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2.1

Major VersionM

by Vishal Bhatt

Introduction

While conducting these experiments we will see, that coloured pigments and coloured light mix differently.

So one would use different colour pallets when dealing with pigments, painting, for example, versus when dealing with coloured light, in the case of lighting and screens in electronic devices.

Video Overview

    • Scissors have functional sharp edges which may result in injury. Always keep blades away from fingers and body and handle with care.

    • Terminals of electronic components might break, if twisted too much. Ensure good electrical contact while joining terminals together but take care not to twist too much.

  1. The DIY Battery Holder is designed to provide 3V using two AA cells and some foam piece, aluminium tape, connecting wire and a cardboard base. For more details on how to make it, go to DIY Battery Holder
    • The DIY Battery Holder is designed to provide 3V using two AA cells and some foam piece, aluminium tape, connecting wire and a cardboard base. For more details on how to make it, go to DIY Battery Holder

  2. In the circuit diagram, negatives of the red, green and blue LEDs are  connected at the point 'A'. Positive of the red  LED and negative of the diode are connected at point 'B'. Positives of the diode, green and blue LEDs are connected at point 'C'.
    • In the circuit diagram, negatives of the red, green and blue LEDs are connected at the point 'A'. Positive of the red LED and negative of the diode are connected at point 'B'. Positives of the diode, green and blue LEDs are connected at point 'C'.

  3. Draw an equilateral triangle of side 2.5  cm, at the centre of the card sheet. Mark three vertices of the triangle as 1, 2 and 3. These markings will be used as a reference for placing LEDs. Place  red, green and blue LEDs at 1, 2 and 3 respectively.
    • Draw an equilateral triangle of side 2.5 cm, at the centre of the card sheet.

    • Mark three vertices of the triangle as 1, 2 and 3. These markings will be used as a reference for placing LEDs. Place red, green and blue LEDs at 1, 2 and 3 respectively.

  4. Identify the colour of the LEDs, by connecting each one to the battery and testing them While connecting the red LED, make sure the diode is connected in series with the LED. Never connect the red LED directly to the 3V battery.battery (as it has a lower turn-on potential, compared to the blue and green LED and can get burnt). In the materials provided by ThinkTac, the red LED is packed separately with a diode.
    • Identify the colour of the LEDs, by connecting each one to the battery and testing them

    • While connecting the red LED, make sure the diode is connected in series with the LED. Never connect the red LED directly to the 3V battery.battery (as it has a lower turn-on potential, compared to the blue and green LED and can get burnt).

    • In the materials provided by ThinkTac, the red LED is packed separately with a diode.

  5. Insert the red LED by pushing it, into the cardboard at marking '1'. Now identify the positive pin/lead (longer) of the red LED behind the card sheet. Follow the same procedure as above for the green and blue LEDs  at  markings '2' and '3' respectively.
    • Insert the red LED by pushing it, into the cardboard at marking '1'.

    • Now identify the positive pin/lead (longer) of the red LED behind the card sheet.

    • Follow the same procedure as above for the green and blue LEDs at markings '2' and '3' respectively.

    • If the LED has two leads that are equal in length, then you can look at the metal plate inside the LED. The smaller plate indicates the positive (anode) lead; the larger plate indicates the negative (cathode) lead.

  6. Mark the LED points as 'R', 'G' and 'B', respectively, on the back of the cardboard, by referring to the corresponding LED in the front. Make sure that the green and blue LEDs are inserted such that the negative pins of both the LEDs are close to the red LED. Connect the negative pins of the green and blue LEDs by twisting them together.
    • Mark the LED points as 'R', 'G' and 'B', respectively, on the back of the cardboard, by referring to the corresponding LED in the front.

    • Make sure that the green and blue LEDs are inserted such that the negative pins of both the LEDs are close to the red LED.

    • Connect the negative pins of the green and blue LEDs by twisting them together.

    • Connect the negative pin of the red LED to the connected negative pins of the green and blue LEDs. Now you have a common negative terminal. In the circuit diagram, this is referred to as 'A'.

    • Now you are left with three positive pins, one from each LED.

  7. Take the diode; the negative pin of the diode can be identified by the white/silver strip on its body. The diode is used to prevent the red LED from burning out (as it has a lower turn-on potential, compared to the blue and green LED).
    • Take the diode; the negative pin of the diode can be identified by the white/silver strip on its body.

    • The diode is used to prevent the red LED from burning out (as it has a lower turn-on potential, compared to the blue and green LED).

    • Now connect this negative pin of the diode to the positive pin of the red LED by twisting them together.

  8. Connect the positive pins of both the green and blue LEDs together. Now you should have two positive pins, one from the combined green and blue LEDs and another one from the diode connected to the red LED. Tie these together by twisting them. This is the common positive point. In the circuit diagram, this is referred to as point 'C'.
    • Connect the positive pins of both the green and blue LEDs together.

    • Now you should have two positive pins, one from the combined green and blue LEDs and another one from the diode connected to the red LED. Tie these together by twisting them. This is the common positive point. In the circuit diagram, this is referred to as point 'C'.

    • Check and make sure whether the connections are as per the circuit diagram given in the first step.

  9. Remove the insulation from both the ends of the connecting wires, as shown in the picture. Connect one wire to the common positive terminal. Make a hole on the left side, next to the triangle with scissors and insert the positive wire through it, from back to front.
    • Remove the insulation from both the ends of the connecting wires, as shown in the picture.

    • Connect one wire to the common positive terminal.

    • Make a hole on the left side, next to the triangle with scissors and insert the positive wire through it, from back to front.

  10. Connect the other wire to the common negative terminal. Make a hole in the cardboard on the right side and insert the wire, as was done for the positive lead.
    • Connect the other wire to the common negative terminal.

    • Make a hole in the cardboard on the right side and insert the wire, as was done for the positive lead.

    • Make sure that the positive and negative connections don't touch each other.

  11. Now connect the positive and negative leads to the positive and negative terminals of the battery holder respectively. All three LEDs should immediately illuminate with about the same brightness. All three LEDs should immediately illuminate with about the same brightness.
    • Now connect the positive and negative leads to the positive and negative terminals of the battery holder respectively.

    • All three LEDs should immediately illuminate with about the same brightness.

  12. Cast the light of the LED on a wall in a dark room to observe the pattern made by the intersecting LED lights. You can also place an object between the LEDs and the wall to observe the effects of the shadows it casts. You can also place an object between the LEDs and the wall to observe the effects of the shadows it casts.
    • Cast the light of the LED on a wall in a dark room to observe the pattern made by the intersecting LED lights.

    • You can also place an object between the LEDs and the wall to observe the effects of the shadows it casts.

    • If one or more of the LEDs don't turn on, then check their polarities and make sure they match the battery's polarity.

    • If none of the LEDs turn on, then check all the connections and try flipping the polarity of the main lead wires.

  13. Make different shapes of holes in a piece of cardboard and place this between the LED set-up and a white wall. Play and observe. Make cardboard strips of around 2cm x 4cm. Poke two LEDs through each cardboard strip: red+blue, red+green and green+blue. Mix the secondary colours and observe what happens. Insert the LEDs on the cardboard in different orientations. Connect them as shown in the circuit of the above set-up and observe.
    • Make different shapes of holes in a piece of cardboard and place this between the LED set-up and a white wall. Play and observe.

    • Make cardboard strips of around 2cm x 4cm. Poke two LEDs through each cardboard strip: red+blue, red+green and green+blue. Mix the secondary colours and observe what happens.

    • Insert the LEDs on the cardboard in different orientations. Connect them as shown in the circuit of the above set-up and observe.

    • Shine the tri-LED set-up on different coloured sheets. This is another way of demonstrating colour addition.

    • To learn and make these variations, go to Colour - Addition (Variations)

  14. Take any 3 light-coloured sketch pens; we have used pink, yellow and blue. Take a filter paper. Draw a circle and fill it with any of the colours, pink in our case.
    • Take any 3 light-coloured sketch pens; we have used pink, yellow and blue.

    • Take a filter paper.

    • Draw a circle and fill it with any of the colours, pink in our case.

  15. Make another circle with a different  colour  (blue, in our case) overlapping the pink circle. Fill the circle with blue colour. Make a third circle with the third colour (yellow here) overlapping the previous coloured circles.
    • Make another circle with a different colour (blue, in our case) overlapping the pink circle.

    • Fill the circle with blue colour.

    • Make a third circle with the third colour (yellow here) overlapping the previous coloured circles.

  16. Fill the third circle with yellow colour. You should notice that the colours when drawn on top of each other, create a darker spot. After a few more layers of colour are added on, you'll get pretty close to black, as shown.
    • Fill the third circle with yellow colour.

    • You should notice that the colours when drawn on top of each other, create a darker spot. After a few more layers of colour are added on, you'll get pretty close to black, as shown.

    • Filter paper can tear easily, so do not colour it with too much pressure, especially at the intersection of colours.

    • Using darker hues/colours may create a black spot with just 2 colours, so use lighter colours for a better effect.

  17. Variation 1 :  Black ink chromatography. Variation 2 : Colour wheel. Variation 3 : RGB LEDs.
Finish Line

Madhushree HS

Member since: 05/02/2017

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