Monday, July 25, 2011

Infrared Technology


I finally decided I would get my hands on some IR technology and make something with it. Today I will be explaining how infrared light technology works. Look around you and you can see hundreds or even thousands of different colors. The colors we see are a type of light that are within the visible spectrum. What a lot of people don't realize is that there is light all around us that is not visible to the human eye. Radiation is a form of light we can't see and one type of radiation we get is the sun's rays that can cause skin cancer. Those sun rays that are harmful are called ultra-violet rays and you have probably heard about them. So at this point hopefully you understand that there is visible light (very small spectrum) and invisible light (very large spectrum). Most of the light in the universe can not be seen by the human eye so we are left with only a small "bandwidth" of light but it is quite beautiful as we all know. Infrared light is a type of light we can't see and we will be using it in an experiment.

The experiment I will talk about has to do with receiving frequencies of light. I will have an emitter that emits light at a certain frequency so we can pretend our emitter is a sun that emits only one frequency. Our detector will act as an eye ball that can only one color. Another words the detector can only see one color so the detector only gets alerted when our emitter shoots a beam of light at it. The eyeball filters out every single frequency of light except our one color coming from the emitter.

This type of emitter/detector setup is used in a lot of sensor applications. If you have a garage that stops moving when you are in the way of it then there is a sensor involved in that garage opener. In this case an emitter is planted on the ground to the left of the garage and the detector is planted on the ground to the right of the garage. When there is no interference/blockage of the light to the detector the garage opener will operate as normal. So when a person comes up to it, the person blocks the light and the detector realizes that and stops the garage door from moving. Another cool project would be to make a door sensor that rang an alarm whenever the door blocked the path of the light.

No comments:

Post a Comment