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3.0 - Electromagnetic switch

Students will use Electromagnetic Signals to activate and control remote device(s) and activate a remote device/switch:

  1. Two radio controlled systems (RC cars) and two programmable devices (Bee-bots) will be allocated to each group.
  2. Each group must refer to the Magic Radio Controlled Car FIXME instructions as they follow the steps below:


Students will be allocated with two remote control Bumper cars and two programmable Bee-Bots

Two of the groups will be provided with one Radio Controlled bumper car each.

  1. Check the blue and red dot labels on the car and controller to make sure they match (red car to red dor controller, blue car to blue dot controller. The cars must be moved using remote control only - students must not push or touch the Bumper cars to move/steer them

Two groups will be allocated one Bee-bot each. The Bee-bots are controlled by entering data on the Bee-bot keypad - students must not push or touch the Bee-bots to move/steer them

Your mission (should you choose to accept it), is to complete one simple task (the 'headlight' task) and then drive your car/Bee-bot to the finish line. The group who takes the least amount of time will win the challenge (you must record your start and finish time(your teacher will show you the location of the “Finish Line” for your team. - you are not allowed to touch or move the car/Bee-bot except by using the controller/Bee-bot keypad)

Each group will attach a torch to their car/Bee-bot and then navigate a course with the headlight turned ON - This is referred to as 'The Headlight Task'

What you have to do:

  1. Write down your starting time.
  2. Use the controller/Bee-bot keypad entries, to drive the car and to complete the 'headlight' task. When the headlight task is completed, drive your car/Bee-bot to the finish line.

Bumper car Instructions

The magic controller (Bee-bot groups should jump straight to the 'Bee-Bot Instructions' section

  1. This section is for the Bumper car groups ONLY: Before you can drive your car, you must use some magic to make the controller work - Use a magic wand (supplied by your teacher) to make the controller work. The magic wand uses switch technology that you have already learned about, but you must use all of your cunning to solve the riddle and to switch the controller ON (no spell is required - only care and your wits).
  2. HINT 1 - Wave your wand slowly and cover all of the angles… while watching the LED on the controller!
  3. HINT 2 - You will need to work co-operatively to use the magic want and the controller together… Only the driver should watch where they are going…
  4. HINT 3 - Before you start, have a group planning session to discuss how you are going to perform the challenge and guess how you think the magic wand may work. Don't forget that you must work out how to make the magic work while you drive - If you want to stand a chance of winning, do not tell people in the other groups how to do that!

Get started - Finding the Magic Switch

  1. Move the switch on the RC hand controller to the 'ON“ position - notice that the LED above the switch remains OFF.
  2. To find the 'magic' switch and turn on the RC controller, reflect about what you have learned about switches in the earlier activities. When your wand activates the magic switch, the LED on the controller will turn ON and you will be able to drive the car using the FORWARD, BACK, LEFT and RIGHT arrow buttons on the controller
    1. HINT: To drive the car most easily, just press and release the controls for short bursts instead of holding the buttons down continuously.
Magic Switch: A reed switch is added & concealed(1,2) Magnet is glued to wand(3,4) Hold wand/magnet over handle to activate(4)
Magic Switch Howto
Magic Switch: Use the wand to activate the magic switch on controller

Bee-bot Instructions

You will need to drive your Bee-bot by entering a sequence of commands via the Bee-bot keypad. You may make multiple entries any time you like - you do not have to go back to the start if you make a mistake - just carry on from where you are. You are not allowed to push or position the Bee-bot with any part of your body.


The Headlight Task

Your first task will be to set up the night-light using the black paper light shield (as per activity done yesterday).

  1. When you have set up the night-light, attach the torch to yout Bumper car/Bee-bot using Blu-Tack, masking tape and/or rubber bands
  2. Position your car headlight/torch at a night light so that your headlight turns the night-light OFF.

First,test that you can drive the car using remote controller and that the night-light is ON and the night-light is shining.

For Bumper car groups:

Do not proceed until you have found out how to use your magic wand and that you can drive the Bumper car using remote control (remember the HINTS above):

For Bumper car and Bee-bot Groups:

Attach your test light/torch to the front of an RC car/Bee-bot using Blu-Tack, Plasticene, rubber band(s) or similar (so that the lED is pointing forward like a car headlight - see image)

  1. Press the push-button on the base of your torch to turn on LED torch/'headlight' attached to car.
    1. Make sure torch is reliably fixed to car/Beebot and that torch is turned ON
    2. Enter the time in you results sheet

For the nest section, you must not touch the car to move it - you must only position it using the Bee-bot keys or Bumper car radio control system (or request permission from your teacher first if you really think you need to move it manually).

  1. Drive and position the car/Bee-bot so that its headlight shines into the opening in the black paper shade attached to your night-light.
    1. When you shine your torch/headlight into the opening. the lamp on the night light should turn OFF
      1. Turn the car/Bee-bot away from the night-light (so that headlight stops shining on night-light): The night light should turn ON.
      2. Measure the maximum distance from the night light to the car headlight to switch the night-light from ON to OFF
      3. Record the distance in the results table and any observations in the 'comments' section.
Attach LED Torch using Blu-Tack/Rubber Band/Masking tape
LED Torch as Headlight

After recording your results, drive your Bumper car/Bee-bot to the Finish line and record your finishing time. Ask someone in another group to sign and print their name against your results (to verify that you have entered the correct finish time)

If you have time left over, let someone else in your group try using the magic wand and controller.

learn/circuits/example-activities/switch-electromagnetic/home.txt · Last modified: 17/07/2017/ 10:53 by