Tag Archives: Depth of knowledge

Potentiometers

What is a potentiometer?

Variable resistors, as the name implies, have a terminal resistance that can be varied by turning a dial, knob, screw, or whatever seems appropriate for the application. They can have two or three terminals, but most have three terminals. If the two- or three-terminal device is used as a variable resistor, it is usually referred to as a rheostat. If the three-terminal device is used for controlling potential levels, it is then commonly called a potentiometer. Even though a three-terminal device can be used as a rheostat or a potentiometer (depending on how it is connected), it is typically called a potentiometer when listed in trade magazines or requested for a particular application.

(a) potentiometer symbol; (b) and (c) rheostat connections; (d) rheostat symbol

Potentiometer: (a) External, (b) Internal, (c) Circuit equivalent. (Don Johnson Photo)

How to wire a potentiometer in the circuit?

Terminal a: This is the output of the pot, which means it should be wired to the circuit’s input.

Terminal b: This the input of the potentiometer, meaning the output line from the circuit should connect to it.

Terminal c: Connect it to the ground.

How to measure a potentiometer in the circuit?

  1. The resistance between the outside terminals a and c is always fixed at the full rated value of the potentiometer, regardless of the position of the wiper arm b.
  2. The resistance between the wiper arm and either outside terminal can be varied from a minimum of 0 Ω to a maximum value equal to the full rated value of the potentiometer.

Measurement: (a) between outside terminals; (b) between wiper arm and each outside terminal.


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EMT1255L

“Electonics Laboratory”

Course Description:

Non-linear behavior using semiconductor devices from diodes to CMOS ICs. A black box analysis of amplifiers and other circuits is introduced, as well as basic optical devices. Typical circuits are bread-boarded, analyzed and tested in the laboratory. Computer simulations are used for the additional reinforcement of course material.

Course Learning Outcomes:

Upon successful completion of this course, the student will be able to:

  1. Understand the structures & principles of semi-conductor devices (Diodes, BJT Transistors, JFET Transistors, & OP-AMP IC Chips).
  2. Understand the configurations & principles of basic electronic circuits
  3. Master the circuit-calculation theories
  4. Be able to analyze and to design electronic circuits.
  5. Acquire trouble-shooting knowledge and hands-on technical skills.

Required Materials:

Lab Manual Book
EMT 1255 Lab Kit
EMT1150 Lab Kit if available
Phillips screwdriver


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EMT1250L

“Fundamentals of Digital Systems Laboratory”

Course Description:

Students learn how to implement and analyze control functions and arithmetic operations using digital IC’s. Computer techniques are used to simulate systems and troubleshooting. Laboratory problem solving through the synthesis, breadboarding and testing of such systems. State-of-the-art integrated circuits are used with each student working with their individual digital trainers.

Course Learning Outcomes:

Upon successful completion of this course, the student will be able to:

  1. Understand the logic functions (AND, OR, NOT, and so on) through building simple circuits on their own digital trainer.
  2. Analyze and design basic combinational SOP and POS logic systems.
  3. Apply various simplification techniques to combinational logic.
  4. Be familiar with Altera’s Quartus II software to design and simulate simple combinational circuits.
  5. Determine waveforms and state diagrams with SR, D and JK filp-flops.
  6. Analyze and design basic sequential logic systems including counters.
  7. Encode Boolean expression and truth table in VHDL using concurrent signal assignment statements.
  8. Program Altera DE2 board with their schematic and VHDL designs.

Required Materials:

Lab Manual (handout)
EMT 1250 Lab Kit
Digital Trainer from EMT1130
Altera DE2 Board
Phillips screwdriver


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EMT1150L

“Electrical Circuits Laboratory”

Course Description:

Introduction to dc and ac circuits. Topics include Ohm’s Law,  Watt’s Law, resistance, series, parallel, and series-parallel circuits, network theorems, equivalent circuits, capacitive and inductive circuits, as well as ac circuits. Students are required to build and test electrical circuits using electrical components and software application.

Course Learning Outcomes:

Upon successful completion of this course, the student will be able to:

  1. Understand, analyze, and safely use basic electrical and electronic circuits/systems and electromechanical devices
  2.  Troubleshoot and fix problems in electrical circuits/systems and electromechanical devices
  3.  Use the tools and instruments to build electromechanical devices
  4. Demonstrate proficiency in oral and written communication skills using appropriate technology
  5. Function as effective contributing members of a team
  6. Recognize the physical laws that govern how all electrical circuits and devices work
  7. Apply fundamental mathematical principles to their electronics work
  8. Calculate current, voltage, resistance, power, and recognize voltage sources, resistor color code, and VOMs
  9. Apply Ohm’s Law and Watt’s Law to electronic circuits, developing their basic skills of problem solving and critical thinking by solving basic problems
  10. Apply the basic rules of series and parallel circuits
  11. Analyze and simplify series-parallel circuits, use Thevenin’s Theorem, and Wheatstone Bridge
  12. Wire circuits, use lab equipment, test and troubleshoot circuits, make graphs, write lab reports, and perform computer simulations (Multisim) in lab for problem solving. They will begin to develop team skills by working in small teams
  13. Recognize alternating current, frequency, the oscilloscope, capacitors and inductors – in series, in parallel and in AC or DC circuits, and some important applications.

Required Materials:

Electrical Circuits Lab Manual
EMT 1150 Lab Kit
Phillips screwdriver
Extra .5A /250V fuses

Helpful Hints:

  1.  You may get assistance in the Tech Learning Center.
  2.  Students who are failing should consider officially withdrawing on or before the Withdrawal Date to avoid an F or WU grade.
  3. Study in groups. Studies have shown that students who study in this manner perform better in all of their classes. SO MAKE FRIENDS.
  4. Do your homework and seek help immediately for any difficulties that arise. Don’t wait until the night before the work is due.
  5. Don’t expect every concept to be crystal clear after a single reading.More than one reading of a section may be necessary.
  6. Work through the example problems step by step before trying the related problems.
  7. Review the chapter Summary and equation list. Take the multiple choices self-test.

 


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