Consumption of circuit elements 1. basic led circuit
2020-04-19 - Kiss J Gabor
The basic led circuit
The basic datas of cirquit
White led 5 mm.
| attribute | value | unit |
|---|---|---|
| Vsource | 9,0 | V |
| VLED | 3,6 | V |
| ILED | 30,0 | mA |
| PLED (P=V×I) | 0,108 | W |
Calculating resistor power with R470
The voltage drop across the resistor: 9,0 V - 3,6 V = 5,4 V.
The power dissipated by the resistor (P2 = V2 / R): 5,4<sup>2</sup> / 470 = 0,061 W.
Calculating resistor power with R220
The voltage drop across the resistor: 9,0 V - 3,6 V = 5,4 V.
The power dissipated by the resistor (P2 = V2 / R): 5,4<sup>2</sup> / 220 = 0,133 W.
Calculating efficiency (η) with R470
The efficiency according to the layout (η = PLED/Psum): 0,108 / (0,108 + 0,061) = 0,639 = 63,9 %.
Calculating efficiency (η) with R220
The efficiency according to the layout (η = PLED/Psum): 0,108 / (0,108 + 0,133) = 0,450 = 45,0 %.
LED effeciency in the timeline
| time period | -1990 | 1990-2000 | 2000-2010 | 2010-2020 |
|---|---|---|---|---|
| effeciency ηLED | 0,03% | 0,5-2% | 2-15% | 5-20%(?) |
Links:
Simple LED Circuits
LED lighting from 230V mains
electronicsDisplay η :
html:η= η,Η= Η
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linux keyboard:left-ctrl+shift+uand “03B7”.