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Unformatted text preview: www.enginuity.org.uk student sheet traffic lights (1 of 2) David Mellor is an award-winning cutlery designer. He also designs traffic lights. His designs have been used in the UK for more than 40 years. However, he doesn’t design the electronic control systems that make traffic lights work. That’s down to engineers. T ra ffi c lights Cutlery cabinets and traffic lights in the Design Museum Investigate how you can use electronics to: turn lights on and off automatically in the correct sequence (the right order) •¡ adjust the timing of the sequence •¡ build a circuit that operates a set of model traffic lights correctly. •¡ your task Which component(s) can you use, instead of mechanical switches, to turn lights on and off? What sequence of red, green and amber lights do you need? How can you turn the lights on and off at the right times to get this sequence? Can you adjust the length of time the lights stay on? Must all three stay on for equal lengths of time? Or can you make the green light stay on longer than the amber, and the red stay on longer still? To control traffic, several sets of lights have to work together. When you can control one set, you could try something more complicated, such as: pedestrian crossing, with lights for people as well as traffic •¡ road works, allowing traffic in one direction at a time •¡ T-junction •¡ crossroads •¡ T-junction or cross roads with left filter. •¡ some things to think about photo by kind permission of Phil Sayer and David Mellor Design Company www.enginuity.org.uk student sheet traffic lights (2 of 2) Make sure you are familiar with the electronics kit. Find out: 1. ~ what electronic components you’ve got ~ what each component does ~ how to connect components together to build a circuit. In particular, you need to know how to use a timer and decade counter to turn LEDs on and off in sequence. You will be given a timer-counter circuit. Add the necessary components so that the circuit lights up 2....
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This note was uploaded on 04/09/2009 for the course FEM SKP2204 taught by Professor Drlee during the Spring '09 term at Punjab Engineering College.
- Spring '09