TESTS

Test Logic Gates

Module: IE-6

Overview:

Test logic gates.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Test logic gates.”
  • Whilst learning towards the outcome you will be required to achieve the following:
    • Test and determine the switching state to obtain a “1” at the output of a logic circuit.
    • Name four different logic families.
    • State what supply voltage may be applied to a complementary metal oxide semi-conductor (CMOS) device.
    • State four precautions that must be taken when handling CMOS devices.
    • Draw the circuit symbols for an AND, OR, NAND and NOR gate.
    • State the difference in truth tables for the following:
      • AND gate and NAND gate.
      • OR gate and NOR gate.
    • Draw the equivalent electrical circuit for each of the following gates:
      • NOR gate.
      • NAND gate
      • OR gate.
      • AND gate.
    • Name two advantages of CMOS devices over other devices.
    • State what a 1 and a 0 is equal to in positive logic.

Tools, consumables, machinery and equipment required:

  • Oscilloscope
  • Circuit board
  • Connecting wires
  • Soldering iron
  • Soldering wire
  • Small side cutters
  • De-soldering pump
  • Anti-static wrist strap
  • Dual 10V DC supply
  • N-channel JFET
  • Potentiometer (5K)
  • Multimeter
  • Resistors (10K, 1K)

Application:

Applications will depend on the logic gate in question but to name a few; alarm systems, bell switches, temperature detection, etc.

Additional resources

  • Display Board
  • Data chart

Test Field Effect Transistor

Module: IE-5

Overview:

Test a field effect transistor.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Test a field effect transistor.”
  • Whilst learning towards the outcome you will be required to achieve the following:
    • Test and determine what the voltage and current is on the gate of a field effect transistor when it is both conducting and not conducting.
    • Give the abbreviation for a field effect transistor.
    • State whether the field effect transistor is controlled by current or by voltage.
    • State the normally off or on conditions of the depletion and enhancement field effect transistors.
    • Give the abbreviation for a junction field effect transistor.
    • Give the abbreviation for a metal-oxide semi-conductor field effect transistor.
    • Name the three connections of a junction field effect transistor.
    • Draw the circuit symbols for n-channel, p-gate and p- channel, n-gate junction field effect transistors.
    • State whether the input impedance of a field effect transistor is high or low.

Tools, consumables, machinery and equipment required:

  • Oscilloscope
  • Circuit board
  • Connecting wires
  • Soldering iron
  • Soldering wire
  • Small side cutters
  • De-soldering pump
  • Anti-static wrist strap
  • Dual 10V DC supply
  • N-channel JFET
  • Potentiometer (5K)
  • Multimeter
  • Resistors (10K, 1K)

Related modules:

  • BE-8
  • BE-9
  • IE-1
  • IE-2

Application:

Used as input amplifiers in oscilloscopes, voltmeters, and other measuring/testing equipment.

Additional resources

  • Display Board
  • Data chart

Test Multivibrators

Module: IE-3

Overview:

Test multivibrators.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Test multivibrators.”
  • Whilst learning towards the outcome you will be required to achieve the following:
    • Test and determine types of multivibrators.
    • State which multivibrator is stable in one state, which is stable in two states, and which is not stable.
    • Draw the output waveform of an astable multivibrator and indicate the periods that the transistor is in saturation and cut-off modes.
    • State the equation for the DC time factor for an a-stable multivibrator circuit.
    • Give another name for a flip-flop circuit.
    • State which multivibrator has a memory.
    • State the two triggering methods used to change the state of a flip-flop circuit.
    • State the name of the diodes in a bi-stable frequency divider circuit.
    • State how many input cycles are necessary for one output cycle in a frequency divider?
    • State two other names for a mono-stable circuit.
    • State the name of a circuit that may be used to square sinusoidal inputs.
    • State why the emitter voltage has to be approximately 0,6 volts lower than the input voltage of a Schmitt trigger before it will switch.
    • State what waveform will appear at the output of a Schmitt trigger if a triangular wave is applied to the input.

Tools, consumables, machinery and equipment required:

  • Oscilloscope
  • NPN Transistors
  • DC supply (10V,
  • Resistors (15K, 390, 10K, 1K, 4K7, 150K, 2K2, 22K)
  • Circuit boards
  • Connecting wires
  • Single pole double throw switch
  • Light emitting diodes (LED’s)
  • Capacitors (100uF, 47uF, 10nF, 8uF, 1nF)
  • 1N4007 diode
  • Single pole single throw switch
  • Potentiometers (10K, 1K)
  • Multimeter

Related modules:

  • IE-2

Application:

Used in devices such as relaxation oscillators, timers and flip-flops.

Additional resources

  • Display Board
  • Data chart

Test an Amplifier

Module: IE-1

Overview:

Test an amplifier.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Test an amplifier.”
  • Whilst learning towards the outcome you will be required to achieve the following:
    • Test an amplifier circuit with an oscilloscope.
    • Determine the voltage gain after each stage.
    • State the purpose of an amplifier
    • Explain what a transistor amplifies.
    • State what the configurations of transistors are shown in a diagram.
    • State what the input and output impedances are for different configurations.
    • Explain the reason for using a specific output impedance for an amplifier output.
    • State whether a specific transistor configuration will amplify voltage.

Tools, consumables, machinery and equipment required:

  • Oscilloscope
  • Circuit board
  • . Connecting wires
  • 10V DC supply
  • Signal generator
  • NPN Transistors (2N2219 or equivalent)
  • Loudspeaker (8 Ohm impedance)
  • Resistors
  • Electrolytic capacitors (47 uF 16V)
  • Polyester capacitor (0.1 uF)
  • Soldering iron
  • Soldering wire
  • De-soldering pump

Related modules:

  • BE-8
  • BE-9
  • IE-5

Application:

The purpose of an amplifier is to take a very small signal, i.e. one that is so small that it cannot be used, and amplify it many times so that it can be used elsewhere, e.g. to drive a loudspeaker, or be seen on an oscilloscope, or operate a motor, etc.

Additional resources

  • Display Board
  • Data chart

Test a Three Phase Installation

Module:  IT-2

Overview:

 In this module you will be taught how to test a three phase installation  

Key and critical concepts which you will learn:

  • Carry out a continuity resistance test on conductors.
  • Carry out a cable ratings test.
  • Carry out a switch gear ratings test.
  • Carry out an insulation resistance test between conductors.
  • Carry out an insulation resistance test between conductors and earth.
  • Carry out an earth leakage relay test.
  • Carry out an earth continuity resistance test.
  • Carry out a mechanical test.
  • Comply with requirements of the hazard identification and control (HIAC) form.

Tools, consumables, machinery and equipment required:

  • A Fully wired three phase installation
  • Testing instruments – Insulation resistance tester, multimeter, earth leakage tester
  • SANS 10142-1 code of practise
  • A prescribed form for recording of readings

Related modules:

  • IT-1
  • CT-1

Application:

  • The three phase installation can be used wherever you need to supply a load and which must be protected with switchgear, circuit breakers overloads etc  

Additional resources

  • Subject matter experts
  • In-company Standard Operating Procedures