EUT 1040 - University of Minnesota Duluth

EUT 1040 - University of Minnesota Duluth

EE 4501 Rectifiers, Switches and Power Supplies Transformers and Isolation Primary and Secondary connected only through magnetic circuit (Electrically

Isolated) Implies that Grounding Point of Primary Need Not Be Coordinated with that of Secondary Isolation

Diode - AC Performance Vd = 0.6 V for Forward Current Open Circuit for Reverse Current Reverse Recovery Characteristic a measure of the time it takes to turn off the current during trnasition from forward bias to reverse bias

Half-Wave Rectifier One Diode Only Forward Current - Positive Average (Vpk/PI) Vavg approximately (Vo Vdiode)/PI Full-Wave Rectifier

2 Diodes -Reverse Current Commutated Center-Tapped Transformer - Isolation allows change of grounding point Vavg approx. 2(Vo-Vdiode)/PI Bridge Rectifier 4 Diodes - No Need for Center-Tapped

Transformer Vavg approx. 2(Vo - 2Vdiode)/PI Ripple Current Filter Use Capacitor to Minimize AC Ripple Ic = C dV/dt

Conventional Power Supplies Basic Features of Power Supply (AC to DC): Rectifier Circuit -Transformer & Diode Bridge & Filter Overcurrent Protection - Fuse or Breaker Voltage Regulator - Constant Output Volts Across Current Range

Anti-Reverse - Diode Blocks Reverse Current from Entering Supply Crowbar - Overvoltage Applied to Terminals Initiates Short-Circuit to Blow Fuse Conventional Power Supply

Switch-Mode Power Supplies Use Power Electronics to Chop AC waveform Used in Modern Computers Many Other Applications Compact and Efficient

Power Electronics High Voltage (100s of Volts) High Current (10s of Amps) High Power Transistors, SCRs Power BJT, IGBT Power MOSFET Power Diode

Thyristor (Power SCR), GTO High Power DC Switch Use Power Transistor as a Switch (On/Off) on a Power Circuit Small Signal (Low power) Controls Large Signal (Like a Relay)

Combine with Inductors and Capacitors for Wave-Shaping Power MOSFETs Hundreds of Volts Tens of Amps Low Gate Voltages

Vgs < +/- 20 Volts (DO NOT EXCEED) Fairly Fast Switching times (200 nS) DC-DC Chopper

Power Transistor Chops High Voltage DC into Low Voltage DC (DC to DC Transformation) Chopper Output Waveforms Transistor Chops Voltage into Square Wave Inductor Smoothes Current

Biasing Circuit for P-MOSFET Switch Design Goals: 5V Logic to turn on/off switch Want MOSFET in saturation when on (Vgs=1015V) [Avoid approaching Vgs=+/-20V] Want to control a 24V circuit

Want to protect Logic Source from Transients Design of Biasing Circuit for MOSFET Switch IMPORTANT: |Vgs| < 20 Volts!

Circuit Isolation IMPORTANT to electrically isolate delicate electronics from power circuits (Pulse Width Modulation motor drives, etc) Relays Provide Electric Isolation (magnetic circuit)

Provide electro-mechanical Amplification Low Power Signal Controls Large Power Circuit AC or DC Not for Repetitive Operations

Opto-Couplers Provide Electric Isolation (Energy Transfer via Photons) Many Types of Output: BJT, Darlington Pair, SCR, etc Tri-State Drivers (Buffers)

Enable Pin = 0 puts driver in High Impedance State (Open Circuit A to B) High Input Z, Low Output Z (10 GE output) Non-Inverting or Inverting References Heathkit, Electronic Circuits, EB-6104A,

2002 Alexander, Fundamentals of Circuit Analysis 2nd Edition, McGraw-Hill, 2004

Recently Viewed Presentations

  • Cladograms Honors Science Grade 8 Cladistics  Cladistics  a

    Cladograms Honors Science Grade 8 Cladistics Cladistics a

    This diagram shows a relationship between . 4. relatives. These relatives . share a common ancestor at the root of the tree. Note that this diagram is also a timeline. The . older organism is at the bottom. of the...
  • Python Tips/Tricks Scripting Rest Service Downloads Tom Laue

    Python Tips/Tricks Scripting Rest Service Downloads Tom Laue

    #format selection statement differently if the field is text or numeric. if str(' ') in DifferentValues: DifferentValues.remove(' ') ... Log file stores every print statement Python makes running the script. Has anybody ever closed the script results .
  • Capabilities Presentation - E-Squillace

    Capabilities Presentation - E-Squillace

    Agenda. General Changes & Trendswith SQL Server 2012 Courses & Exams. SQL Server Courseware Portfolio. Curiously Absent… Final Comments. Appendices. Much of the content for this presentation was derived or directly taken from a presentation to Microsoft Certified Trainers (MCTs)...
  • Annual Review of MTA Sponsored Pension & Retirement

    Annual Review of MTA Sponsored Pension & Retirement

    Combined pension plans assets under management grew 18.7% year over year . OPEB Trust: $370.6 million. Strong performance for 2017. The Plans are designed to perform equal to or better than a traditional 60% Equity / 40% Bond benchmark over...

    (Note: John Cabot's real name was Giovanni Caboto. He was born in Italy around 1455) (Note: There is evidence that the first explorers from Europe where the Vikings who came 500 years earlier but they didn't stay.) ... Sealers shoot...
  • True or False? Sales are rising rapidly! 4370

    True or False? Sales are rising rapidly! 4370

    True or False?There are more 15 year old boys than girls. 15 year olds. 16 year olds. 18 year olds. 17 year olds. 15 year olds. 16 year olds. 18 year olds
  • Názvosloví Anorganických Sloučenin

    Názvosloví Anorganických Sloučenin

    Autorem materiálu a všech jeho částí, není-li uvedeno jinak, je RNDr. Pavlína Kochová. CZ.1.07/1.5.00/34.0501. Typ interakce. DUM se skládá z výkladu formou prezentace a o následnou aktivitu formou pracovního listu, v závěru prezentace jsou tabulky shrnující používané pojmy - jednoduché...
  • Building Java Programs - University of Washington

    Building Java Programs - University of Washington

    ArrayList, LinkedList, HashMap, TreeSet, PriorityQueue all collections are in the java.util package import java.util.*; Lists list: a collection of elements with 0-based indexes elements can be added to the front, back, or elsewhere a list has a size (number of...