• Study Resource
  • Explore Categories
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload


... The phenomenon of voltages and currents on motor and generator shafts has been known for the past 100 years. It affects motors, hydro generators and turbo generators. There has been an increase in occurrences and intensity of shaft current damages as machines became larger, particularly on high spee ...
AP1120
AP1120

... 4. Line and load regulation are guaranteed up to the maximum power dissipation of 15W. Power dissipation is determined by the input/output differentially and the output current. Guaranteed maximum power dissipation will not be available over the full input/output range. 5. Quiescent current is defin ...
700 Series
700 Series

... • Resistance, function is not to be performed on circuits capable of delivering greater than 600 Volts. • Frequency, Capacitance and Continuity functions are not to be performed on circuits capable of delivering greater than 500 Volts. 2. To avoid electrical shock hazards and ...
Simulation of DC-DC Converter-Fed BLDC Motor Drive for PFC
Simulation of DC-DC Converter-Fed BLDC Motor Drive for PFC

... household applications such as fans, water pumps, blowers, mixers, etc. [1], [2]. The use of the brushless direct current (BLDC) motor in these applications is becoming very common due to features of high efficiency, high flux density per unit volume, low maintenance requirements, and low electromag ...
High Efficiency NPC Multilevel Converters using Super
High Efficiency NPC Multilevel Converters using Super

High Accuracy Ultralow I , 300 mA, anyCAP Low Dropout Regulator
High Accuracy Ultralow I , 300 mA, anyCAP Low Dropout Regulator

... low as 1.0 µF is all that is needed for stability; larger capacitors can be used if high current surges on the output are anticipated. The ADP3333 is stable with extremely low ESR capacitors (ESR ≈ 0), such as multilayer ceramic capacitors (MLCC) or OSCON. Note that the effective capacitance of some ...
EE-3306 HC6811 Lab #4
EE-3306 HC6811 Lab #4

... Procedure for the Lab: In this lab, you will program the A/D converter to read inputs PE0 – PE3 and output the result to the LCD display. To learn more about the A/D converter in 68HC11 go through the reference manual from pages 471-478. The 68HC11 A/D system is an 8 bit successive approximation con ...
Majenko Technologies
Majenko Technologies

Manual-amp heads R2
Manual-amp heads R2

... or cooling fans and is capable of driving loads as low as 2 ohms. AC power and output speaker jacks are located on the rear of the chassis. A standard, threeprong detachable AC power cord is used to provide power to the unit, while AC voltage selection switch allows the unit to operate at 115V/60 Hz ...
UMX SERIES
UMX SERIES

... low input currentTHD as well as high output efficiency. ...
The LM1881 Video sync separator extracts timing
The LM1881 Video sync separator extracts timing

performance analysis of a single-phase ac voltage
performance analysis of a single-phase ac voltage

... the heart of this motion control is variable speed drives (VSDs). An induction motors (AC drives) are widely used VSDs as a result of its low maintenance cost while offering equal and often superior dynamic performance over their DC drives counterparts in all possible scales (Large, Medium and small ...
Standing Wave Patterns
Standing Wave Patterns

... the voltage standing wave pattern initially increases when moving from load to generator and reaches a maximum first. ...
AN-178 Rev. New - Holt Integrated Circuits
AN-178 Rev. New - Holt Integrated Circuits

... feature of the HI-8195 family is the power down open-circuit of the switches. This feature is very useful in ARINC 429 bus applications. All analog switches exhibit very low supply current on the VLOGIC, V+ and V- pins. Three versions are available, featuring different combinations of normally open ...
Horsepower and Torque Outline
Horsepower and Torque Outline

Will High Power Impulse Magnetron Sputtering (HIPIMS)
Will High Power Impulse Magnetron Sputtering (HIPIMS)

... HIPIMS utilizes extremely high power densities of the order of kWcm−2 in short pulses (impulses) of tens of microseconds at low duty cycle (on/off time ratio) of <10 %. A distinguishing feature of HIPIMS is its high degree of ionization of the sputtered metal and high rate of molecular gas dissociat ...
Evaluate:  MAX2472/MAX2473 MAX2472/MAX2473 Evaluation Kits General Description Features
Evaluate: MAX2472/MAX2473 MAX2472/MAX2473 Evaluation Kits General Description Features

... This section describes the circuitry surrounding the IC in the MAX2472/MAX2473 EV kits. For more detailed information covering device operation, please consult the MAX2472/MAX2473 data sheet. Figure 1 shows the schematic for the MAX2472/ MAX2473 EV kits. Input capacitors C7 and C8 are 100pF DC-block ...
LPC-MT-2138
LPC-MT-2138

... ARM7TDMI-S CPU with real-time emulation and embedded trace support, that combine the microcontroller with 512 kB of embedded high-speed flash memory. A 128-bit wide memory interface and a unique accelerator architecture enable 32-bit code execution at maximum clock rate. with these features: ...
RA07M0608M 数据资料DataSheet下载
RA07M0608M 数据资料DataSheet下载

... to guarantee the level of reliability typically deemed necessary for critical communications elements. Examples of critical communications elements would include transmitters for base station applications and fixed station applications that operate with long term continuous transmission and a higher ...
PaperBramFaesv02
PaperBramFaesv02

Evaluates:  MAX8662 MAX8662 Evaluation Kit General Description Features
Evaluates: MAX8662 MAX8662 Evaluation Kit General Description Features

... section of the MAX8662/MAX8663 IC data sheet for more information. The output voltages for OUT4–OUT7 are set by jumpers SL1 and SL2. See Table 3 and refer to the Linear Regulators (OUT4, OUT5, OUT6, and OUT7) section of the MAX8662/MAX8663 IC data sheet for more information. ...
Band for Microwave Power Transmission
Band for Microwave Power Transmission

... where Pt is the power of the emitter, Gt and Gr are the emitter and receiver antenna gain respectively, λ is the wavelength used and R is the distance separating the emitter and the receiver. The available power at a certain distance from the emitter decreases as the frequency increases. Frequencies ...
IRIS POWER Volume 1, Issue 1 February 2006
IRIS POWER Volume 1, Issue 1 February 2006

... the presence of inverter voltage impulses. Qualification and Testing of Stator Insulation Systems for Inverter Duty Motors Probably the most important new technical specification concerning machine insulation systems to be developed in the past 20 years is IEC 60034 Part 18 - 41: Rotating Electrical ...
Blackstart of An Induction Motor in An Autonomous Microgrid
Blackstart of An Induction Motor in An Autonomous Microgrid

LF411 Low Offset Low Drift JFET Input Operational Amplifier
LF411 Low Offset Low Drift JFET Input Operational Amplifier

< 1 ... 697 698 699 700 701 702 703 704 705 ... 1202 >

Pulse-width modulation



Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a modulation technique used to encode a message into a pulsing signal. Although this modulation technique can be used to encode information for transmission, its main use is to allow the control of the power supplied to electrical devices, especially to inertial loads such as motors. In addition, PWM is one of the two principal algorithms used in photovoltaic solar battery chargers, the other being MPPT.The average value of voltage (and current) fed to the load is controlled by turning the switch between supply and load on and off at a fast rate. The longer the switch is on compared to the off periods, the higher the total power supplied to the load.The PWM switching frequency has to be much higher than what would affect the load (the device that uses the power), which is to say that the resultant waveform perceived by the load must be as smooth as possible. Typically switching has to be done several times a minute in an electric stove, 120 Hz in a lamp dimmer, from few kilohertz (kHz) to tens of kHz for a motor drive and well into the tens or hundreds of kHz in audio amplifiers and computer power supplies.The term duty cycle describes the proportion of 'on' time to the regular interval or 'period' of time; a low duty cycle corresponds to low power, because the power is off for most of the time. Duty cycle is expressed in percent, 100% being fully on.The main advantage of PWM is that power loss in the switching devices is very low. When a switch is off there is practically no current, and when it is on and power is being transferred to the load, there is almost no voltage drop across the switch. Power loss, being the product of voltage and current, is thus in both cases close to zero. PWM also works well with digital controls, which, because of their on/off nature, can easily set the needed duty cycle.PWM has also been used in certain communication systems where its duty cycle has been used to convey information over a communications channel.
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report