INTRODUCTION TO BASIC ELECTRONICS

BE-6: Identify and Use Zener Diodes

Overview:

Identify zener diodes.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Identify zener diodes.”

Whilst learning towards the outcome you will be required to achieve the following:

  • Identify zener voltages.
  • State in which direction a zener diode is connected in a circuit to act as a voltage regulator.
  • Draw the circuit symbol for a zener diode.
  • Draw a curve of the forward voltage (VF) against current (IF) for a zener diode.
  • State the reasons why a series resistor (RS) is connected in a zener parallel voltage regulated circuit.
  • Draw a characteristic curve for zener voltage (VZ) against current (IZ) for a zener diode.
  • Draw a IZ/VZ characteristic curve for the operating range of a zener diode and show all the calculations made.
  • Draw a circuit diagram showing how different voltages may be obtained from a common supply by means of zener diodes.
  • State what the effect would be if zener diodes were connected in series.
  • State what the effect would be if zener diodes were connected in parallel.
  • Draw a waveform indicating peak voltage, when the voltage is “clamped” with zener diodes.

Tools, consumables, machinery and equipment required:

  • Small sidecutters
  • Soldering iron
  • Soldering wire
  • Oscilloscope
  • Multimeter
  • Resistors (100 Ohm ½ W, 1K ohm ½ W, 2 x 150Ω ½ W, 10K, 4K7, 2K2, 1K, 470Ω, 330Ω, 220Ω).
  • Variable AC supply
  • Variable DC supply
  • Zener diodes (5V 1W, 7.5V, 9V, 10V 1W, )
  • 1N4007 diodes
  • Bridge Rectifier (50V 1A)
  • 2200 uF Electrolytic capacitor
  • Circuit board
  • Connecting wires
  • De-soldering pump

Related modules:

  • BE-4
  • BE-5
  • BE-10

Application:

  • Zener diodes are used as voltage and shunt regulators.

Additional resources

  • Electrical Technology Edward Hughes.

Pages 578 and 579.

  • Electrical Trade Theory C. du Preez.

Page 181.

  • Semi-conductor Reference Book.

TI-2: Use and Care for an Oscilloscope

Overview:

Use an Oscilloscope.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Use an oscilloscope.”

Whilst learning towards the outcome you will be required to achieve the following:

  • Set up an oscilloscope for practical application in accordance with the oscilloscope manual.
  • Measure periods from the cycles on the screen of the oscilloscope to obtain frequency.
  • Measure AC and DC voltages, peak-to-peak values and calculate RMS voltage values from measured results.

Tools, consumables, machinery and equipment required:

  • Resistors ( 1K Ohm, 4.7K Ohm, 10K Ohm, 470 Ohm)
  • Capacitors (4.7uF/10 uF)
  • 741 Operational amplifier
  • Oscilloscope
  • Sound sensor
  • Function generator
  • AC supply
  • DC supply

Application:

  • An oscilloscope is a lab instrument that is used to measure electrical waveforms.

Additional resources

  • Manufacturers and Suppliers Specifications
  • In-company Standard Operating Procedures
  • In-company documentation
  • Operating drawings and schematic diagrams

BE-5: Construct a Rectification Circuit

Overview:

Construct a rectification circuit.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Construct a rectification circuit.”

Whilst learning towards the outcome you will be required to achieve the following:

  • Draw the circuit diagram for a half wave rectifier, a full wave rectifier with a centre-tap transformer and a full wave bridge rectifier.
  • Construct a rectification circuit.
  • Display the waveform on an oscilloscope
  • Draw half wave and full wave rectified waveforms.
  • Measure and calculate the mean (average) DC voltage of a half wave and a full wave rectifier.
  • Draw a waveform for a smoothed rectified circuit without load.
  • Draw a waveform for a smoothed rectified circuit with a load.
  • State the reason for a smoothed rectified circuit having a higher voltage than an unsmoothed circuit.

Tools, consumables, machinery and equipment required:

  • Oscilloscope
  • AC Supply
  • 1N4007 silicon Diodes (9)
  • Single pole single throw switch
  • Multimeter
  • 24V 3W lamp (2)
  • Circuit board
  • Connecting wires
  • 12V lamp (3)
  • Bridge rectifier (50V 1A)
  • 1000 uF 16V+ capacitor
  • Soldering iron
  • Soldering wire
  • Small sidecutters
  • De-soldering pump

Related modules:

  • BE-4
  • BE-6
  • BE-10

Application:

  • Rectification circuits take an AC input and rectify it to a DC output.

Additional resources

  • Electrical Trade Theory C. du Preez

Pages 179 – 180.

BE-4: Identify and Use Diodes

Overview:

Identify diodes.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Identify diodes.”

Whilst learning towards the outcome you will be required to achieve the following:

  • Identify the diode characteristics (peak inverse voltage and maximum current).
  • Distinguish between the cathode and anode of a diode.
  • State to which polarity of the supply the cathode is connected when the diode is forward biased.
  • Draw the circuit symbol for a diode.
  • Give the letter symbols for a cathode and anode of a diode.
  • Describe how diodes are identified.
  • State in which direction a diode is biased when it conducts.
  • State the two voltages which equal the supply voltage (VS) when a diode is forward biased.
  • Name two types of diodes.

Tools, consumables, machinery and equipment required:

  • 12V DC supply
  • 12V Lamp
  • Single pole single throw switch
  • 1N4007 (1A, PIV 1000V) Diode
  • Circuit board
  • Connecting wires
  • Multimeter
  • Soldering iron
  • Soldering wire
  • Small sidecutters
  • De-soldering pump

Related modules:

  • BE-5
  • BE-6
  • BE-10

Application:

  • Bridge Rectifiers
  • Signal limiters, modulators, demodulators, mixers
  • Voltage regulators
  • Switches
  • Oscillators

Additional resources

  • Display board
  • Electrical Trade Theory C. du Preez

Pages 177-179

  • Electrical Technology Edward Hughes

Pages 565-578

  • Semiconductor Reference Book
  • Diode Identification Chart.

BE-3: Identify and Use Inductors

Overview:

Identify and use inductors.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Identify and use inductors.”

Whilst learning towards the outcome you will be required to achieve the following:

  • Identify types of inductors.
  • State what “change” an inductor resists.
  • State whether an inductor offers high or low resistance to current flow in an AC and in a DC circuit.
  • State the name of an inductor resistance to AC current.
  • State the unit of induction.
  • Name two smaller units of induction.
  • Give the symbol for a coil (inductor).
  • Name the two main types of induction coils and draw their circuit symbols.
  • Give the quantity symbol for impedance and its unit.
  • Give the quantity symbol for inductive reactance and its unit.
  • Explain in your own words how an inductor affects a DC and an AC circuit.
  • Calculate the total inductance of inductors in series and parallel.
  • State the sequence of events when the DC current through a coil is interrupted.

Tools, consumables, machinery and equipment required:

  • 12V AC supply
  • 12V DC supply
  • Multimeter
  • Ohmmeter
  • Inductors (5H (3))
  • Resistors as required.
  • Single pole double throw switch
  • Single pole single throw switch
  • Connecting wires
  • Circuit boards
  • Soldering iron
  • Soldering wire
  • Small sidecutters
  • De-soldering pump

Application:

  • Inductors can be used to block AC current while allowing DC current to pass.
  • They can be used in electronic filters, in aid to build tuned circuits, and used to tune radio and TV receivers.

Additional resources

  • Basic Electricity van Valkenburgh, Nooger
  • Part 3, and Neville Inc.
  • pages 3.43 to 3.52,
  • 3.67 to 3.70.

BE-2: Identify and Use Capacitors

Overview:

Identify and use capacitors.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Identify and use capacitors.”

Whilst learning towards the outcome you will be required to achieve the following:

  • Identify 6 different types of capacitors.
  • Give the abbreviations and the value in farads of :
  • (a) Microfarad,
  • (b) Picofarad,
  • (c) Nanofarad.
  • Decode a capacitor using the colour code chart.
  • Calculate the time constant of a RC time delay circuit.
  • Calculate the total capacitance of capacitors connected in series and in parallel.

Tools, consumables, machinery and equipment required:

  • Electrolytic capacitors (100 μF 25 V (1), 1000uF 25V (1), 47 uF 63V (3), 100 uF 63V (1))
  • Multimeter
  • 12V DC supply.
  • 12V AC supply.
  • Circuit boards.
  • 3x single pole with a single throw (SPST) toggle switch.
  • Connecting wires.
  • Resistors (4K7(1), 10K (1))
  • 4x 12V Filament lamps.
  • Soldering iron
  • Soldering wire
  • Small sidecutters
  • De-soldering pump

Related modules:

  • Most electronic modules (BE-3 to BE-12)

Application:

  • Capacitors are components that store electrical charge.

Additional resources

  • Basic Electricity van Valkenburgh, Nooger Part 3, Pages 3.75 and Neville Inc.to 3.118.
  • Electrical Technology Edward Hughes. (Pages 143-150.)

BE-1: Identify and Use Resistors

Overview:

Identify and use resistors.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Identify and use resistors.”

Whilst learning towards the outcome you will be required to achieve the following:

  • Identify types of resistors and their wattage rating.
  • Name two types of variable resistors, draw their circuit symbols and state what they can control.
  • Decode resistors from their coloured bands.
  • Determine the value of a resistor with a test instrument.
  • Determine the value of resistors in parallel by calculation and by measurement with a test instrument.
  • Determine the value of resistors in series by calculation and by measurement with a test instrument.
  • Determine by measurement and calculation, voltages and currents over resistors of different values connected in series.

Tools, consumables, machinery and equipment required:

  • Multimeter
  • Resistors (100 Ohm 0.5W, 150 Ohm 0.5W)
  • Circuit board
  • Connecting wires
  • Potentiometer
  • Lamp
  • Soldering iron
  • Soldering wire
  • Small sidecutters
  • De-soldering pump

Related modules:

  • Most electronic modules (BE-2 to BE-12)

Application:

  • Resistors are used to slow down the current in a circuit.

Additional resources

  • Display Boards.

HM-3: Solder Components

Overview:

Solder Components.

Key and critical concepts which you will learn:

  • You will be learning towards the outcome “Soldering components.”

Whilst learning towards the outcome you will be required to achieve the following:

  • When soldering you should meet the following requirements:
  • The wires must protrude +/- 1 mm above the copper track.
  • The solder fillet must cover the land evenly and taper up to blend into the wire in a concave shape.
  • The solder fillet must have a height of at least 0,75mm above the copper track.
  • The copper strip must not be lifted off the track (due to overheating).

Tools, consumables, machinery and equipment required:

  • Soldering Iron.
  • Soldering Wire.
  • Circuit Board.
  • Side cutter.
  • De-soldering Tool.
  • Various Components/Wires.

Related modules:

  • All modules that require soldering.

Application:

  • Solder circuit boards.
  • Solder wires to studs, pins, terminals, etc.

Additional resources

  • Electrical Trade Theory – C.du Preez (Pages 21-25).
  • Display Boards.