TriColour LED Flashlight

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Make your own TriColour LED Flashlight!

Big Ideas: 
  • Switches are used in electronic circuits so the user can easily create and break closed loops.
  • LED flashlights can provide plenty of light using only a small power source.
  • Addition of primary colours to produce secondary colours and white light.

Purpose

This simple TriColour LED flashlight has been used as an activity for our summer camps to illustrate current electricity and circuits. The concept of "completing the circuit" is easily explained by closing the different switches and creating closed loops, activating the appropriate LED colours. You can have different combinations of closed switches to have your flashlight shine red, blue, green, magenta, cyan, yellow, and white!

This activity is great for younger students who have just been introduced to current electricity and circuits. Students decide what loops to complete to activate the colours they want.

The list of materials and instructions can be found below. The online store and catalog number is included with some of the materials to aid you in locating them.

Materials

-          Breadboard (All Electronics, PB-840)
-          Switch Holder (Digikey, ED2679-ND)
-          Switch (Digikey, GH7168-ND)
-          360 Ω Resistor
-          Two 270 Ω Resistors
-          TriColour LED (SuperBrightLEDs.com, RL5-RGB-DCA)
-          Battery Clip (All Electronics, BST-3)
-          9V Battery (Educational Innovations, BAT-40P)
-          Electrical Tape
 
Instructions
 
1.      Before the activity, prepare these items:
a.       Cut the large breadboards into small pieces, about 5 holes across. This is to make the flashlight small and compact, as it does not require a large breadboard.
b.      Place the switch into the switch holder, matching the 6 pins with the 6 holes.
c.       Shorten the resistors with wire cutters so that they can lay flat against the breadboard.
2.      Place the switch at the bottom of the breadboard to bridge the gap between the holes.
3.      Place the 360 Ω resistor above the switch on the leftmost pin, bridging the middle gap on the breadboard.
4.      Place the two 270 Ω resistors above the switch on the middle and rightmost pins, bridging the middle gap on the breadboard.
5.      Take the TriColour LED, and view it so that the pins' lengths from left to right are: short, long, medium, short. The short pin that is beside the long pin should be above and to the left of the 360 Ω resistor. The longest pin goes directly above the 360 Ω resistor. The medium and short pins that are beside each other go directly above the 270 Ω resistors.
6.      Place the red wire of the battery clip under the leftmost pin of the LED (the pin that is not matched with a resistor), and the black wire in the hole horizontal to the bottom pins of the switch.
7.      Attach the battery to the battery clip and ensure that the circuit is working properly.
8.      Wrap the flashlight in electrical tape to keep the components together.

 

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