Lesson video

Hello, thank you for joining me for your Design and technology lesson.

My name is Mrs. Conway and I will be guiding you through your learning today.

So today's lesson outcome is, I can explain how pneumatic systems work.

And these are our keywords, pneumatic system, input, and output.

I'll go through each one of these as we work through the lesson.

So the first thing we're going to look at then are pneumatic systems - input and output.

There are lots of products that use air to work.

And some systems that use air are called pneumatic systems. Pneumatic systems force air into an object to change its shape or make it move.

You may have heard the whoosh sound of the air opening a train, bus, or tram door before.

Now systems often have an input and an output.

An input is something that goes into the system.

For example, if you move the joystick on a games controller, this sends a message to the computer, so you're giving it an input.

Here you've got that example of that joystick, and the input might just be moving the little joystick part around on the games controller.

The output is what happens as a result of the input.

So in this example, the output is the character in the game moves.

Now a pneumatic system is a mechanism that uses moving air to make things happen.

Air goes into the system and this is the input.

The air can come from natural air like the wind, forced air like from a pump, so a pump that you would buy pump up a bicycle tyre with for example, or blown air, which comes from our lungs.

So if you're blowing up a balloon with your lungs, (blows) with your blowing into it.

The moving air causes something to happen, and this is the output.

Quick check for understanding on all of that then.

Which part of the system is what happens as a result of the moving air? Is it A, input.

B, output.

Or C, wind.

Pause the video just to take a moment to think about your answer.

And the correct answer, it was B, output.

So the part of the system is what happens as a result of the moving air is the output.

Well done if you got that right.

So let's look at a simple pneumatic system.

So here we have a bottle.

This is a plastic bottle that is full of air.

Now as that bottle is squeezed, that's causing the input, and that's pushing out the air from inside that bottle.

Now the air is then forced or pushed along that plastic tubing, and it eventually goes along to a balloon, and the balloon then inflates and as it inflates, that is the output.

Let's look at another example of a simple pneumatic system.

So in this example, we have a plunger or a syringe.

Now the air is sucked in and then pushed out by the plunger, and this is the input.

Now that air is once again being forced through that tubing and it could be being forced backwards or forwards.

The output in this then is the air moving along and moving the plunger in or out and that is the output.

Let's look at one more simple pneumatic system then, and this again is using the plunges or the syringes, but this time we have a Y connector.

And the Y connector is allowing more than one output.

So again, air is sucked in and pushed out by the plunger, and that is the input.

It's pushed along the tubing, but this time it's split into two paths using that Y connector, and then the moving air moves the plungers in and out, and that is our output.

But in this example, we have two outputs.

Right, let's have a look at a question then.

Who is describing how this simple system works? So you've got the picture of the simple system there.

Is it A, Alex.

B, Sam.

Or C, Izzy.

Let's have a little look at how they're explaining the system.

So Alex has said air is forced backwards and forwards along the tube causing the single output syringe to move in and out.

Sam has said air is forced along the tube and into the balloon causing it to inflate, and Izzy has said air is forced along the tube, split into two paths by the connector affecting both outputs.

Have a really close look at that picture and have a big, think about this pause the video here to have a go And the correct answer.

It is C, it's Izzy who's describing this correctly.

So you can see there this system has a Y connector, so air is forced along the tube, split into two paths by that connector affecting both outputs, so two outputs there.

Well done if got that right.

Now, simple pneumatic systems can be used to create movement in a moving animal toy, just like the lovely examples you've got here.

Now they can create a lifting movement, movement in and out, or up and down.

Alex is explaining how this toy creates movement using a simple pneumatic system.

So he's explained, "Air is squeezed out of the bottle.

And you can see that in the diagram with our input.

It is forced along the tube to the balloon.

It fills the balloon, which inflates and expands lifting the top jaw of the crocodile toy." And that is causing our output.

Okay, over to you then to have a go at a task.

I'd like you to label the input and output of these three pneumatic systems. I'd then like you to choose one of the systems. Can you explain how it would create movement in a moving toy? Now, to do this, you can use some of these words, input, output, inflate, expand, air, split, move, and increase.

Now, you do not have to use all of those words, just see if they will help you to explain and answer the question.

Okay, pause the video here to have a go at these two tasks and good luck.

How did you get on? Let's have a look at our first task.

I asked you to label the input and output on these pneumatic systems. So just compare your answers to the ones I'm showing you here and check that you've got those right.

Alex has said, "Only systems with a connector should have more than one output." So just double check that in your answers as well.

The second part of the task then, you should have included something like these points in your explanation.

So if you picked this particular pneumatic system, you should have included these kind of points by squeezing the bottle, air is sucked in.

The air is forced or pushed along the tube, the balloon inflates.

Just check your answer and see if you've got those key points included.

If you pick this pneumatic system, you should have these key points.

Air is sucked in and pushed out by the plunger.

Air is forced backwards and forwards.

The plunger moves in and out.

And if you picked this example, you should have these key points.

Air is sucked in and pushed out by the plunger.

Air is pushed along the tubing and split into two paths, and the air moves the plungers in and out.

Again, just check your answer against that and see if you've got those key points included.

Okay, next we're going to look at changing pneumatic systems. Now we have learned how simple pneumatic systems use air to change the shape of an output or make it move.

We've also learned that like other systems, pneumatic systems have an input and an output.

Now, Alex has just asked a question here, "What is the difference between input and output?" Can you explain that? Pause the video here.

Just have a little think about that question.

The input is something that goes into the system.

In this case it's air, and this air can be from wind, pumps, or our lungs.

The output is what happens as a result of the air being forced or directed through the system.

Now this could be movement or changing shape or size, such as inflating and expanding.

Now, when we make a simple pneumatic system, we can think about the size of each component or part, and how it affects the whole system.

Now, if we look at these examples, what might happen if we use a larger bottle, for example? If we use a larger bottle for the input of this pneumatic toy, would there be any difference? Again, pause the video just to think about that question.

The larger bottle would hold more air, so we would be able to force more air into the balloon with each squeeze.

Okay, so what effect would that have on the balloon? Again, pause the video just to have a little think about that question.

Now, because the bottle is larger, we can force more air into the balloon with each squeeze.

That means the balloon would inflate quicker because more air is being pushed into it each time.

Okay, quick question for you then.

Why would a larger bottle inflate the balloon quicker? Is it A, there's more air forced in with each squeeze.

B, it's easier to hold.

Or C, there's less air moving along the tube with each squeeze.

Pause the video here just to have a think about your answer.

And the correct answer was A, the larger bottle would inflate the balloon quicker because more air is forced in with each squeeze.

Well done if you got that right.

Now, Alex here is wondering what would happen if a small, so 10 mil syringe was used as the input in this system, but the output was a larger 20 mil syringe, and he suggested, "I think it would be harder to move the output syringe because the input would only move a small amount of air.

It might take longer." What do you think? Pause the video if you'd like to take a moment just to think about that.

The changes we make to the components of our own moving animal toy could affect the speed of the movement, but also the size of the movement.

Now, Alex has said, I want the jaws of the crocodile to open and close quickly to make it look like it's snapping.

So what could I change? Have you got any ideas? Again pause the video here.

Just have a little think.

Are there any things that Alex could change here to help him with his moving toy? So here's some ideas.

To make the jaws open and close quickly, Alex needs to get as much air into the balloon as he can with each squeeze of the bottle.

So Alex could change the size or the type of bottle, the length of the tubing, and also the shape of the balloon.

Did you come up with those ideas? Okay, let's do a quick check then.

True or false.

Increasing the size of the input bottle would create a bigger movement in the output balloon.

Is that true or false? Pause the video here to have a think about your answer.

And the correct answer is true.

So increasing the size of the input bottle would create a bigger movement in the output balloon.

And the reason for that is the largely input, the more air it can move with each squeeze, and this will cause the output to make a larger movement.

So well done if you got that right.

Okay, it's going to be over to you now to have a go at some more tasks.

I'd like you to set up a simple pneumatic system by connecting two syringes with a length of tubing.

And I'd like you to extend, explore what happens when you change the sizes of the syringes.

So I asked you this question earlier when Alex suggested his idea of what might happen.

This is your chance to explore and try this out for yourself.

Have a little think.

What happens if you change the length of the tubing as well.

The second task, I'd like you to then add a three-way connector and another syringe to create two outputs.

Again, I'd then like you to explore what happens when you change the sizes of the syringes.

And again, consider what happens if you change the length of the tubing.

And the last task I'd like you to then do would be to consider your own ideas for a pneumatic animal toy.

Think about these questions.

What type of system would create the movement? And what size, and shape components would you lead? Okay, quite a few tasks there and some really fun exploring to be done.

So pause the video here and good luck.

Okay, how did you get on? Hopefully you enjoyed that exploring with the different pneumatic systems and what happened when you changed the components.

Alex has just explained what he saw as he was doing that.

When we used a smaller syringe for the input, it was harder to get the air to fill the output syringe.

It took longer.

And he did suggest that that might happen.

Sam has said, "When we added longer piece of tubing, it also took longer to get the air to affect the output and we had to use the larger syringe." Now, I asked you to explore the different pneumatic systems and hopefully you came up with your own results and were able to see what happened when you changed the components.

Hopefully, you've got some lovely creative ideas as well for your own moving animal toy of how you might create different movements.

Okay, let's summarise today's lesson then.

Today we've been looking at exploring pneumatic systems. And the key points from this lesson are, pneumatic systems use air to work, the air inside the bottle, which is the input forces air into the balloon, which is the output, which then expands.

Air inside one syringe, the input is forced through the plastic tubing into the other syringe, which is the output which expands.

And if one syringe is a different size to the other, the amount of air in the syringes affects the movement.

Well done for all of your hard work today.

I hope you've enjoyed today's lesson and I will see you soon.