UEEEL0020 Solve problems in low voltage a.c. circuits

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  ENROL ME IN THIS COURSE

  • Select activity Announcements

    

    Announcements Forum
  • Select activity Glossary

    

    Glossary

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  • Select activity Phasors

    

    Phasors URL

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    This website covers a lot of the content for this unit, including phasor diagrams. It will open in a new tab.

  • Select activity Equation sheet

    

    Equation sheet File

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  • Select activity Formulas

    

    Formulas Glossary

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• Select topic Alternating Current Quantities

  Alternating Current Quantities
  • Select activity Alternating current quantities quiz

    

    Alternating current quantities quiz

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    This quiz is about the ways that we measure AC current voltage and power and the different ways that we represent those values. It will also test you on Pythagoras and trigonometry because they are important tools used to understand how AC power works. Understand those and your study of this unit will be a whole lot easier. 
    

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    All those guys who figured this stuff out got to leave their mark.

  • Select activity Sine wave

    

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    Why is it a sine wave?

  • Select activity Opposition to current flow in an AC circuit

    

    Opposition to current flow in an AC circuit URL

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    There is more to it than resistance

  • Select activity Generation of AC current

    

    Generation of AC current URL

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    Why does it behave the way it does?

• Select topic Phasor Diagrams

  Phasor Diagrams
  • Select activity Phasor diagrams quiz

    

    Phasor diagrams quiz

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    Phasor diagrams help us to work out what will happen if we have several currents or voltages that are out of phase with each other. It's kind of like series-parallel circuits for AC. It would be nice if it was as simple as it is for DC but it isn't. There are conventions that are used here that most electricians in Australia use. These conventions may be a little different in other countries which makes things a little confusing. 

  • Select activity An introduction to phasor diagrams

    

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    This video explains phasor diagrams. and it comes with a printable worksheet.
    

• Select topic Single Element AC Circuits

  Single Element AC Circuits
  • Select activity Inductive Reactance. The effect of frequency

    

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    This video refers to this worksheet

  • Select activity Inductive Reactance - The effect of inductance

    

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  • Select activity The effect of frequency and capacitance on capacitive reactance

    

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  • Select activity Phase realtionship between current and voltage

    

    Phase realtionship between current and voltage URL

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  • Select activity Single Element AC Circuits Quiz

    

    Single Element AC Circuits Quiz

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• Select topic RC and RL Series Circuits

  RC and RL Series Circuits
  • Select activity RC and RL series circuits quiz

    

    RC and RL series circuits quiz

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    This quiz is about what happens when you have a capacitor or an inductor in series with a resistor.

• Select topic RLC Series Circuits

  RLC Series Circuits
  • Select activity RLC series circuits quiz

    

    RLC series circuits quiz

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    This quiz is about what happens when you have an inductor, a resistor, and a capacitor connected in series. 

• Select topic Parallel Circuits

  Parallel Circuits
  • Select activity Parallel circuits quiz

    

    Parallel circuits quiz

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    In a DC circuit, the total current is the sum of the branch currents. In an AC circuit, the total current is the phasor sum of the branch currents. Each branch can be treated as a single component branch directly across the supply.
• Select topic Power

  Power
  • Select activity Power and apparent power quiz

    

    Power and apparent power quiz

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    The current carrying capacity of the cables we run will depend on the apparent power. This quiz looks at the difference between True power Apparent power and Reactive power. 

• Select topic Power Factor Improvement

  Power Factor Improvement
  • Select activity Power factor improvement quiz

    

    Power factor improvement quiz

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    Electricity suppliers require the customer to maintain power factor within limits. This quiz is about how to figure out how to change the power factor to satisfy the supplier. Being able to do this can have significant benefits to the electrical contractor as well because less copper is required when the current is reduced. 

• Select topic Harmonics and Resonance

  Harmonics and Resonance
  • Select activity Harmonics and resonance quiz

    

    Harmonics and resonance quiz

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    Harmonics can cause serious problems for the supply grid, RCD's and lots of electronic components in a modern installation. It would be nice to know what causes it and how to deal with it. 

• Select topic Three Phase

  Three Phase
  • Select activity Three phase quiz

    

    Three phase quiz

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    What happens when you have three windings on the same alternator and they are displaced 120^o from each other?

• Select topic Three Phase Star

  Three Phase Star
  • Select activity Three phase star quiz

    

    Three phase star quiz

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    Connecting the three windings of an alternator together at one point has some big advantages when it comes to power transmission and unballanced loads.

• Select topic Three Phase Four Wire Systems

  Three Phase Four Wire Systems
  • Select activity Three phase four wire quiz

    

    Three phase four wire quiz

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    Adding a wire to the neutral point of a star-connected system allows us to maintain phase voltages by carrying out of ballance currents.

• Select topic Three phase delta-connections and Interconnected systems

  Three phase delta-connections and Interconnected systems
  • Select activity Three phase delta-connections and Interconnected systems quiz

    

    Three phase delta-connections and Interconnected systems quiz

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    What happens if we connect the start of one winding to the finish of the next so that they form a complete loop? 

• Select topic Energy and power requirements

  Energy and power requirements
  • Select activity Energy and power requirements quiz

    

    Energy and power requirements quiz

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    This quiz should be easy if you have made it this far. It's the same as power in a single phase with a bit of a twist.
• Select topic Fault loop impedance

  Fault loop impedance
  • Select activity Fault loop impedance quiz

    

    Fault loop impedance quiz

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    Just imagine a scenario where the impedance of the cables going to your load was so high that the circuit breaker didn't trip when there was a short circuit. A 20Amp "D" type circuit breaker for example requires about 250Amps to trip immediately.