Service learning as a teaching method combines community service with academic instruction that focuses on critical, reflective thinking and civic responsibility. Service learning programs involve students in organized community service that addresses local and global needs, while developing their academic skills, sense of civic responsibility, and commitment to the community. Internships offer ways individuals can learn from valuable work experiences while also contributing to the host's mission.
Service learning using Appropedia helps to create an essential knowledge base for the world via learning experiences for individuals and classes.
LED traffic light FAQ. Here are a number of frequently asked questions concerning retrofitting street lights with LEDs. For full information see LED.
What does an LED traffic light look like? An LED traffic light looks very similar to a regular traffic light. It still gets the job done and is actually brighter. An LED is actually very small and therefore the traffic light is made up of a bunch of smaller lights, this is apparent when you look closely. The color of the light depends on the exact composition inside the bulb. Who Invented the LED? It all began when Oleg Vladimirovich created the first LED in 1927. There was no practical use for it until 1962 when it was discovered that the infrared LED could be changed into a visible red LED. How does an LED work? An LED is basically a tiny light bulb with a semiconductor diode in place of a filament. Inside the diode, there are positively and negatively charged areas. When a voltage is applied to the diode with the positive end hooked up to the negative area and the negative end hooked up to the positive area the electrons inside become excited and jump from the positively charged to negatively charged areas. This interaction produces light. What is a diode? A diode is a component that restricts the directional flow of charge carriers. In other words, a diode allows an electric current to flow in one direction, but blocks it in the opposite direction.
Sign up for an Appropedia internship! We have 2012 opportunities for students of Engineering, Permaculture, International Development Studies, Architecture, Urban Planning, Communications, Computer Science, Web Design and related disciplines.