Build a Flashlight

00. Preparation

Materials and tools

Materials and tools

Sketch

Sketch

Circuit

Circuit

 

01. Circuit test

IMG_1539.JPG

The First try didn't work. Then I used Arduino to find out the problems.

The problems are:

1) I used the wrong feet of the pushbutton.

2) I confused the “+” and "-" of the LED, and also used only one 1.5V AA battery to power the 3V LED.

Then I made the right circuit below.

 

02. Make a container

The original design was based on the metal plate and semi-transparent plastic. But I can't use SHOP to cut the metal now. So I tried to build it with the plastic and black tape. 

However, the plastic is too crisp to crack, and I measured the whole size a little smaller than it should be. When I putted the batteries in it, the case couldn't fold very well and parts of the plastic broke off.

Bottom inside, battery's "+" side.

Bottom inside, battery's "+" side.

Parallel connected LED, battery's "-" side

Parallel connected LED, battery's "-" side

The bott0m and the top

As a result, although the flashlight works good, the appearance is a disaster. 

 

Summary

1) Making a neat appearance is way more difficult than making things work. 

2) There are lots of accidents about materials. Try it first before you choose it, and keep yourself a bunch of backup plans.

3) When I tested the circuit, sometimes the wire went very hot, sometimes the LED flashed then dead. So check the elements' parameters first to prevent danger.