Ohm’s law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship:

where I is the current through the conductor in units of amperes (A), V is the voltage measured across the conductor in units of volts (V), and R is the resistance of the conductor in units of ohms (Ω). More specifically, Ohm’s law states that the R in this relation is constant, independent of the current.

Here are the EMT1250 Lab Exercises.

EXPERIMENT #0: Digital Trainer and Trouble shooting

EXPERIMENT # 1: Schematic Diagrams, Electronic Test Equipment

EXPERIMENT # 2: Basic Logic Gates

EXPERIMENT #3: NAND and NOR Gates

EXPERIMENT # 4: Combinational Logic Circuits

EXPERIMENT # 5: Universal Capability of NAND and NOR Gates

EXPERIMENT # 6: Quartus II Tutorial and Practice

EXPERIMENT # 7: VHDL and DE2 Board

EXPERIMENT # 8: 7-segment Display with VHDL

EXPERIMENT # 9: Magnitude Comparator Circuit

EXPERIMENT # 10: Implementing Binary Adders

EXPERIMENT # 11: Introduction to D and J-K Flip-Flop

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

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.

How to calculate the value of a resistor using the color coded stripes on the resistor?

Step 1) For the four-band scheme, the bands are always read from the end that has a band closest to it, which means to turn the resistor so that the gold or silver stripe is at the right end of the resistor.

Step 2) Look at the color of the first two stripes on the left end. These correspond to the first two digits of the resistor value. Use the table given below to determine the first two digits.

Step 3) Look at the third stripe from the left. This corresponds to a multiplication value. Find the value using the table below.

Step 4) Multiply the two digit number from step 2) by the number from step 3). This is the value of the resistor n ohms. The fourth stripe indicates the tolerance(=accuracy) of the resistor. For example, a gold stripe means the value of the resistor may vary by 5% from the value given by the stripes.

Resistor Color Codes (with gold or silver strip on right end)

Note: For the value of the resistors, the engineering notation should be used as shown below.

Engineering Notation

Example 1: You are given a resistor whose stripes are colored from left to right shown below. Find the resistor value.

brown, black, orange, gold.

Step 1) The gold stripe is on the right so go to Step 2).

Step 2) The first stripe is brown which has a value of 1. The second stripe is black which has a value of 0. Therefore the first two digits of the resistance value are 10.

Step 3) The third stripe is orange which means x 1,000.

Step 4) The value of the resistance is found as 10 x 1000 = 10,000 Ω = 10kΩ.

The gold stripe means the actual value of the resistor mar vary by 5% meaning the actual value will be somewhere between 9,500 Ω  and 10,500 Ω.

How to use an Oscilloscope? -> Click the video

Operational Instruction (Click here!)

How to use the power supply -> Watch the video

“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

“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

OPERATION

Before taking any measurements, read the Safely Information Section. Always examine the instrument for damage, contamination (excessive dirt, grease, etc.) and defects. Examine the test leads for cracked or frayed insulation. If any abnormal conditions exist do not attempt to make any measurements.

Max. Hold Feature

Press ”MAX” to toggle in and out of the Maximum Hold mode. (Holding the highest reading.) In the MAX mode, the MAX annunciator is displayed and maximum reading arc stored in display register, if the new reading is higher than the reading being displayed, the higher reading is transferred to the display register. A “higher” reading is defined as the reading with the higher absolute value.

The MAX hold function is disable in the frequency count mode, but the MAX annunciator is still displayed.

Voltage Measurements

1. Connect the red test lead to the “VΩ” jack and the black test lead lo the “COM” jack.
2. Set the Function/Range switch to the desired voltage range and press the ”AC/DC” switch to toggle between the desired voltage type. If magnitude of voltage is not known, set switch to the highest range and reduce until a satisfactory reading is obtained.
3. Connect the test leads to the device or circuit being measured.
4. For dc, a (-) sign is displayed for negative polarity; positive polarity is implied.

Current Measurements

1. Set the Function/Range switch to the desired current range and press the “AC/DC” switch toggle between to the desired current type.
2. For current measurements less than 200mA, connect the red test lead lo the “mA” jack and the black test lead to the “COM” jack.
3. For current measurements over 200mA or greater, connect the red test lead to the “10A” jack and the black test lead to the “COM” jack.
4. Remove power from the circuit under test and open the normal circuit path where the measurement is to be taken. Connect the meter in series with the circuit.
5. Use caution when measuring 10 amps on 10A range for 60s, please waiting for 10 minutes for next measurement of 10 amps for safety reason.

Resistance and Continuity Measurements

1. Set the Function/Range switch to the desired resistance I. Set the Function/Range switch to the desired resistance
2. Remove power from the equipment under test.
3. Connect the red test lead to the “VΩ” jack and the black test lead to the “COM” jack.
4. Touch the probes to the test points. In ohms, the value indicated in the display is the measured value of resistance. In continuity test, the beeper sounds continuously, if the resistance is less than 40Ω±20Ω.
5. When using 2000MΩ range; the 2000MΩ range has a fixed 10±1-count offset in the reading. When the test leads are shorted together in the ranges, the meter will display 010. The residual reading must be subtracted from the reading obtained in step 4 when this range is used. For example, when measuring 1100MΩ on the 2000MΩ range, the display will read 1110, from which the 10 residual is subtracted to obtain the actual resistance of 1100MΩ.

WARNING

The accuracy of the functions might be slightly affected, when exposed to a radiated electromagnetic field environment, eg, radio, telephone or similar.

Diode Tests

1. Connect the red test lead to the “VΩ” jack and the black lest lead to the “COM” jack.
2. Set the Function/Range switch to the “→I-” position.
3. Turn off power to the circuit under test.
4. Touch probes to the diode. A forward-voltage drop is about 0.6V (typical for a silicon diode).
5. Reverse probes. If the diode is good, “OL” is displayed. If the diode is shorted, “.000″ or another number is displayed.
6. If the diode is open, “OL” is displayed in both directions.
7. If the junction is measured in a circuit and a low reading is obtained with both lead connections, the junction may be shunted by a resistance of less than I kΩ. In this case the diode must be disconnected from the circuit for accurate testing.

Capacitance & Inductance Measurements

1. Set the Function/Range switch to the desired F (capacitance) or H (inductance) range.
2. Never apply an external voltage to the Cx Lx sockets. Damage to the meter may result.
3. Insert the capacitor or inductor leads directly into the Cx Lx socket.
4. Read the capacitance or inductor directly from the display.

Transistor Gain Measurements

1. Set the Function/Range switch to the desired hFE range (PNP or NPN type transistor).
2. Never apply an external voltage to the hFE sockets. Damage to the meter may result.
3. Plug the transistor directly into the hFE socket. The sockets are labeled E, B and C for emitter, base and collector.
4. Read the transistor hFE (dc gain) directly from the display.

Frequency Measurements

1. Set the Function/Range switch to the Hz position.
2. Connect the red test lead to the “VΩ” jack and the black test lead to the ”COM” jack.
3. Connect the test leads to the point of measurement and read the frequency from the display.

Duty Cycle Measurements

1. Set the Function/Range switch to the DUTY% position.
2. Connect the red test lead to the ”VΩ” jack and the black test lead to the “COM” jack.
3. Connect the test leads to the point of measurement. The display will indicate 10% to 90.0% of the frequency duly cycle.