | What would a governor do to a too-fast running engine? | reduce the current being applied to the motor | [
"Electric_motor\n\nAnother common application is the control of the throttle of an internal combustion engine in conjunction with an electronic governor. In this usage, the motor works against a return spring to move the throttle in accordance with the output of the governor. The latter monitors engine speed by cou... |
5726b9d3dd62a815002e8e44 | How much slip does a synchronous motor have? | zero | [
"Electric_motor\n\nA synchronous electric motor is an AC motor distinguished by a rotor spinning with coils passing magnets at the same rate as the AC and resulting magnetic field which drives it. Another way of saying this is that it has zero slip under usual operating conditions. Contrast this with an induction m... |
5726b9d3dd62a815002e8e45 | How does an induction motor produce torque? | slip | [
"Electric_motor\n\nA synchronous electric motor is an AC motor distinguished by a rotor spinning with coils passing magnets at the same rate as the AC and resulting magnetic field which drives it. Another way of saying this is that it has zero slip under usual operating conditions. Contrast this with an induction m... |
5726b9d3dd62a815002e8e46 | Whithout rotor windings, how must a Hammond clock be started? | manually | [
"Electric_motor\n\nA synchronous electric motor is an AC motor distinguished by a rotor spinning with coils passing magnets at the same rate as the AC and resulting magnetic field which drives it. Another way of saying this is that it has zero slip under usual operating conditions. Contrast this with an induction m... |
5726b9d3dd62a815002e8e47 | How can a synchronous motor be made more like an induction motor? | DC field | [
"Electric_motor\n\nA synchronous electric motor is an AC motor distinguished by a rotor spinning with coils passing magnets at the same rate as the AC and resulting magnetic field which drives it. Another way of saying this is that it has zero slip under usual operating conditions. Contrast this with an induction m... |
5726b9d3dd62a815002e8e48 | How is current brought to the rotor in a synchronous motor? | Slip rings and brushes | [
"Electric_motor\n\nA synchronous electric motor is an AC motor distinguished by a rotor spinning with coils passing magnets at the same rate as the AC and resulting magnetic field which drives it. Another way of saying this is that it has zero slip under usual operating conditions. Contrast this with an induction m... |
5726bcf3f1498d1400e8e9a6 | What do hysteresis synchronous motors' rotors do when slip rate decreases? | becomes temporarily magnetized | [
"Electric_motor\n\nFinally, hysteresis synchronous motors typically are (essentially) two-phase motors with a phase-shifting capacitor for one phase. They start like induction motors, but when slip rate decreases sufficiently, the rotor (a smooth cylinder) becomes temporarily magnetized. Its distributed poles make ... |
5726bcf3f1498d1400e8e9a7 | When in operation, what do hysteresis synchronous motors poles do? | stay in place | [
"Electric_motor\n\nFinally, hysteresis synchronous motors typically are (essentially) two-phase motors with a phase-shifting capacitor for one phase. They start like induction motors, but when slip rate decreases sufficiently, the rotor (a smooth cylinder) becomes temporarily magnetized. Its distributed poles make ... |
5726bcf3f1498d1400e8e9a8 | What do hysteresis synchronous motors resemble at startup? | induction motors | [
"Electric_motor\n\nFinally, hysteresis synchronous motors typically are (essentially) two-phase motors with a phase-shifting capacitor for one phase. They start like induction motors, but when slip rate decreases sufficiently, the rotor (a smooth cylinder) becomes temporarily magnetized. Its distributed poles make ... |
5726bcf3f1498d1400e8e9a9 | How can a hysteresis synchronous motor's rotor be described? | a smooth cylinder | [
"Electric_motor\n\nFinally, hysteresis synchronous motors typically are (essentially) two-phase motors with a phase-shifting capacitor for one phase. They start like induction motors, but when slip rate decreases sufficiently, the rotor (a smooth cylinder) becomes temporarily magnetized. Its distributed poles make ... |
5726bcf3f1498d1400e8e9aa | What do the distributed poles of a hysteresis synchronous motor resemble? | PMSM | [
"Electric_motor\n\nFinally, hysteresis synchronous motors typically are (essentially) two-phase motors with a phase-shifting capacitor for one phase. They start like induction motors, but when slip rate decreases sufficiently, the rotor (a smooth cylinder) becomes temporarily magnetized. Its distributed poles make ... |
5726be1add62a815002e8f10 | What type of motor has two independent multiphase winding sets? | Doubly fed electric motors | [
"Electric_motor\n\nDoubly fed electric motors have two independent multiphase winding sets, which contribute active (i.e., working) power to the energy conversion process, with at least one of the winding sets electronically controlled for variable speed operation. Two independent multiphase winding sets (i.e., dua... |
5726be1add62a815002e8f11 | What advanage do independent multiphase winding sets have? | contribute active (i.e., working) power to the energy conversion process | [
"Electric_motor\n\nDoubly fed electric motors have two independent multiphase winding sets, which contribute active (i.e., working) power to the energy conversion process, with at least one of the winding sets electronically controlled for variable speed operation. Two independent multiphase winding sets (i.e., dua... |
5726be1add62a815002e8f12 | What is one of the independent multiphase winding sets configured for? | variable speed operation | [
"Electric_motor\n\nDoubly fed electric motors have two independent multiphase winding sets, which contribute active (i.e., working) power to the energy conversion process, with at least one of the winding sets electronically controlled for variable speed operation. Two independent multiphase winding sets (i.e., dua... |
5726be1add62a815002e8f13 | Doubly fed motors have what advantage over single fed? | twice the constant torque speed range | [
"Electric_motor\n\nDoubly fed electric motors have two independent multiphase winding sets, which contribute active (i.e., working) power to the energy conversion process, with at least one of the winding sets electronically controlled for variable speed operation. Two independent multiphase winding sets (i.e., dua... |
5726bec2dd62a815002e8f36 | A coreless DC motor is distinguished by what? | rapid acceleration | [
"Electric_motor\n\nNothing in the principle of any of the motors described above requires that the iron (steel) portions of the rotor actually rotate. If the soft magnetic material of the rotor is made in the form of a cylinder, then (except for the effect of hysteresis) torque is exerted only on the windings of th... |
5726bec2dd62a815002e8f37 | What is absent in a coreless DC motor? | iron core | [
"Electric_motor\n\nNothing in the principle of any of the motors described above requires that the iron (steel) portions of the rotor actually rotate. If the soft magnetic material of the rotor is made in the form of a cylinder, then (except for the effect of hysteresis) torque is exerted only on the windings of th... |
5726bec2dd62a815002e8f38 | What forms can the rotor take? | winding-filled cylinder, or a self-supporting structure | [
"Electric_motor\n\nNothing in the principle of any of the motors described above requires that the iron (steel) portions of the rotor actually rotate. If the soft magnetic material of the rotor is made in the form of a cylinder, then (except for the effect of hysteresis) torque is exerted only on the windings of th... |
5726bfb05951b619008f7d23 | What is a likely problem of coreless DC motors? | Overheating | [
"Electric_motor\n\nBecause the rotor is much lighter in weight (mass) than a conventional rotor formed from copper windings on steel laminations, the rotor can accelerate much more rapidly, often achieving a mechanical time constant under one ms. This is especially true if the windings use aluminum rather than the ... |
5726bfb05951b619008f7d24 | How does a coreless rotor compare to traditional rotors in terms of weight? | lighter | [
"Electric_motor\n\nBecause the rotor is much lighter in weight (mass) than a conventional rotor formed from copper windings on steel laminations, the rotor can accelerate much more rapidly, often achieving a mechanical time constant under one ms. This is especially true if the windings use aluminum rather than the ... |
5726bfb05951b619008f7d25 | What advantage does a coreless rotor have over traditional variants? | accelerate much more rapidly | [
"Electric_motor\n\nBecause the rotor is much lighter in weight (mass) than a conventional rotor formed from copper windings on steel laminations, the rotor can accelerate much more rapidly, often achieving a mechanical time constant under one ms. This is especially true if the windings use aluminum rather than the ... |
5726bfb05951b619008f7d26 | How is a coreless motor cooled? | forced air | [
"Electric_motor\n\nBecause the rotor is much lighter in weight (mass) than a conventional rotor formed from copper windings on steel laminations, the rotor can accelerate much more rapidly, often achieving a mechanical time constant under one ms. This is especially true if the windings use aluminum rather than the ... |
5726bfb05951b619008f7d27 | The lack of a metal mass in the core causes what function to be absent? | heat sink | [
"Electric_motor\n\nBecause the rotor is much lighter in weight (mass) than a conventional rotor formed from copper windings on steel laminations, the rotor can accelerate much more rapidly, often achieving a mechanical time constant under one ms. This is especially true if the windings use aluminum rather than the ... |
5726c077708984140094d07d | What was the original purpose for pancake motors? | drive the capstan(s) of magnetic tape drives | [
"Electric_motor\n\nThese motors were originally invented to drive the capstan(s) of magnetic tape drives in the burgeoning computer industry, where minimal time to reach operating speed and minimal stopping distance were critical. Pancake motors are still widely used in high-performance servo-controlled systems, ro... |
5726c077708984140094d07e | What are advantages of pancake motors? | minimal time to reach operating speed and minimal stopping distance | [
"Electric_motor\n\nThese motors were originally invented to drive the capstan(s) of magnetic tape drives in the burgeoning computer industry, where minimal time to reach operating speed and minimal stopping distance were critical. Pancake motors are still widely used in high-performance servo-controlled systems, ro... |
5726c077708984140094d07f | For what type of military applications are pancake motors currently used? | high temperature | [
"Electric_motor\n\nThese motors were originally invented to drive the capstan(s) of magnetic tape drives in the burgeoning computer industry, where minimal time to reach operating speed and minimal stopping distance were critical. Pancake motors are still widely used in high-performance servo-controlled systems, ro... |
5726c077708984140094d080 | What type of servo-controlled systems use pancake motors? | high-performance | [
"Electric_motor\n\nThese motors were originally invented to drive the capstan(s) of magnetic tape drives in the burgeoning computer industry, where minimal time to reach operating speed and minimal stopping distance were critical. Pancake motors are still widely used in high-performance servo-controlled systems, ro... |
5726c204708984140094d0ab | What may servo motors be used for? | machine tools, pen plotters, and other process systems | [
"Electric_motor\n\nA servomotor is a motor, very often sold as a complete module, which is used within a position-control or speed-control feedback control system mainly control valves, such as motor-operated control valves. Servomotors are used in applications such as machine tools, pen plotters, and other process... |
5726c204708984140094d0ac | What must be well understood when applying a servo motor for use? | speed, torque, and power | [
"Electric_motor\n\nA servomotor is a motor, very often sold as a complete module, which is used within a position-control or speed-control feedback control system mainly control valves, such as motor-operated control valves. Servomotors are used in applications such as machine tools, pen plotters, and other process... |
5726c204708984140094d0ad | What factors limit performance of servo motors? | winding inductance and rotor inertia | [
"Electric_motor\n\nA servomotor is a motor, very often sold as a complete module, which is used within a position-control or speed-control feedback control system mainly control valves, such as motor-operated control valves. Servomotors are used in applications such as machine tools, pen plotters, and other process... |
5726c204708984140094d0ae | Large, slow servos can use what types of motors? | conventional AC or DC motors | [
"Electric_motor\n\nA servomotor is a motor, very often sold as a complete module, which is used within a position-control or speed-control feedback control system mainly control valves, such as motor-operated control valves. Servomotors are used in applications such as machine tools, pen plotters, and other process... |
5726c204708984140094d0af | When might coreless motors be used in servo applications? | As dynamic response requirements increase | [
"Electric_motor\n\nA servomotor is a motor, very often sold as a complete module, which is used within a position-control or speed-control feedback control system mainly control valves, such as motor-operated control valves. Servomotors are used in applications such as machine tools, pen plotters, and other process... |
5726c9505951b619008f7e0b | How do servo motors differ from stepper motors? | position feedback is continuous | [
"Electric_motor\n\nA servo system differs from some stepper motor applications in that the position feedback is continuous while the motor is running; a stepper system relies on the motor not to \"miss steps\" for short term accuracy, although a stepper system may include a \"home\" switch or other element to provi... |
5726c9505951b619008f7e0c | How does a stepper system achieve stability? | a "home" switch | [
"Electric_motor\n\nA servo system differs from some stepper motor applications in that the position feedback is continuous while the motor is running; a stepper system relies on the motor not to \"miss steps\" for short term accuracy, although a stepper system may include a \"home\" switch or other element to provi... |
5726c9505951b619008f7e0d | What makes a printer home switch work? | position sensor | [
"Electric_motor\n\nA servo system differs from some stepper motor applications in that the position feedback is continuous while the motor is running; a stepper system relies on the motor not to \"miss steps\" for short term accuracy, although a stepper system may include a \"home\" switch or other element to provi... |
5726c9505951b619008f7e0e | What kind of counter keeps track of a print head's position? | bidirectional | [
"Electric_motor\n\nA servo system differs from some stepper motor applications in that the position feedback is continuous while the motor is running; a stepper system relies on the motor not to \"miss steps\" for short term accuracy, although a stepper system may include a \"home\" switch or other element to provi... |
5726c9505951b619008f7e0f | A stepper system's motor is relied on to not do what? | miss steps | [
"Electric_motor\n\nA servo system differs from some stepper motor applications in that the position feedback is continuous while the motor is running; a stepper system relies on the motor not to \"miss steps\" for short term accuracy, although a stepper system may include a \"home\" switch or other element to provi... |
5726ca94708984140094d179 | When are stepper motors most useful? | when precise rotations are required | [
"Electric_motor\n\nStepper motors are a type of motor frequently used when precise rotations are required. In a stepper motor an internal rotor containing PMs or a magnetically soft rotor with salient poles is controlled by a set of external magnets that are switched electronically. A stepper motor may also be thou... |
5726ca94708984140094d17a | What two devices can describe a stepper motor? | DC electric motor and a rotary solenoid | [
"Electric_motor\n\nStepper motors are a type of motor frequently used when precise rotations are required. In a stepper motor an internal rotor containing PMs or a magnetically soft rotor with salient poles is controlled by a set of external magnets that are switched electronically. A stepper motor may also be thou... |
5726ca94708984140094d17b | What do stepper motor rotors allign themselves with? | magnetic field produced by the energized field winding | [
"Electric_motor\n\nStepper motors are a type of motor frequently used when precise rotations are required. In a stepper motor an internal rotor containing PMs or a magnetically soft rotor with salient poles is controlled by a set of external magnets that are switched electronically. A stepper motor may also be thou... |
5726ca94708984140094d17c | How does a stepper motor differ from a synchronous motor? | the stepper motor may not rotate continuously | [
"Electric_motor\n\nStepper motors are a type of motor frequently used when precise rotations are required. In a stepper motor an internal rotor containing PMs or a magnetically soft rotor with salient poles is controlled by a set of external magnets that are switched electronically. A stepper motor may also be thou... |
5726ca94708984140094d17d | What types of velocities and positions is the stepper motor capable of? | forwards or backwards, and it may change direction, stop, speed up or slow down | [
"Electric_motor\n\nStepper motors are a type of motor frequently used when precise rotations are required. In a stepper motor an internal rotor containing PMs or a magnetically soft rotor with salient poles is controlled by a set of external magnets that are switched electronically. A stepper motor may also be thou... |
5726cb58f1498d1400e8eb78 | What is a trait of a sophisticated stepper motor? | proportionally control the power to the field windings | [
"Electric_motor\n\nSimple stepper motor drivers entirely energize or entirely de-energize the field windings, leading the rotor to \"cog\" to a limited number of positions; more sophisticated drivers can proportionally control the power to the field windings, allowing the rotors to position between the cog points a... |
5726cb58f1498d1400e8eb79 | What does proportinal control of the field windings in a stepper motor achieve? | rotate extremely smoothly | [
"Electric_motor\n\nSimple stepper motor drivers entirely energize or entirely de-energize the field windings, leading the rotor to \"cog\" to a limited number of positions; more sophisticated drivers can proportionally control the power to the field windings, allowing the rotors to position between the cog points a... |
5726cb58f1498d1400e8eb7a | What is another name for smooth rotation? | microstepping | [
"Electric_motor\n\nSimple stepper motor drivers entirely energize or entirely de-energize the field windings, leading the rotor to \"cog\" to a limited number of positions; more sophisticated drivers can proportionally control the power to the field windings, allowing the rotors to position between the cog points a... |
5726cb58f1498d1400e8eb7b | With what other device are stepper motors most versatile? | digital servo-controlled system | [
"Electric_motor\n\nSimple stepper motor drivers entirely energize or entirely de-energize the field windings, leading the rotor to \"cog\" to a limited number of positions; more sophisticated drivers can proportionally control the power to the field windings, allowing the rotors to position between the cog points a... |
5726cc10f1498d1400e8eb80 | Why were stepper motors abandoned in computer drive designs? | precision and speed limitations | [
"Electric_motor\n\nStepper motors can be rotated to a specific angle in discrete steps with ease, and hence stepper motors are used for read/write head positioning in computer floppy diskette drives. They were used for the same purpose in pre-gigabyte era computer disk drives, where the precision and speed they off... |
5726cc10f1498d1400e8eb81 | What do newer computer drives use instead of stepper motors? | voice coil-based head actuator systems | [
"Electric_motor\n\nStepper motors can be rotated to a specific angle in discrete steps with ease, and hence stepper motors are used for read/write head positioning in computer floppy diskette drives. They were used for the same purpose in pre-gigabyte era computer disk drives, where the precision and speed they off... |
5726cc10f1498d1400e8eb82 | In what direction do modern coil actuators move? | perpendicular to the magnetic lines of force | [
"Electric_motor\n\nStepper motors can be rotated to a specific angle in discrete steps with ease, and hence stepper motors are used for read/write head positioning in computer floppy diskette drives. They were used for the same purpose in pre-gigabyte era computer disk drives, where the precision and speed they off... |
5726cc10f1498d1400e8eb83 | To what device does the term, "voice coil" historically refer? | the structure in a typical (cone type) loudspeaker | [
"Electric_motor\n\nStepper motors can be rotated to a specific angle in discrete steps with ease, and hence stepper motors are used for read/write head positioning in computer floppy diskette drives. They were used for the same purpose in pre-gigabyte era computer disk drives, where the precision and speed they off... |
5726cdc15951b619008f7e7d | List two alternatives to rotary stepper motors in printer applications. | linear stepper motors or servomotors | [
"Electric_motor\n\nStepper motors were and still are often used in computer printers, optical scanners, and digital photocopiers to move the optical scanning element, the print head carriage (of dot matrix and inkjet printers), and the platen or feed rollers. Likewise, many computer plotters (which since the early ... |
5726cdc15951b619008f7e7e | In scanners, what do stepper motors move? | optical scanning element | [
"Electric_motor\n\nStepper motors were and still are often used in computer printers, optical scanners, and digital photocopiers to move the optical scanning element, the print head carriage (of dot matrix and inkjet printers), and the platen or feed rollers. Likewise, many computer plotters (which since the early ... |
5726cdc15951b619008f7e7f | In printers and copiers, what do stepper motors move? | print head carriage (of dot matrix and inkjet printers), and the platen or feed rollers | [
"Electric_motor\n\nStepper motors were and still are often used in computer printers, optical scanners, and digital photocopiers to move the optical scanning element, the print head carriage (of dot matrix and inkjet printers), and the platen or feed rollers. Likewise, many computer plotters (which since the early ... |
5726cea6708984140094d1f1 | Voltage opposing the motor supply voltage is called what? | back electromotive force | [
"Electric_motor\n\nSince the armature windings of a direct-current or universal motor are moving through a magnetic field, they have a voltage induced in them. This voltage tends to oppose the motor supply voltage and so is called \"back electromotive force (emf)\". The voltage is proportional to the running speed ... |
5726cea6708984140094d1f2 | EMP is proportional to what? | the running speed of the motor | [
"Electric_motor\n\nSince the armature windings of a direct-current or universal motor are moving through a magnetic field, they have a voltage induced in them. This voltage tends to oppose the motor supply voltage and so is called \"back electromotive force (emf)\". The voltage is proportional to the running speed ... |
5726cea6708984140094d1f3 | Voltage at the brushes is equal to what? | back emf of the motor, plus the voltage drop across the winding internal resistance | [
"Electric_motor\n\nSince the armature windings of a direct-current or universal motor are moving through a magnetic field, they have a voltage induced in them. This voltage tends to oppose the motor supply voltage and so is called \"back electromotive force (emf)\". The voltage is proportional to the running speed ... |
5726cea6708984140094d1f4 | If load increases, what happens to current drawn? | more current is drawn from the supply | [
"Electric_motor\n\nSince the armature windings of a direct-current or universal motor are moving through a magnetic field, they have a voltage induced in them. This voltage tends to oppose the motor supply voltage and so is called \"back electromotive force (emf)\". The voltage is proportional to the running speed ... |
5726cf6d708984140094d201 | What needs to be known to calculate torque? | fields in the air gap | [
"Electric_motor\n\nAll the electromagnetic motors, and that includes the types mentioned here derive the torque from the vector product of the interacting fields. For calculating the torque it is necessary to know the fields in the air gap . Once these have been established by mathematical analysis using FEA or oth... |
5726cf6d708984140094d202 | How are the many calculations to determine torque done? | FEA | [
"Electric_motor\n\nAll the electromagnetic motors, and that includes the types mentioned here derive the torque from the vector product of the interacting fields. For calculating the torque it is necessary to know the fields in the air gap . Once these have been established by mathematical analysis using FEA or oth... |
5726cf6d708984140094d203 | How is torque determined? | from the vector product of the interacting fields | [
"Electric_motor\n\nAll the electromagnetic motors, and that includes the types mentioned here derive the torque from the vector product of the interacting fields. For calculating the torque it is necessary to know the fields in the air gap . Once these have been established by mathematical analysis using FEA or oth... |
5726cf6d708984140094d204 | What is the formulia to determine torque? | the integral of all the vectors of force multiplied by the radius of each vector | [
"Electric_motor\n\nAll the electromagnetic motors, and that includes the types mentioned here derive the torque from the vector product of the interacting fields. For calculating the torque it is necessary to know the fields in the air gap . Once these have been established by mathematical analysis using FEA or oth... |
5726d031f1498d1400e8ec00 | What are factors that determine shaft torque? | torque current), voltage, pole-pair number, excitation frequency (i.e., synchronous speed), and air-gap flux density | [
"Electric_motor\n\nWhen optimally designed within a given core saturation constraint and for a given active current (i.e., torque current), voltage, pole-pair number, excitation frequency (i.e., synchronous speed), and air-gap flux density, all categories of electric motors or generators will exhibit virtually the ... |
5726d031f1498d1400e8ec01 | Whate decides the size of an electromagnetic core? | air-gap area with winding slots and back-iron depth | [
"Electric_motor\n\nWhen optimally designed within a given core saturation constraint and for a given active current (i.e., torque current), voltage, pole-pair number, excitation frequency (i.e., synchronous speed), and air-gap flux density, all categories of electric motors or generators will exhibit virtually the ... |
5726d031f1498d1400e8ec02 | What limits excessive torque? | magnetic core saturation or safe operating temperature rise and voltage | [
"Electric_motor\n\nWhen optimally designed within a given core saturation constraint and for a given active current (i.e., torque current), voltage, pole-pair number, excitation frequency (i.e., synchronous speed), and air-gap flux density, all categories of electric motors or generators will exhibit virtually the ... |
5726d11ddd62a815002e912a | What is the only device with dual ported transformer circuit topology? | brushless wound-rotor | [
"Electric_motor\n\nThe brushless wound-rotor synchronous doubly-fed (BWRSDF) machine is the only electric machine with a truly dual ported transformer circuit topology (i.e., both ports independently excited with no short-circuited port). The dual ported transformer circuit topology is known to be unstable and requ... |
5726d11ddd62a815002e912b | What is a brushless wound-rotor? | both ports independently excited with no short-circuited port | [
"Electric_motor\n\nThe brushless wound-rotor synchronous doubly-fed (BWRSDF) machine is the only electric machine with a truly dual ported transformer circuit topology (i.e., both ports independently excited with no short-circuited port). The dual ported transformer circuit topology is known to be unstable and requ... |
5726d11ddd62a815002e912c | How does a brushless wound rotor achieve stability? | a multiphase slip-ring-brush assembly to propagate limited power to the rotor winding set | [
"Electric_motor\n\nThe brushless wound-rotor synchronous doubly-fed (BWRSDF) machine is the only electric machine with a truly dual ported transformer circuit topology (i.e., both ports independently excited with no short-circuited port). The dual ported transformer circuit topology is known to be unstable and requ... |
5726d11ddd62a815002e912d | What is the theoretical maximum of a brushless wound rotor? | eight times operating torque | [
"Electric_motor\n\nThe brushless wound-rotor synchronous doubly-fed (BWRSDF) machine is the only electric machine with a truly dual ported transformer circuit topology (i.e., both ports independently excited with no short-circuited port). The dual ported transformer circuit topology is known to be unstable and requ... |
5726d1d8708984140094d241 | What determines continuous torque density? | size of the air-gap area and the back-iron depth | [
"Electric_motor\n\nThe continuous torque density of conventional electric machines is determined by the size of the air-gap area and the back-iron depth, which are determined by the power rating of the armature winding set, the speed of the machine, and the achievable air-gap flux density before core saturation. De... |
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