## Wednesday, July 14, 2010

### Menghitung Resistor LED Putih (Super Bright White LED)

LED (light emitting diode) is currently being widely used, among other things, traffic signal lights and indicator lights of the vehicle. Efisasi value (lumens per watt) LED increasingly make this light source is used widely in the field of lighting.

Super bright white LED pic

LED is highly efficient light sources. Average white LED lamps that are marketed produce light efisasi of 32 lumens per watt (lm / W), and the results of the latest technological development is expected to produce 80 lm / W. LED operating life which has made a long-white LED light is very attractive.

Menghitung Resistor LED Super Bright Nyala Putih

The following formula to calculate the required resistance is as follows:

R = (Vs-Vd)/Id

With:
• R = resistance is needed (Ohm)
• Vs = voltage source / power supply (Volt)
• Vd = LED forward voltage (Volt)
• Id = LED forward current (Ampere)
Example:
Lights will be used 3 pieces LED, when the voltage source using a 12 VDC car batteries. The question now, what is the ideal resistor values to inhibit voltage 12VDC, so that the LED does not die quickly?

So, (-12V (3.6 V * 3)) / .03 A = 40Ω

Thus, the resistor value for 3 pieces LED lights that are installed in series 20Ω

how to install it as below

Notes:
• The voltage (Vd) and current (Id) white LED can be seen in the datasheet below
Datasheet 500TSW4DF Super Bright White 5mm LED
• DC Forward Current 30 mA
• Reverse Voltage (IR = 100mA) 5 V
• Forward Voltage 3.6 - 3.8 V
• Peak Pulse Forward Current (1) 100 mA
• Avg. Forward Current (Pulse Operation) 30 mA
• Operating Temperature -30 to +85 0C
• Storage Temperature -40 to +100 0C

Skema Rangkaian Elektronika