Simple LED torch
This is a really simple little LED torch that uses a small 3D printed holder a Li 3V button battery (CR2032) and a high brightness LED. The battery fits into the circular hole so that the main body (the positive electrode) is downward and the smaller (negative electrode) face points upward. I have included a small hole in the base so that you can use a screwdriver to push the battery out if you want to remove it. At the side there are two small holes for the LED wires. The LED is simply pushed into these two holes so that the longer wire of the LED (the positive connection) goes under the battery, making connection with the positive of the battery. The negative connection of the LED goes across the front of the battery. A small piece of plastic tube (obtained from a stripped wire) is used to stop the wire shorting the battery. I bend the wire around to make a bit of a loop that is a mm or so above the battery connection. When you press the wire it will connect on to the negative of the battery completing the electrical circuit and the LED lights. Note the LED should really have a series current limiting resistor but the total internal resistance of the battery and LED is great enough so that the LED is not damaged.
THE CREATIVE SCIENCE CENTRE
Dr Jonathan Hare University of Sussex, Brighton.
home | diary | whats on | CSC summary | latest news