Difference between revisions of "Traffic Light"

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(Electronics)
(Electronics)
 
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==Electronics==
 
==Electronics==
  
[[File:TrafficLightSchematic.png|thumb|900px|Schematic]]
+
[[File:TrafficLightSchematic.png|thumb|750px|Schematic]]
  
 
'''LED properties:'''
 
'''LED properties:'''
* Uledr = 2.0->2.5V
+
* Uled<sub>R</sub> = 2.0->2.5V
* Uledg = 3.2->3.6V
+
* Uled<sub>G</sub> = 3.2->3.6V
* Uledb = 3.2->3.8V
+
* Uled<sub>B</sub> = 3.2->3.8V
 
* I = 350mA
 
* I = 350mA
  
 
'''resistor calculation:'''
 
'''resistor calculation:'''
* UR = VCC - UT1 - UT4 - Uled
+
* UR = VCC - UT<sub>1,2,3</sub> - UT<sub>4</sub> - Uled
* URr = 5V - 0.3V - 0.3V - 2.0->2.5V = 2.4->1.9V
+
* UR<sub>R</sub> = 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
+
* UR<sub>G</sub>  = 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
+
* UR<sub>B</sub>  = 5V - 0.3V - 0.3V - 3.2->3.8V = 1.2->0.6V
  
  
 
* R = UR / I
 
* R = UR / I
* Rr = 2.4V / 0.3A = 8R
+
* R<sub>R</sub> = 2.4V / 0.35A = 6.857R
* Rg = 1.2V / 0.3A = 4R
+
* R<sub>G</sub> = 1.2V / 0.35A = 3.429R
* Rb = 1.2V / 0.3A = 4R
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* R<sub>B</sub> = 1.2V / 0.35A = 3.429R
 
note: we use the highest voltage and a slightly lower current as safety.
 
note: we use the highest voltage and a slightly lower current as safety.
  
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The power consumption of the resistors need to be calculated  
 
The power consumption of the resistors need to be calculated  
 
* PR = UR * I
 
* PR = UR * I
* PRr = 2.4V * 0.35A = 0.84W
+
* PR<sub>R</sub> = 2.4V * 0.35A = 0.84W
* PRg&b = 1.2V * 0.35A = 0.42W
+
* PR<sub>G,B</sub> = 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)
+
Conclusion: We will need resistors which be able to consume 1W for red and 0.5W for green and blue, or 2W and 1W if you use the safety standard of 25% spare
  
 
Because we use multiplexing...
 
Because we use multiplexing...
  
* Rr = 8R / 3 = 2R666 (We used 2R5 implemented as 2 resistors of 5R 1W in parallel)
+
* R<sub>R</sub> = 6.857R / 9 = 0R762 (We used 0R8 implemented as 2 resistors of 1R6 1W in parallel)
* Rg = 4R / 3 = 1R333 (We used 1R5 implemented as 2 resistors of 3R 1W in parallel)
+
* R<sub>G</sub> = 3.429R / 9 = 0R381 (We used 0R4 implemented as 2 resistors of 0R8 1W in parallel)
* Rb = 4R / 3 = 1R333 (We used 1R5 implemented as 2 resistors of 3R 1W in parallel)
+
* R<sub>B</sub> = 3.429R / 9 = 0R381 (We used 0R4 implemented as 2 resistors of 0R8 1W in parallel)
  
  
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P = U * I = 5V * 3.15A = 15.75W (a 25W supply should be enough)
 
P = U * I = 5V * 3.15A = 15.75W (a 25W supply should be enough)
  
an other less accurate way: we use 3W LEDs so if we have 9 times 3W it should be 27W without other parts of the circuit. This isn't correct because the leds don't consume 3W but if we calculate the power we give the leds it wil be maximum about 3.3V(average max LED forward voltage) * 350mA = 1.155W => 9 times = 10.395W without other parts of the circuit.
+
if we calculate the power we give the leds it wil be maximum about 3.3V(average max LED forward voltage) * 350mA = 1.155W => 9 times = 10.395W without other parts of the circuit.
  
 
==Lenses and Images==
 
==Lenses and Images==
  
 
I was thinking of making a mold out of wood using the CNC and use resin & hardener to make the lenses
 
I was thinking of making a mold out of wood using the CNC and use resin & hardener to make the lenses

Latest revision as of 00:49, 25 April 2014

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 DC 5V 50W
  • Transistors
  • Resistors
    • 12 * 10K
    • 6 * 5R
    • 12 * 3R
  • 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.

Electronics

Schematic

LED properties:

  • UledR = 2.0->2.5V
  • UledG = 3.2->3.6V
  • UledB = 3.2->3.8V
  • I = 350mA

resistor calculation:

  • UR = VCC - UT1,2,3 - 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 / 0.35A = 6.857R
  • RG = 1.2V / 0.35A = 3.429R
  • RB = 1.2V / 0.35A = 3.429R

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 1W for red and 0.5W for green and blue, or 2W and 1W if you use the safety standard of 25% spare

Because we use multiplexing...

  • RR = 6.857R / 9 = 0R762 (We used 0R8 implemented as 2 resistors of 1R6 1W in parallel)
  • RG = 3.429R / 9 = 0R381 (We used 0R4 implemented as 2 resistors of 0R8 1W in parallel)
  • RB = 3.429R / 9 = 0R381 (We used 0R4 implemented as 2 resistors of 0R8 1W in parallel)


The base resistors of the transistors we took some basic 10K resistors.


The power of the power supply

LED max current 350mA => 9 LEDs is 3.15A.

P = U * I = 5V * 3.15A = 15.75W (a 25W supply should be enough)

if we calculate the power we give the leds it wil be maximum about 3.3V(average max LED forward voltage) * 350mA = 1.155W => 9 times = 10.395W without other parts of the circuit.

Lenses and Images

I was thinking of making a mold out of wood using the CNC and use resin & hardener to make the lenses