EE 421 Electronics III

1996-97 Catalog Data: 3 credits

Electronic equipment design with emphasis on design approach, design techniques and establishing design requirements from actual practical design situations using devices studied in prerequisite courses including diodes, transistors, op amps, timers, voltage regulators, thyristors, circuit protection devices, switching power supplies, power transformers, optoisolators, relays, etc. Analysis of commercial electronic equipment schematics and device data sheets will be an integral part of the course. Prerequisite: EE 322.

Textbooks:

None. The course will emphasize Manufacturer's data sheets, application notes, and DigiKey component catalog.

Manufacturer's Data Sheets: Selected specification sheets on a variety of discrete components including IC regulators, thyristors, fuses, relays, transistors, diodes, etc.

Application Notes: Selected notes from Texas Instruments, Maxim, National, Teccor, Thermalloy, Linear, SGS-Thompson, etc. These application notes are copied and given to the students as required information to work assignments.

Digi Key. Electronic component catalog issued to each student at the beginning of the semester.

Reference:

The Art of Electronics. Hill and Horowitz

Microelectronic Circuits. Sedra and Smith

The Voltage Regulator Handbook, Texas Instruments, Inc.

Voltage Regulator Handbook, National Semiconductor

Linear Databook, National Semiconductor

Application Notes, Ap notes from various companies covering subjects such as cooling the power transistor, thyristor triggering circuits, timer design using the 555/556 IC timer, circuit applications for the Triac, SCR zero crossing circuits, determining maximum reliable load lines for power transistors, thermistors-sensitive sensors, twenty ways to wreck a relay, relay reliability and life, switching power supplies, solid state optoelectronic devices, design guide for wire and cable, relay technical databook, etc. These are copied and given to each student as background information.

Potter and Brumfield, Electromechanical Products Technical Databook

SPD Electrical Protection Handbook, Bussman

Introduction to Solid State Power Electronics, Westinghouse

Standard Transformers for Design Engineers, Stancor

Coordinator:

Dr. J. Ramirez, Associate Professor of Electrical and Computer Engineering

Goals:

Students completing EE 421 should have an understanding of methodology to integrate discrete solid state components that they have studied in prerequisite courses into a completed design project. Students will apply the theory they have learned to solving practical design problems resulting in a complete equipment design. They will develop practical "rules of thumb in applying resistors, capacitors, solid state components, electromechanical devices, and circuit protection devices to their designs. They will develop a general design approach that can be used to solve design problems encountered on the job. Emphasis will be placed upon helping the student realize that most design problems have many answers and that their job is to provide a workable correct answer whatever their selected approach. A considerable amount of time will be directed towards developing an effective linear electronics vocabulary.

Most of the grade will be based upon the student providing the best solutions to the problems assigned. However, part of the grade will be placed upon the student's ability to generate reasonable approaches, effective written progress reports, cost effectiveness.

Topics:

1. Introduction to design methodology. Steps to a successful design, approach to developing block diagrams as a design tool, electrical power management, schematic drawing, use of catalogs/spec sheets, cost considerations and the need to keep designs as simple as practicable. The reporting requirements of the class will be established. A comprehensive semester problem will be assigned and a block diagram will be required that establishes requirements for each block and anticipated power requirements. 4 classes.
2. Power Amplifier Design - Design audio power amplifiers using BJTs, Darlington, MOSFETs, and power ICs as building blocks. Rule-of-thumb biasing techniques for transistors, and single ended power supplies for power ICs. Design of phase splitters using op amps, discrete transistors, and single stage amplifiers to drive class AB amplifiers. Application of heat sinks to power devices will also be covered. Each student will design a power amp using each major device type and select the best for cost, weight, and efficiency. 4 classes.
3. Application of Function Generator and Timing ICs - Commercially available function generator ICs will be covered and design of circuits to amplify/buffer the output signals and condition them to useful levels will be accomplished. Emphasis will be placed upon designing circuits for temperature stability using off the shelf/standard value capacitors, resistors, potentiometers, Long-range and short range timer ICs establishing delays from seconds to hours. Each student will design a function generator circuit that will provide the signal for the power amp. Peripheral assignments will be for various amplifiers to condition other outputs from the function generator chip. 4 classes.
4. Introduction to DC power regulation. Three terminal IC regulators configured as constant current and constant voltage regulators. Switching power supplies in buck, boost, and inverting configurations. Fixed and adjustable DC regulators in both linear and switching configurations. Each student will design circuits using each of the configurations to power various circuits including TTL, CMOS, and a general variable DC power supply. A switching power supply will be designed that will power the power amp for a specified time from a lead acid rechargeable battery. 4 classes.
5. Application of Batteries to Portable System Design. Battery sizing for portable equipment including discharge characteristics, recharging techniques, cycle life, and storage life, A battery charger will be designed that will provide cyclic and standby service for the power amp previously designed. Switching devices such as relays, photoisolators, thyristors, and manual switches will be used. Design will include LEDs and incandescent panel lights as Indicators. Nickel Cadmium, Nickel Metal Hydride, and various primary battery types will be compared in performance to the lead acid suspended electrolyte battery. 8 classes.
6. Unregulated DC Power Generation. Ac to DC conversion process using half-wave and full-wave rectification and capacitive filtering, circuit protection devices. Both Schade charts and rules of thumb will be used to establish filter capacitor size. Designs using power diodes, power diode bridges, and power transformers in full-wave, and half-wave configurations will be required. An unregulated DC power supply will be designed that will provide power for the battery charger. Comparisons of full wave and half wave rectification characteristics will be made and the student must select the best configuration for their particular design. The designs will include fuses and transient suppression. AC power noise, transients, brownouts, surges, sags, etc., will be explained and preventative measures incorporated into the design. 4 classes.
7. Review and Wrap-up. Provide final schematic of overall system, final report, cost, weight, etc. Also, provision for extra credit demonstrations/reports to the class. Comprehensive final review. 2 classes.

Computer Usage:

1. Students will be encouraged to use a word processor to generate progress and problem reports.
2. SPICE electronic design program
3. FilterCad - A software program designed by Linear Technology Corporation for the design of active op amp filters.
4. Simple Switcher Design - A program provided by National Semiconductor to select components for their line of switching DC-DC regulators.

Laboratory Projects:

1. Students will be divided into groups of 2. They will be assigned a prototyping board and a basic tool kit. The first class period will be spent instructing students the basics of soldering. Each will be given circuit boards and must complete 20 acceptable solder joints. 1 session.
2. Functionally testing components for critical design parameters including thyristor switching and hold-in characteristics, power transformer secondary resistance, fuse and circuit breaker "blow/trip" characteristics, resistor power dissipation characteristics, relay hold-in and drop-out characteristics, electrolytic capacitor leakage characteristics, LED biasing, resistor power dissipation characteristics, etc. Elementary circuits will be designed and prototyped using these components. 2 sessions.
3. Students will prototype and test the semester design project. This includes an audio amplifier, function generator, fixed and adjustable linear regulators, switching power supply. If time allows, the battery charger and AC-DC converter will be prototyped. Remaining sessions.

ABET Category Content:

Engineering science: 1/2 credit or 13%

Engineering design: 2 1/2 credits lecture and 1 credit lab or 87%

Prepared by:

David Pippen

Date: February 17, 1994