Electrical Schematics Pictures

Menentukan Nilai Resistor Pada LED │ Determining the Value Resistors On LED

How to choose a resistor to turn on the LED? Why LEDs need resistors? That's because the LED does not have a current regulator, the LED will burn out if no resistor.

The amount of flow determines how bright an LED. Greater flow of the lighter flame of an LED. Current in the LED should be approximately 10-20 mA. When a current passes through a LED, the LED voltage drop of about 1.85 V or depending on the type of LED that is in use

To determine the resistor on the led first consider the graph above (right graph ). Choose the desired LED light and use this chart to determine the required flow. For example, if the desired luminous intensity (high / dark light an LED) for 1, can be seen that the currents are in need of 20 mA.

This shall mean the current 20 mA to pass through the LED, to get the brightness of LED = 1. Now, we can calculate the voltage drop across the LED based on a known flow. Look at the graph on the left at 20 mA. Now you know that the fall in voltage of 1.85 V. Know that the voltage drop across the LED is not only a function of current, but also the color of the LED and the temperature (because of chemical differences in the LED).

Color Potential Difference (LED voltage)

    * Infrared : 1.6 V
    * Red : 1.8 V - 2.1 V
    * Orange : 2.2 V
    * Yellow : 2.4 V
    * Green : 2.6 V
    * Blue : 3.0 V - 3.5 V
    * White : 3.0 V - 3.5 V
    * Ultraviolet : 3.5 V

The following example circuit LED (Menentukan Nilai Resistor Pada LED) series / parallel based on Ohm's law, V = IR to refer to the list above the LED voltage

Resistor values = (voltage source - LED voltage) / LED current

* Red LED resistor values (12 V- 1.8V) /0.02 A = 510 ohms
* Blue LED resistor values (12V - 3V) / 0.02 A = 450 ohms

Resistor values = (voltage source - the total LED voltage) / LED current

* Resistor values = (12V - 9.6 V) / 0.02 A = 120 ohms

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. Electrical Schematics to Calculating Resistor LED:

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