Changes
/* Calculation */
=== Calculation ===
==== Resistor in end line for vertical sgement ====
if the segment is alone, the end line resistor is of (example each element of the X letter) :
<math>
R_{1Seg} = \frac{Vcc - U_{seg}}{I_{LED}} = \frac{12V - 10V}{20mA}
Power dissipated by the resistor Rseg:
<math>
P_{R_{1Seg}} = R_{1Seg} \cdot I_{Led}^2 = 100 \cdot (20mA)^2
= '''40 mW'''
if the segments are linked by two, the end line resistor is of (example for the F, I, M, E letters) :
<math>
R_{1Seg} = \frac{Vcc - U_{seg}}{I_{LED_{Seg1}} + I_{LED_{Seg2}}} = \frac{12V - 10V}{20mA + 20mA}
= '''50 Ω'''
Power dissipated by the resistor Rseg:
<math>
P_{R_{1Seg}} = R_{1Seg} \cdot (2*I_{Led})^2 = 100 \cdot (40mA)^2
</math>
= '''80 mW'''
The choice for the resistor(s) value is : '''51 Ω 1/4W'''
==== Resistor in end line for horizontal sgement ====
if the segment is alone, the end line resistor is of (example each element of the M letter) :
<math>
R_{1LED} = \frac{Vcc - U_{seg_{LED}}}{I_{LED}} = \frac{12V - 2V}{20mA}
= '''500 Ω'''
Power dissipated by the resistor RsegR_LED:
<math>
P_{R_{1LED}} = R_{1LED} \cdot I_{Led}^2 = 500 \cdot (20mA)^2
</math>
= '''200 mW'''
The choice for the resistor(s) value is : '''510 Ω 1/4W'''
if the segments are linked by two, the end line resistor is of (example for the F letter) :
<math>
R_{LEDs} = \frac{Vcc - U_{LED}}{I_{LED1} + I_{LED2}} = \frac{12V - 2V}{20mA + 20mA}
= '''250 Ω'''
Power dissipated by the resistor RLED_2:
<math>
P_{R_{LEDs}} = R_{LEDs} \cdot (2*I_{Led})^2 = 250 \cdot (40mA)^2
= '''400 mW'''
if the segments are linked by three, the end line resistor is of (example for the E letter) :
<math>
R_{LEDs} = \frac{Vcc - U_{LED}}{I_{LED1} + I_{LED2} + I_{LED3}} = \frac{12V - 2V}{20mA + 20mA +20mA}
= '''167 Ω'''
Power dissipated by the resistor RLED_3:
<math>
P_{R_{LEDs}} = R_{LEDs} \cdot (3*I_{Led})^2 = 250 \cdot (60mA)^2
</math>
= '''601,2 mW'''
The choice for the resistor(s) value is : '''180 Ω 1W'''
= Layout =
