Strong Wind Measurement

Lesson 4: Hurricanes and Typhoons

Theory:

Hurricanes, Typhoons, and Cyclones are formed when moist air evaporated over warm seas is pushed high into the air and becomes a vortex when it comes into contact with cooler winds. Tornadoes and Twisters form over land when warm air and cold air collide. Hurricanes turn anti-clockwise in the northern hemisphere, Cyclones turn clockwise in the southern hemisphere. Most of all, these are high-wind speed disasters that commonly cause flooding, property damage, and loss of life.

Motors and Generators:

Motors:

An electric motor is a device that takes in electricity and uses it to rotate an axle. Inside a motor has coil of copper wire wrapped tightly together, and a magnet surrounding it.

Electricity and magnetism are closely linked in the world of science, particularly physics. When electricity is conducted through a wire, a very small magnetic field is generated. When the copper coil has current passed through, the coiling of the wire concentrates the magnetic field into one big magnetic field, strong enough to repel against the magnet surrounding it, causing it to begin to spin, just like when you bring two north or south poles of a magnet together, they repel.

Generators:

An electric generator is exactly the same as an electric motor, but instead of using electricity to generate motion, you use motion to generate electricity!

Remember earlier we said electricity and magnetism are linked? Spinning the coil against the magnet will generate electricity in the coil! That’s how wind turbines, steam based generators and water based generators (like ones attached to waterfalls) work.

https://cdn4.explainthatstuff.com/how-electric-motor-works-animation.gif

Practical:

In this lesson we will be detecting hurricanes by using the motion of the generator to generate electricity that can be read by our microbit.

Just like in lesson 1, we will be using the “0” pin to detect the generated electricity when our motor spins.

To wire up our circuit for this lesson have one wire leading from one “leg” of the motor to the GND (Ground) pin of our micro-bit, and the other “leg” connected to the “0” pin.

Our code this lesson will be as such:

1. We will need the forever loop block to have our microbit constantly on the lookout for a cyclone. (Forever loop block located in Basic)
2. We will need to READ how much electricity is running into our “0” pin, to do this, click advanced -> pins -> analog read pin “0”

3. We will need to compare this value with a set limit that will tell us how fast the generator is spinning. To do this we will use our CONDITIONAL blocks “IF <something> THEN” and the “GREATER THAN” block (These are located in Logic)

4. We have put the value 300 in there, but depending on your motor, you may need to change this to something higher or lower. Higher values will mean that you need to spin the motor FASTER for the code inside the “IF THEN” block to run.

5. We will need to add an output so that we can tell if the generator is spinning fast enough.

6. To tell finer differences between simply a light wind and a cyclone, you can add extra conditional blocks (IF THEN), with different values.

Extension / Questions:

1. Could I also use the radio to send a warning signal to another microbit?
2. How could I use the motor as a motor instead of a generator? Hint: Use another pin OTHER than pin 0, (maybe something that is always giving out power?)
3. What other devices do you know about that use a generator or a motor?
   1. Remote controlled car?
   2. Wind-up torch
   3. Electric car, Tesla?