Leah Ridgway

Leah Ridgway

Leah is passionate about sharing her love of engineering with anyone who’ll listen.
She's investigating how we can teach engineering better and keen to explain what engineers *actually* do.

Location Liverpool & Nottingham, UK


  • The way I usually describe it:

    Electronic Engineering is all about information, so it covers computer chips, communications systems and protocols. (This side edges towards computer science)

    Electrical Engineering is all about the big things, so it's about electricity generation and distribution, motors and moving things. (This side edges towards...

  • I'm going out for Halloween tonight dressed at Lt. Uhura - isn't life full of coincidences? :)

    LLAP James

  • Leah Ridgway made a comment

    A big thank you to everyone who's taken part in the course, providing feedback and helping each other to learn. This has been a steep learning curve for us since it's our first mooc and it's great that people have got something out of it.

    The course mentors and our e-learning team have done a great job - thanks all :)

  • We'll definitely look at doing this if we run the course again to accommodate more people's learning styles.

  • It's a "taster" so of course we're going to suggest the wonderful University of Liverpool if you wanted to go further ;)

  • Seriously though, pretty much all the moocs I've done have had info for where you can go to take the content further.

  • I live with someone who seems unable to put CDs back in their boxes and leaves them on the table *shudder*. CDs have been able to withstand this kind of behaviour better than vinyl as the smallest scratch alters the sound.

  • CDs are a bit better able to withstand damage than vinyl in my experience :)

  • I got really frustrated when Radio 4 did a "can you hear the difference in HD?" segment on You and Yours (a consumer program) - listening on the FM radio in my car meant that obviously I couldn't hear any difference and a lot of people would have been in the same situation!

  • Designing a op-amp from transistors is still used as a computer design exercise for Year 2 students at Liverpool :)

  • It's not a very practical circuit I agree, but the idea is to demonstrate how a transistor works to people who have never seen one before.

  • It's a fascinating topic, and generally when you get to degree level you can't separate out subjects into electronics/physics/chemistry like you can at school as they all feed into each other here.

  • Getting beyond 2D is so difficult. This is why I have different coloured tennis balls in my campus classes to help students remember that it's all 3D.

  • Apologies if you find my language slightly confusing. Yes, current flows through a component not across it. However I hope the bigger picture is still clear.

    We haven't covered voltage and current sources as that's beyond the introductory scope of this course (and generally the first time you introduce undergrad students to the models they grimace!)

  • Yes, it's just for scale.

  • I love going out to schools and explaining that engineers aren't all about hard hats and spanners. Even a simple thing like building a roller coaster for a marble out of paper can get kids buzzing.

    As for university classes, it varies with the styles of different lecturers - some people give great and inspiring "chalk and talk" classes, whereas I'll go for...

  • Oh my word. That is a *bad* image of me! Gormless much?

    On the other hand, that is my favourite t-shirt!

  • In the final week we talk more about where you can go from here if you want to build things on a hobby level. Hackspaces are amazing places to share ideas and get help from other people with the same passion. List of hackspaces here: http://www.hackspace.org.uk/view/Main_Page

  • I do all my own manicures ;)

  • What did you study Jeff?

  • Oooooh, I like this idea. Particularly for elderly people in rural areas who can't drive any more; it has the potential to lessen their isolation.

  • I think that's a great idea, but I do wonder how the people would respond to them, given that the BBC were reporting that people in Africa were shocked by the medical workers in protective gear!

  • We could say that Earth is the only planet in our solar system inhabited by anything other than robots (as far as we know) ;)

  • I've corrected this now, thanks for highlighting it.

  • Take off and landing are two times where a lot of variables can change and so humans are still better at handling them.

  • There are some fascinating debates going on worldwide about the laws apply to robotics - not just Asimov's Laws!

    "Should we extend Legal Rights to Social Robots?"

    And Asimov's "Three Laws of Robotics"

  • You have understood, it's low voltage as in "below" a certain threshold in practice so there is still a voltage. The circuits later on will work because we tend to use logic for control circuits rather than for delivering large amounts of electrical power.

    There's the old adage that for an electrical engineer, low voltage is anything below 50V... for an...

  • There's now a pdf download on step 4.4 :)

  • Yes, you can order logic gates with different functions. However from there it gets interesting.... It's beyond the scope of this course, but you can make all of the other logic functions by using NAND gates connected together or NOR gates connected together (known as universal gates)! There's a nice simple article here that explains this:...

  • There's now one at the start of the week to download.

  • We're looking into where it's gone. Sorry for the inconvenience

  • Have a look at this video if you want to see them working (and not working!)... it's not an easy task for Year 1 students:

  • Here's one in action!

    (It isn't a trivial task to get them working to follow the line (particularly since I was mean and set the blue line challenge) as you'll see from the video. The test day was also an example for the need to field test, as loads of these worked fine in the lab and not on the day...)

  • Soooooon! ;)

  • Yes, you've got it :)

  • Yes I could have used the other symbol set, however I went for the distinctive shapes as I think it makes learning easier if you're a beginner.

    For anyone who's interested in further reading on the rectangular symbols there's a nice chapter in Digital Design Principles and Practices here: http://www.ddpp.com/DDPP3_pdf/IEEEsyms.pdf

  • I nearly sad it! (I think I do at some point later on if it made the final cut :) )

  • Yes David, you're correct.

    Logic is a bit difficult to get your head around at first and everyone will have a slightly different way of thinking about it that works for them. That's why I've put in the truth table, circuit symbol and switch analogy to try and help out.

  • If you look at rock beds in the earth you can see magnetic "stripes" from where the north and south poles have flipped in the planets' history - it's very cool!

    (Sorry I wasn't around last week - I was all the poorly)

  • The symbol for current is I, which originates from the French phrase "intensité de courant", which means "current intensity" in English. Remember that Ampere who defined all of this was French.

    c is already used for the speed of light (from the Latin for speed "celeritas").
    C is already used for Capacitance.

  • The order's been changed, as we developed the course, this was originally week 3 - sorry for any confusion.

  • My pound shop fairy lights are definitely connected in series! I guess I got what I paid for...

  • I've kept the numbers simple so yes, the values are unrealistic. The course is attempting to keep the maths light, which is why we made this choice :)

  • Some fantastic discussions here; really interesting to read your experiences and thoughts.

  • If I get a chance this weekend I'll do a short youtube video in a little more detail :)
    The super-short version is that if you have a charged conductor, the charges will all want to repel each other so they spread as far away from each-other as they can - that means onto the surface.

    This is then the basis for how we can build capacitors that store...

  • Yes, current acts instantaneously when you switch on a light for example.

    The idea of current flowing through the resistors is a simple model to help beginners (if you are not a beginner and know more then that's fine, but imagine your knowledge at age 16 or if this is not your area of expertise) because it can be easily compared to water in pipes. This is...

  • Both of us are correct (sorry!) depends what level you look at it:

    I have used the current passing through each resistor in turn as it is a simple way of visualising and understanding the way the circuit works.

    At an atomic level the current is a bit like a circle of pipe filled with water and no exits; you turn on the tap and the water goes around and...

  • Pet hate: American engineering text books that state questions with imperial units and then the first step is converting to metric, then doing the calculation, then converting back to imperial for the final answer. Just why?!

  • Yes, assume everything is perfect at the moment, resistance is up very soon!

  • Yes, atoms are fixed within a material and it's the electrons that move.

    As a rule of thumb, if you're looking at anything larger than an electron we say that current flows from positive to negative.

  • Probably for the same reason that in the UK we haven't switched to driving on the right like the rest of Europe and most of the world; it would cause chaos when the switch first happens!

  • In a p-type material charge is carried via the "lack of an electron" which can be confusing, hence the idea of using the imaginary charge carrier of a hole.

    A lot of electrical and electronic engineers haven't looked at chemistry since age 16, so holes are used to help them understand - if you know more chemistry and/or are happy with the idea of the "lack...

  • Yep, lecture 1 of any university course - charge is on the surface of a conductor.

    However for the purposes of the course to help people understand (think of water flowing through a pipe analogy) we've simplified it.

  • Yes, you are correct. Transformer is in common use to describe "the black box" of the laptop cable but it is only part of the system.

  • I never quite "get" how people don't like wind-farms but will tolerate pylons and even telephone cables - they all alter the landscape.

    I think offshore wind does help to strike more of a balance.

    I also remember holidaying in France as a child and being amazed by their nuclear power stations - I'd only ever seen the power stations with the massive...

  • There's also a lot of research into making capacitors more efficient so they can store the energy from solar power in the day and release it later on:

  • That's fascinating :) If I had solar panels and a smart meter I think I would get a little OCD about trying to make my supply and demand balance!

  • Thanks for the link Charles - I'm going to challenge my on campus students to have a go.

    If energy costs continue to rise I think more people will consider having their own turbines/solar panels etc. however the other side of the coin is that planning rules will need to be relaxed to allow this (speaking from a UK prospective).

    Personally I'd be happy if...

  • I was living in China when the Fukushima nuclear disaster in Japan happened. The following week the news was reporting that the building of nuclear plants had been shelved and they'd build more coal powered stations instead.

    There's no easy answer, but yes, we do need to look at it on a global scale and need governments to act according to scientific...

  • We'll be talking about energy load forecasting a little bit later this week :)

  • You can think of a capacitor (a circuit component that has capacitance) as being a "fast discharge battery" so a camera flash is based around a capacitor as this can supply the power to the bulb in the time needed.

  • Plus I'm dyslexic and the meter/metre thing always trips me up (spell-check is a lifesaver!)

  • Thanks for helping out with the explanations Martti - very much appreciated.

    When making the course it was difficult to work out what we could include due to time - I wanted to include so much more.

  • Yes, "conventional" current is in the opposite direction from electron flow. The rule of thumb is that if you're not talking about current at the electron level, assume positive to negative current flow :)

  • It's great to ask the deep questions of "why is this the way it is?" and if we had more time it would be good to explore in more depth, however we have to skim the surface here so we can then use this information to make things happen.

  • Ah the centrifugal/centripetal debate - many arguments with non-scientists/engineers over this one. Jim, you are absolutely correct that it's centripetal force, but go easy on Micheal :)

  • I think that would be great to add if we get to develop the course more in future.

  • Nuclear is always controversial and has a lot of emotions attached to people's views of it. Sellafield is not too far from Liverpool and they spend a lot of research energy into the safe storage of waste - if we could solve that problem for good then I think nuclear would have a lot more support.

    One of my friends once said "Homer Simpson has a lot to...

  • That's a great topic, but it's beyond the scope of what we'll cover here. The "chips" in modern car keys make the whole system a lot more secure than traditional keys.

  • I have been known to press the button and pretend I'm a wizard as the car unlocks ;)

  • But if we know how those components interact we can "see" how it does all go together :)

    A lot of basic electronics can be explained using mechanical analogies which can help our understanding.

  • The course is aimed at anyone aged 16+ so you might find some of the topics simplified. It's a taster, but please, feel free to discuss in more depth in the comments :)

  • Sorry all, we're tied into the format by Futurelearn. I will find out if there's anything we can do to improve the transcripts.

  • Thank you!
    It's interesting to see how attitudes towards people having piercings and tattoos have really changed over the last 10 years. It's fantastic to work in a field where I'm judged on my ability and not on my appearance.

  • Leah Ridgway made a comment

    Welcome everyone :) So excited to be getting started - we've been working on the course for months in the background. Hope you enjoy it and learn something too