Introduction: Simple LED Torch
This makes a great project for kids and adults from 8+, although there are scissors involved, and a couple of fiddly bits, so if you're a smaller kind of person, make sure you have a grown up handy, just in case....
- An LED
- 2 1.5v button cell batteris
- 2 pieces of 1mm thick hard plastic (i.e. styrene, HIPs, or slightly thicker polypropylene), both measuring around 50mm x 50mm
- 1 piece of 5/6mm thick foam (i.e. plastazote, or recycled mouse mat)
And some tools:
- A pair of sharp scissors
- Pencil and a felt tip
- Double sided tape
- A single hole punch
- Card, for templates
Step 1: Cutting
Make a template out of the piece of card - simple shapes (stars, flowers, hearts, circles for smiley faces...) work best, as the plastic has a nasty habit of cracking if you get too complicated.
Draw around your newly made template on both pieces of plastic and the foam, and cut all 3 out.
Step 2: Preparing the Foam
Before you can start putting the light up bits in, you need to make somewhere to house the components.
Use the single hole punch to make a hole in the centre of the foam layer. If you don't have a single hole punch available, you can use scissors to make the hole - if you're a smaller person, now is a good time to get that handy grown up to help out.
When you've done that, make a V shaped cut on the side of the foam, where you would like the LED to sit.
Step 3: Power! Light!
Right, lets add some batteries.
You need to make sure that both batteries go into the hole in the piece of foam, and, for the less technical amongst us, you need to make sure that they are facing the same way - you can't put them negative:negative or positive:positive, it won't work. There's some pictures below to help out if you're confused.
When the batteries are securely in their gap, slip the LED onto the piece of foam, so that the longer leg is against the positive, and the shorter is on the back, at the negative. The foam should be between the legs of the LED. Again, there's pictures to help.
Test that your LED works by pressing everything together over the battery - if it doesn't, check that the batteries are the right way round and that the LED is the right way round too.
Step 4: Assembly
All there is to do now, is to stick everything together!
Use the double sided sticky tape to attach the two white plastic parts to the foam. make sure you stick over the battery/LED to stop anything escaping.
Once it's all stuck, test again, and then, if you want, you can decorate it with coloured sharpies or similar.
Step 5: The Teachery Stuff....
- Introducing basic product design
- Filling up short terms/breaks between long projects
- As a taster, for younger students coming up to secondary school
- As a simple electronics project for primary age kids, or lower level groups in the younger years at secondary school.
I've also done it in conjunction with branding projects in graphics, and used it as a "product" that can be cut to shape and logo'd, either by hand, or using CAD/CAM equipment.
Objectives can be anything - "understanding that components have polarity", "understanding how to design for a specific client", "an awareness of different types of switches" (pressure switch) etc......