flow of electrons so that you can better operate your radio. Basic Characteristics of Electricity There are **three** characteristics of electricity: Voltage Current Resistance Basic Characteristics of Electricity Voltage Electromotive force (EMF) causing electrons/kind of resistance to the flow of **AC** called reactance (X). Reactance also measured in Ohms (Ω). Reactance & Impedance In **circuits** containing capacitors or inductors, voltage & current are “out of **phase**”. Current flow changes before the voltage changes/

current is The rms current is Monday, Apr. 24, 2006PHYS 1444-501, Spring 2006 Dr. Jaehoon Yu 13 **AC** **Circuit** w/ LRC The voltage across each element is –VR –VR in **phase** with the current –VL –VL leads the current by 90 o –VC –VC lags the current by 90 o/ will not be the simple sum of the **three** Let’s try to find the total impedance, peak current 00 and the **phase** difference between 0 0 and V0.V0. Monday, Apr. 24, 2006PHYS 1444-501, Spring 2006 Dr. Jaehoon Yu 14 **AC** **Circuit** w/ LRC The current at any instance is/

by The current is (π/2) rad = 90 o out of **phase** with the voltage 15 Capacitors in **AC** **circuit** 16 Capacitors in **AC** **circuit** The phasor diagram shows that for a sinusoidally applied voltage, the current/**circuit** The instantaneous voltage across each of the **three** **circuit** elements can be expressed as 22 RLC series **circuit** In series, voltages add and the instantaneous voltage across all **three** elements would be Δv = Δv R + Δv L + Δv C –Easier to use the phasor diagrams 23 RLC series **circuit**/

1 ELECTRICAL **CIRCUIT** ET 201 Become familiar with the operation of a **three** **phase** generator and the magnitude and **phase** relationship. Be able to calculate the voltages and currents for a **three** **phase** Wye and Delta connected generator and load. 2 **THREE** **PHASE** SYSTEMS 3 23.1 – Introduction If the number of coils on the rotor is increased in a specified manner, the result is a polyphase **ac** generator, which/

peak-to-peak and rms Capacitive Reactiance magnitude and **phase** Inductive Reactance magnitude and **phase** **AC** **Circuits** **AC** Signals and rms Values There are a number of ways to describe the current or voltage for a time varying signal: peak value, peak-to- peak, and rms. Write in your own words what each means and indicate the **three** values on the sine wave signal shown below/

) Or energy is stored in the magnetic field and eventually flows into the electrical **circuit** that powers the stator – generator Synchronous Machine Construction DC field windings are mounted on the (rotating) rotor - which is thus a rotating electromagnet **AC** windings are mounted on the (stationary) stator resulting in **three**-**phase** **AC** stator voltages and currents The main part in the synchronous machines are i) Rotor/

transformers Used to transfer energy from one **AC** **circuit** to another Frequency remains same in both **circuits** No ideal transformer exists Also used in metering,/**Three** **phase** transformers Large scale power generation - Generally 3 **phase** Requires use of 3 **phase** step-up and step-down transformers 3 **phase** transformer - Combination of 3, single- **phase** transformers (**three** primary and **three** secondary windings mounted on a core having **three** legs) Commonly used configurations: –3 **phase** **three** wire (Delta) –3 **phase**/

the dc field current to the machines. A brushless exciter is a small **ac** generator with its field **circuit** mounted on the stator and its armature **circuit** mounted on the rotor shaft. Construction of **Three** **Phase** Synchronous Machines (A Brushless Exciter **Circuit**) A small **three** **phase** current is rectified and used to supply the field **circuit** of the exciter, which is located on the stator. The output of the/

special kind of resistance to the flow of **AC** is called reactance (X). Reactance also measured in Ohms (Ω). Components Reactance and Impedance. In **circuits** containing capacitors or inductors, voltage & current are “out of **phase**”. Current flow changes before the voltage changes/Oscillator B.Potentiometer C.Transistor D.Voltmeter T6B04 -- Which of the following components can be made of **three** layers of semiconductor material? A.Alternator B.Transistor C.Triode D.Pentagrid converter T6B05 -- Which of /

to **three** decimal places. b.Convert the rectangular coordinates (-3.207, -5.719) to polar coordinates with in degree measure, -180° ˂ ˂ or = 180°, and r ˃ or = 0. 10.Change x² + y² - 4y = 0 to polar form. 28 HOW COMPLEX NUMBERS ARE APPLIED TO **AC** **CIRCUITS** **Circuit** Values Expressed/ between 0° and 90° 3.Which property of a sine wave does the length of a phasor represent? a) Frequency. b) **Phase**. c) Amplitude. d) Instantaneous value 4.Refer to Fig. 5.5.1: Which of the following statements about Fig 5.5.1/

current by 90°. Section 33.5 i and v **Phase** Relationships – Equations The instantaneous voltage across each of the **three** **circuit** elements can be expressed as Section 33.5 More About Voltage in RLC **Circuits** ΔV R is the maximum voltage across the resistor / when the current begins to decrease in the **circuit**, the energy is returned to the **circuit**. The power delivered by an **AC** **circuit** depends on the **phase**. Some applications include using capacitors to shift the **phase** to heavy motors or other inductive loads so /

power-factor compensation capacitor to create "free power” from the unused portion of the **AC** cycle 145Practical **Circuits** E7D17 What is the primary reason that a high- frequency inverter type high-voltage /ohms 231Practical **Circuits** E7H Oscillators and signal sources types of oscillators; synthesizers and **phase**-locked loops; direct digital synthesizers 232Practical **Circuits** 3 styles of Oscillators used in HAM radio 233Practical **Circuits** Colpitts Hartley Pierce E7H01 What are **three** oscillator **circuits** used /

Rectangular Form 24-10: Complex Numbers in Series **AC** **Circuits** 24-11: Complex Numbers in Parallel **AC** **Circuits** 24-12: Combining Two Complex Branch Impedances 24-13: Combining Complex Branch Currents 24-14: Parallel **Circuit** with **Three** Complex Branches McGraw-Hill© 2007 The McGraw-Hill Companies/of the sum of the squares is vector or phasor addition of two terms in quadrature, 90° out of **phase**. The **phase** angle of the resultant is the angle whose tangent is 0.75. This angle equals 37° 24-7: Magnitude/

. Unit 21 Capacitance in **AC** **Circuits** Capacitive power **phase** relationships. Unit 21 Capacitance in **AC** **Circuits** Inductive VARs and Capacitive VARs. Unit 21 Capacitance in **AC** **Circuits** Frequency Relationships Capacitive reactance (X C ) is inversely proportional to frequency (f). As frequency increases ↑ then capacitive reactance decreases ↓. As frequency decreases ↓ then capacitive reactance increases ↑. Unit 21 Capacitance in **AC** **Circuits** Solving a sample series capacitor **circuit**: **Three** capacitors (10µF, 30/

alternating current electric system. 1888, Nikola Tesla demonstrated the first “polyphase” alternating current (**AC**) electrical system. His **AC** system includes everything needed for electricity production and use such as the electric generator, /**circuit** at the work site, double-point grounding must be used. Single Point Grounding **Phase** Conductor Jumpers Ground Jumper Neutral Jumper Cluster Bar (chain binder) below working position Jumpers connect all **three** **phases** together. Jumper connects cluster bar to **phases**/

to ground to protect operator from being electrocuted) mAs meter is used for very short exposures 3) Rectifier Purpose – converts **AC** to DC to prevent reverse bias Location – Between secondary of step-up transformer and x-ray tube 4) Cables to x/ 12 rectifiers or 12 pulses with 12 rectifiers (3 Ǿ, 6 p = 13% ripple, 3 Ǿ 12 p = 3% ripple **Three** **Phase** Generator **Circuits** To work properly must have 3 primary & secondary windings in transformer (one for each current) Must have 3 autotransformers (one for each/

in series, the total capacitive reactance is the sum of the individual reactances. Assume **three** 0.033 mF capacitors are in series with a 2.5 kHz **ac** source. What is the total reactance? The reactance of each capacitor is 5.79 /**phase**. No true power is dissipated by a capacitor, because stored energy is returned to the **circuit**. The rate at which a capacitor stores or returns energy is called reactive power. The unit for reactive power is the VAR (volt-ampere reactive). Rectifiers Convert a sinusoidal wave (**ac**/

© 2003-2009 Ran Ginosar048878 Lecture 4: Speed-Independent Control **Circuits** 78 a0+ a1+ r0+ A+ rCf+ rCt+ **aC**- r1+ R+ Input Free Choice P3P1 **aC**+ P2 rCf- rCt- P4P4 r0-r0- r1-r1/**three** solutions. Decide which **three** comparison criteria to use © 2003-2009 Ran Ginosar048878 Lecture 4: Speed-Independent Control **Circuits** 95 Data Validity © 2003-2009 Ran Ginosar048878 Lecture 4: Speed-Independent Control **Circuits** 96 Four Channel Types © 2003-2009 Ran Ginosar048878 Lecture 4: Speed-Independent Control **Circuits** 97 2 **phase**/

EYEY EBEB ZRZR IYIY IBIB ZBZB ZYZY VBVB ININ ZNZN VNVN 3-wire system (no neutral line ) ERER **Three**-**phase** Load **Three**-**phase** **AC** generator VYVY IRIR VRVR EYEY EBEB ZRZR IYIY IBIB ZBZB ZYZY VBVB VNVN 3-wire system (no neutral line ) No neutral line = open **circuit**, Z N = ∞ 43 44 VNVN = ERER ZRZR + EYEY ZYZY + EBEB ZBZB 1 ZNZN + 1 ZRZR + 1 ZYZY + 1/

**circuits** Mechanical Harmonic Oscillator LC **Circuit** Oscillations Damped Oscillations in an LCR **Circuit** **AC** **Circuits**, Phasors, Forced Oscillations **Phase** Relations for Current and Voltage in Simple Resistive, Capacitive, Inductive **Circuits**. Summary Copyright R. Janow – Spring 2015 LC and RC **circuits** with constant EMF - Time dependent effects R C E R L E Growth **Phase** Decay **Phase** Now LCR in same **circuit**/– 3: The **three** LC **circuits** below have identical inductors and capacitors. Order the **circuits** according to their /

C/S 240 Volts xxii) a) Rated supply voltage of (closing and operating devices and auxiliary **circuits** ~ 1)1 10 y dc/so vdc 2) 240 Volts **AC** 50 C/S single **phase** 3) 415 Volts 50 Hz **three** **phase** b) Permissible voltage variation 1) m case of DC Power supply voltage 11 variation shall be between 85% to 1 10% 1 of normal voltage/

XY Driver’s circiuit 3) Input **circuit** of Motor Driving power **circuit** content it designs based 3-**phase**, but now small head is using one-**phase**, so only 1,2 line is using. it’s changed from **AC** 220V to Motor Driving DC 310V. 3. **Circuit** Interaction # XY Driver Board 4. Understanding/-state 74HC244; 74HCT244 3-state buffer of 8Bit This(IC) is depend on 1th (ENA) and 19th (ENB)’s spec, and the **three** kind of output can come out When 1th and 19th is LOW, the input don’t reverse and the value is output. When 1th and/

not require a special design or additional starting circuitry. Single **Phase**, **Three** **phase** **Circuits** b) Single **phase** systems **three**-wire type. Allows connection to both 120 V and 240 V. a) Single **phase** systems two-wire type Two-**phase** **three**-wire system. The **AC** sources operate at different **phases**. **Three**-**phase** Generator The **three**-**phase** generator has **three** induction coils placed 120° apart on the stator. The **three** coils have an equal number of turns, the voltage/

equation The RMS value of output voltage, output current, and thyristor current can then be calculated. 4.1.2 **Three**-**phase** **AC** voltage controller Classification of **three**- **phase** **circuits** 3- **phase** 3- wire Y connection **AC** voltage controller For a time instant, there are 2 possible conduction states: – Each **phase** has a thyristor conducting. Load voltages are the same as the source voltages. – There are only 2 thyristors conducting/

is that toroidal cores contain most of the magnetic field within the core material. Amateur Radio Extra Class **Circuits** & Resonance for All! E6D13… Forty **three** turns of wire will be required to produce a 1-mH inductor using a ferrite toroidal core that has/the formation of inductive and capacitive fields E5D11 How can the true power be determined in an **AC** **circuit** where the voltage and current are out of **phase**? A.By multiplying the apparent power times the power factor B.By dividing the reactive power /

in DC **circuits** Ohm’s Law for a resistor, R, in an **AC** **circuit** ΔV R,rms = I rms R The same formula applies to the maximum values of v and i Chapter 21 Problem 4 The figure shows **three** lamps connected to a 120-V **AC** (rms) household/ = I max Z This can be regarded as a generalized form of Ohm’s Law applied to a series **AC** **circuit** Summary of **Circuit** Elements, Impedance and **Phase** Angles Problem Solving for **AC** **Circuits** Calculate as many unknown quantities as possible (e.g., find X L and X C ) Be careful with units/

in DC **circuits** Ohm’s Law for a resistor, R, in an **AC** **circuit** ΔV R,rms = I rms R The same formula applies to the maximum values of v and i Chapter 21 Problem 4 The figure shows **three** lamps connected to a 120-V **AC** (rms) household/ = I max Z This can be regarded as a generalized form of Ohm’s Law applied to a series **AC** **circuit** Summary of **Circuit** Elements, Impedance and **Phase** Angles Problem Solving for **AC** **Circuits** Calculate as many unknown quantities as possible (e.g., find X L and X C ) Be careful with units/

responsible for the common phenomena of magnetism encountered in everyday life. Substances respond weakly to magnetic fields with **three** other types of magnetism, paramagnetism, diamagnetism, and antiferromagnetism, but the forces are usually so weak that / to the current in an alternating current (**AC**) **circuit**. Impedance extends the concept of resistance to **AC** **circuits**, and possesses both magnitude and **phase**, unlike resistance, which has only magnitude. When a **circuit** is driven with direct current (DC), there/

DC generator. A presentation of eSyst.org **AC** Generator Figure 2 3-**Phase** Voltages Fig. 3 shows the **three** sine wave voltages produced by the generator. There is a 120 degree time difference between the **three** sine wave outputs. A presentation of eSyst.org/current exceeds the rated current value, the electromagnet has sufficient pull to disengage the switch turning off the voltage to that **circuit**. **Circuit** breakers are available in current ratings of 15, 20, 30 and 40 amperes. Large breakers of 100 to 200 amps/

= 1.5 kΩ R3 = 3 kΩ R4 = 7.8 kΩ R g = 150 Ω Slightly Unbalanced Wheatstone Bridge If **three** of the four resistors in a Wheatstone bridge are equal to R and the fourth differs by 5% or less, we can develop/. Fig 5.13: General **AC** bridge **circuit** The usefulness of **AC** bridge **circuit** is not restricted to the measurement of an unknown impedance. These **circuits** find other application in many communication systems and complex electronic **circuits**, such as for: shifting **phase**, providing feedback paths for oscillators/

industrial drives Construction Basic parts of a synchronous generator: Rotor - dc excited winding Stator - 3-**phase** winding in which the **ac** emf is generated The manner in which the active parts of a synchronous machine are cooled determines its/ PF: |V t |>|E f | for underexcited condition **Three**-**phase** equivalent **circuit** of a cylindrical-rotor synchronous machine The voltages and currents of the **three** **phases** are 120 o apart in angle, but otherwise the **three** **phases** are identical. + I a1 E f1 jX s RaRa /

**AC** motor Drives : Induction Motor Drives Synchronous Motor Drives INDUCTION MOTOR DRIVES **Three**-**phase** induction motor are commonly used in adjustable-speed drives (ASD). Basic part of **three**-**phase** induction motor : Stator Rotor Air gap The stator winding are supplied with balanced **three**-**phase** **AC**/. The efficiency. The power factor of input line of the motor. The equivalent **circuit** : The dc voltage at the rectifier output is : and For a **three**-**phase** rectifier, relates Er and Vd as : Using : If Pr is the slip /

for the same reason indicated for a resistive element. 5 Inductive **ac** **circuit**. Inductive **ac** **circuit** Voltage is 24 volts Peak Inductor Waveforms for Example voltage leads the current by 90 degrees Phasor diagrams for Example. 24.0 V 8.0 **Three** cases of impedance R – C series **circuit** Illustration of sinusoidal response with general **phase** relationships of VR, VC, and I relative to the source voltage/

**Three** **Phase** Controlled Rectifiers Power Electronics **Three** **Phase** Controlled Rectifiers 1 3 **Phase** Controlled Rectifiers Power Electronics 3 **Phase** Controlled Rectifiers Operate from 3 **phase** **ac** supply voltage. They provide higher dc output voltage. Higher dc output power/in the Inversion mode Vdc is negative, Idc is positive and the average load power Pdc is negative. Power flows from load **circuit** to **ac** source. 85 When the converter 2 is switched on, Power Electronics When the converter 2 is switched on, For 2 /

the rms current flowing through the reristor times the resistor (ignore **phase** angle)) Series Resonance occurs when is maximum in this case Transformer Review of 1- **AC** **Circuit** Fundamentals(3) Parallel RLC **circuit** Parallel Resonance occurs when is minimum in this case Transformer The Transformer/ and Example Explained and worked out on Greenboard Transformer Review of balanced **three** **phase** **circuits** Two possible configurations: Star (Y) and delta () Star has neutral, delta does not Transformer Star (Y) connection /

a **three** **phase** **AC** generator as a function of time and as phasors. Define a **three**-wire Y-Y **three** **phase** **circuit** and a four-wire Y-Y **three** **phase** **circuit**. Define the symbols for line to neutral voltages, line to line voltages, line currents, and **phase** impedances that will be used in **three** **phase** **circuits**. Analyze Ohm’s law in a **three**-wire Y-Y **three** **phase** **circuit** and in a four- wire YY **three** **phase** **circuit** using a basic **three** **phase**/

-up transformer - Rpri RL Matching Transformers Impedance (Z) Opposition to current flow in **ac** **circuits** Impedance matching Used to show that the source and load resistances are the same Impedance matching/winding transformers **Three**-**phase** transformers **Three**-**phase** power is used for power transmission and industrial applications. Voltages in a **three**-**phase** system can be transformed with **three** identical single **phase** transformers or one **three**-**phase** transformer. **Three**-**phase** transformers **Three**-**phase** transformers /

Storey: Electrical & Electronic Systems © Pearson Education Limited 2004 OHT 16.1 Power in **AC** **Circuits** Introduction Power in Resistive Components Power in Capacitors Power in Inductors **Circuits** with Resistance and Reactance Active and Reactive Power Power Factor Correction Power Transfer **Three**-**Phase** Systems Power Measurement Chapter 16 Storey: Electrical & Electronic Systems © Pearson Education Limited 2004 OHT 16.2 Introduction The instantaneous power dissipated in a component/

) 10Hz (b) 20Hz Experimental waveforms (1A / 100mV) Conclusion The FPGA-based digital SPWM **AC** induction motor control IC‘s designed to drive **AC** induction motor, In the digital control **circuit** part of its internal architecture consists of a triangular wave generator counter, a **three**-**phase** sinusoidal command produces check value table, the **three**-**phase** sinusoidal command after comparison with the triangular wave generated trigger signal via a/

**Circuit** symbol and device cross-section of a) a Diode **AC** switch (DIAC) and a Triode **AC** switch (TRIAC FET: Field-effect transistor s The JFET is a class of Unipolar semiconductor device which comes in two basic varieties, n or p channel. The device in general `runs in the depletion mode with **three**/ Relationships A. Basic Operation of the Non-Inverting Amplifier **Circuit** has Hi Zin, Low Zo, and no **phase** inversion. “Golden Rule” : In a feedback **circuit** the summing junction Value is driven to equal the reference/

**ac** side to the dc side Two types of inverters: single-**phase** inverters and **three**-**phase** inverters Systems Engineering School of Electrical ABD RAHIM 2008 Switch-Mode DC-**AC** Inverters Applications: **ac** motor drives Uninterruptible **ac** power supplies Where a sinusoidal **ac** / through load when two device in same leg conduct – IL is bypassed from load (buck-bost regulator **circuit**) Systems Engineering School of Electrical ABD RAHIM 2008 Current source inverters Systems Engineering School of Electrical when two device/

**phase** is equal to secondary ampere turns per **phase**. · Total copper area in window, **Ac** = (2 x Number of primary turns x area of cross-section of primary conductor) + ( 2 x Number of secondary turns x area of cross - section of secondary conductor) · On equating we get, · The kVA rating of **three** **phase**/ is extremely important as a component in many different types of electric **circuits**, from small-signal electronic **circuits** to high voltage power transmission systems. · The most important function performed/

inductor in the form of alternating voltage and current 90 degrees out of **phase** with each other. 10 Electronic **Circuits** When the power supply frequency for an **AC** **circuit** exactly matches that **circuits** natural oscillation frequency as set by the L and C components, a / to both sides of a crystal a potential of difference is developed. CRYSTALL OSCILLATOR 17 Electronic **Circuits** The **three** most popular crystal materials are; 1.Rochelle salt: Has the weakest crystal structure 2.Tourmaline:Has the least electrical /

**AC** **Circuits** Most currents and voltages vary in time. The presence of **circuit** elements like capacitors and inductors complicates the relation between currents and voltage when these depend on time. Resistive element -I&V proportional Reactive elements involves derivatives Voltage and current are not simply proportional for reactive elements. Ohm’s law does not apply. Introduction **Three**/both R and L Inductor Voltage Inductor voltage is 90 degrees out of **phase** with resistor voltage and current V L (t) I(t) t /

30-6 LC Oscillations with Resistance ( LRC **Circuit**) The system will be underdamped for R 2 4L/C. Critical damping will occur when R 2 = 4L/C. This figure shows the **three** cases of underdamping, overdamping, and critical /the **circuit** nonoscillating? Copyright © 2009 Pearson Education, Inc. Resistors, capacitors, and inductors have different **phase** relationships between current and voltage when placed in an **ac** **circuit**. The current through a resistor is in **phase** with the voltage. 30-7 **AC** **Circuits** with **AC** Source/

100% effective power utilization. **AC** Volts x **AC** Amps = VA (Volt Amp) Purely Resistive **AC** Load: VA = Watts (same as DC **circuits**) Inductive/Reactive **AC** Load: VA x PF = Watts **AC** Volts x **AC** Amps x PF = Watts A Power Factor of 0.75, means that an installation is using 75% of the power being supplied to it. Aerovox manufactures both single and **three**-**phase** power factor correction capacitors/

**AC** **Circuits** – Background Concepts Overview of this Part **AC** **Circuits** – Background Concepts In this part, we will cover the following topics: Introduction to **AC** **Circuit**/**Circuits** by A. Bruce Carlson, shows a generalized sinusoid. Note that the **phase**, , represents the time shift to the left along the time axis, after dividing by . The **phase** has angular units, usually either radians or degrees. Some Review – Sinusoids – 4 A general sinusoid has the following equation. Note that in this equation there are **three**/

current is The rms current is Wednesday, Apr. 18, 2012PHYS 1444-004, Spring 2012 Dr. Jaehoon Yu 10 **AC** **Circuit** w/ LRC The voltage across each element is –VR –VR in **phase** with the current –VL –VL leads the current by 90 o –VC –VC lags the current by 90 /will not be the simple sum of the **three** Let’s try to find the total impedance, peak current 00 and the **phase** difference between 0 0 and V0.V0. Wednesday, Apr. 18, 2012PHYS 1444-004, Spring 2012 Dr. Jaehoon Yu 11 **AC** **Circuit** w/ LRC The current at any instance/

**AC** **Circuit** Copyright © 2009 Pearson Education, Inc. 30-8 LRC Series **AC** **Circuit** The **phase** angle between the voltage and the current is given by The factor cos φ is called the power factor of the **circuit**. or Copyright © 2009 Pearson Education, Inc. 30-8 LRC Series **AC** **Circuit** Example 30-11: LRC **circuit**/Energy Transported by Waves Copyright © 2009 Pearson Education, Inc. If a wave is able to spread out **three**- dimensionally from its source, and the medium is uniform, the wave is spherical. Just from geometrical /

amplifier oscillation. SJTU Yang HuaMicroelectronic **Circuits** **Three** Parts: PartI: The basic concept/**Circuits** **AC** feedback ， no DC feedback DC feedback ， no **AC** feedback The judgment of DC feedback and **AC** feedback SJTU Yang HuaMicroelectronic **Circuits** Example ： feedback ？ Positive or negative ？ DC or **AC** ？ **AC** and DC negative feedback SJTU Yang HuaMicroelectronic **Circuits**/ using bode plot SJTU Yang HuaMicroelectronic **Circuits** Balance condition: Magnitude condition: **Phase** Condition: Start up oscillation condition: /

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