If LEDs are used in any design for indication, backlighting or lighting, they must be correctly selected. These instruments have a variety of options and are available in various combinations.
Instructions
Step 1
Choose what wavelength the LED should have. Red color corresponds to a wavelength of about 635 nanometers, yellow - 570, light green - 550, emerald - 520, blue - 500, violet - 430. White LED has a wide spectrum and includes radiation with different wavelengths. Choose the color in accordance with with your preferences or the preferences of the customer. Remember that only red can be used to signal a danger, and blue and violet are not suitable for illuminating scales and indicators, when reading them, you need to strain your eyes. The colors of the vehicle lighting devices must correspond to those specified in the regulatory documents.
Step 2
Having decided on the wavelength, proceed to the choice of the geometric and optical parameters of the diode. Use round for lighting and indication. For the second purpose, you can also use rectangular LEDs, but it is difficult to make holes in the cases for them - you will not be able to drill them. Therefore, such diodes in scales are more appropriate. For directional illumination, use devices with lenses, for diffuse illumination - in matte housings. For strings where it is important that the diode is visible from any angle, use a tapered notch. If the installation of a low-power LED is supposed to be carried out on a board using automated equipment, it is better to use an SMD diode.
Step 3
Then determine the operating current of the diode. Remember that the power consumption is equal to the product of current and voltage. The voltage drop across the red white diode is from 3 to 4 V. The light power is equal to the product of the consumed and the efficiency. For indicator LEDs it is about 20 percent, for lighting LEDs it can reach 50. Please note that in some cases the use of several low-power LEDs is more economical than using a single one comparable in brightness.
Step 4
In some cases, the use of special types of LEDs is justified. So, two- and three-crystal diodes are capable of promptly changing color based on a signal from the control circuit. LEDs with built-in control circuit start blinking or change color (smoothly or abruptly, depending on the type) when power is applied. This allows various dynamic effects to be obtained without complicating the structure in which the diodes are installed.
Step 5
Having selected all the parameters, select the LED according to the reference book or catalog, or in consultation with the seller. If the website of the trade establishment is equipped with the corresponding function, enter the desired parameters of the diode in the form on it, after which only those names that suit you will be automatically filtered.
Step 6
When purchasing diodes, turn them on with the correct polarity. Operate them only at a current not exceeding the rated current.
