In this circuit, a resistor is not needed to reduce the current flowing through the light‑emitting diodes. All of the positive leads of the l.e.d.s are connected to the positive side of the battery. All of the negative leads of the l.e.d.s are connected to the negative side of the battery. This is an example of a circuit where the components are connected “in parallel”.

The three l.e.d.s flash independently at slightly different rates to produce a sparkling display. Unfortunately, it is not possible to alter the rate at which the l.e.d.s flash.

This project requires two AA batteries (not supplied in this kit). In a test of this circuit, a set of Duracell Plus Power batteries was still producing a good output of light after 400 hours of continuous use.

To construct this project you will need to use the following tools (not supplied):

  • small, low power soldering iron, e.g. 15 watt, 18 watt or 25 watt
  • small pliers for bending component leads and link wire
  • small wire cutters for cutting component leads and link wire.


Assembly Instructions for Project 8: Sparkling L.E.D. Triangle
Please refer to the wiring diagram and read through these instructions very carefully before starting assembly.

close up of track

surface showing

soldered joints

close-up of top surface

showing wire link

and two l.e.d.s

2.      Choose one of the l.e.d.s. and identify its positive and negative leads. A light-emitting diode will not work if it is connected the wrong way around and so correct identification of the leads is important! Push the negative lead, without bending it, through hole I7 and, using pliers, bend the positive lead so that it fits through A7. Spread the ends of the leads slightly apart and carefully solder. Avoid solder splashing across the copper tracks where you have soldered the l.e.d. Trim excess wire from the wire link and from the leads of the l.e.d. using wire cutters.

3.      Choose a second l.e.d. Push the negative lead, without bending it, through C12 and bend the positive lead so that it fits through A12. Spread the ends of the leads slightly apart and carefully solder. Trim the excess wire from the leads of this l.e.d. The pictures below show this stage of construction:

example of a

link wire "staple"


Colours

PROJECT 8:   SPARKLING L.E.D. TRIANGLE

Irby Electronics

Irby Electronics

1.      Cut a piece of link wire and, using pliers, bend it to form a shape like a staple, as shown below. Push this staple through the top surface into holes C2 and I2 and bend the ends of the wire link slightly apart. Solder the wire link to the track surface. This wire link will connect all of the negative leads of the l.e.d.s together.

Think  SAFETY.   Act  SAFELY.

You're important . . . so also read through the safety guidance sheet provided with the kit.

Skill level:      * *            INTERMEDIATE
Project constructed on track board.
Soldering essential
.

This circuit contains three light-emitting diodes arranged in the shape of a triangle. The circuit diagram is shown below.

4.      Push the negative lead of the third l.e.d., without bending it, through I17 and bend the positive lead so that it fits through A17 and. Spread the ends of the leads slightly apart, solder and trim the excess wire from the leads. All of the positive leads of the l.e.d.s are now connected together.

5.      Push a terminal pin from the track surface through to the top surface in position A25 and solder on the track surface. The terminal pin is a tight fit and pliers are usually needed to squeeze it through the hole. Push another terminal pin through position
I25 and solder it. (Terminal pins have a habit of jumping off the table and are never found again – two spare terminal pins are provided in the kit.)

6.      Twist the red lead from the battery box around the terminal pin in position A25 and solder them together. Twist the black lead from the battery box around the terminal pin in position
I25 and solder them together.

7.      Assembly is now complete. Carefully compare your circuit with the wiring diagram and the pictures above. Correctly place two new AA batteries into the battery box and switch on.

Enjoy!


  • If your circuit doesn’t work and the batteries become hot then you have made a short‑circuit. This is a potential fire hazard! Switch off immediately, remove the batteries  and check your circuit to find the problem before continuing.
  • If the problem isn’t a short‑circuit, please recheck your soldering and your batteries.