Difference between revisions of "Traffic Light"

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* Controller => [http://arduino.cc/de/Main/ArduinoBoardProMini Arduino pro mini]
 
* Controller => [http://arduino.cc/de/Main/ArduinoBoardProMini Arduino pro mini]
 
* Power Supply 230Vac to 5Vdc
 
* Power Supply 230Vac to 5Vdc
* Transistors =>
+
* Transistors
 
** 9 * [http://www.fairchildsemi.com/ds/BC/BC337.pdf BC337]
 
** 9 * [http://www.fairchildsemi.com/ds/BC/BC337.pdf BC337]
 
** 3 * [http://www.fairchildsemi.com/ds/TI/TIP42.pdf TIP42]
 
** 3 * [http://www.fairchildsemi.com/ds/TI/TIP42.pdf TIP42]
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==How it works==
 
==How it works==
 +
 +
[[File:TrafficLightSchematic.png|thumb|800px|Schematic]]
  
 
'''LED properties:'''
 
'''LED properties:'''
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'''resistor calculation:'''
 
'''resistor calculation:'''
* UR = VCC - UT1 - UT2 - Uled
+
* UR = VCC - UT1 - UT4 - Uled
 
* URr = 5V - 0.3V - 0.3V - 2.0->2.5V = 2.4->1.9V
 
* URr = 5V - 0.3V - 0.3V - 2.0->2.5V = 2.4->1.9V
 
* URg = 5V - 0.3V - 0.3V - 3.2->3.6V = 1.2->0.8V
 
* URg = 5V - 0.3V - 0.3V - 3.2->3.6V = 1.2->0.8V
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* Rg = 4R / 3 = 1R333
 
* Rg = 4R / 3 = 1R333
 
* Rb = 4R / 3 = 1R333
 
* Rb = 4R / 3 = 1R333
 
[[File:TrafficLightSchematic.png|frame|Schematic]]
 

Revision as of 21:20, 3 December 2013

We are converting a regular traffic light to a Peace-Love-Linux traffic light.

PEACE - LOVE - LINUX

Materials

  • 3 * 3W RGB LEDs.
  • Controller => Arduino pro mini
  • Power Supply 230Vac to 5Vdc
  • Transistors
  • Resistors
  • How do we gonna make the images?

Maybe it would be a good thing to make a system to mount it, so it will no longer need to lay stand on the ground.

How it works

Schematic

LED properties:

  • Uledr = 2.0->2.5V
  • Uledg = 3.2->3.6V
  • Uledb = 3.2->3.8V
  • I = 350mA

resistor calculation:

  • UR = VCC - UT1 - UT4 - Uled
  • URr = 5V - 0.3V - 0.3V - 2.0->2.5V = 2.4->1.9V
  • URg = 5V - 0.3V - 0.3V - 3.2->3.6V = 1.2->0.8V
  • URb = 5V - 0.3V - 0.3V - 3.2->3.8V = 1.2->0.6V


  • R = UR / I
  • Rr = 2.4V / 0.3A = 8R
  • Rg = 1.2V / 0.3A = 4R
  • Rb = 1.2V / 0.3A = 4R

note: we use the highest voltage and a slightly lower current as safety.


The power consumption of the resistors need to be calculated

  • PR = UR * I
  • PRr = 2.4V * 0.35A = 0.84W
  • PRg&b = 1.2V * 0.35A = 0.42W

Conclusion: We will need resistors which be able to consume 2W for red and 1W for green and blue. (according to the safety standard of 25% spare)

Because we use multiplexing...

  • Rr = 8R / 3 = 2R666
  • Rg = 4R / 3 = 1R333
  • Rb = 4R / 3 = 1R333