Adafruit 1621 White LED Backlight Module User Manual

1. Introduction

The Adafruit 1621 White LED Backlight Module is a plastic-diffused backlight designed for various lighting applications, commonly found in LCD displays. This module features a single white LED encased within a 3.5mm thick acrylic strip, providing uniform light diffusion. A reflector on one side ensures light is directed efficiently from the top surface. These modules are suitable for custom lighting projects, wearable electronics, and display enhancements.

Figure 1: Adafruit 1621 White LED Backlight Module. This image shows the rectangular white LED backlight module, highlighting its compact design and diffused light surface.

2. Safety Information

Please read and understand the following safety precautions before using the Adafruit 1621 LED Backlight Module:

• Power Supply: Ensure the power supply voltage does not exceed 3V and the current does not exceed 20mA. Over-voltage or over-current can damage the LED.
• Resistor Use: Always use an appropriate current-limiting resistor when connecting the LED module to a power source to prevent damage.
• Polarity: Observe correct polarity when connecting the module. Incorrect polarity will prevent the LED from lighting and may cause damage.
• Handling: Handle the module with care to avoid physical damage to the acrylic strip or internal components.
• Heat: While LEDs are efficient, prolonged operation at maximum current may generate some heat. Ensure adequate ventilation if embedding in an enclosed space.

3. Package Contents

Each package typically contains:

• 2 x Adafruit 1621 White LED Backlight Modules (45mm L x 86mm W)

Note: Additional components such as resistors, wires, or power supplies are sold separately and are required for operation.

4. Setup

To set up your Adafruit 1621 LED Backlight Module, follow these steps:

1. Identify Connections: The module has two leads for power connection. Typically, the longer lead is positive (+) and the shorter lead is negative (-). Consult the product datasheet or Adafruit's official documentation for precise pin identification if unsure.
2. Select Power Source: A 3V DC power source is recommended. This can be a battery (e.g., a coin cell battery) or a regulated power supply.
3. Calculate Resistor Value: To limit the current to 20mA (0.02A) at 3V, a current-limiting resistor is necessary. Using Ohm's Law (R = V/I), for a 3V source and 20mA current, the resistor value would be R = 3V / 0.02A = 150 Ohms. A common practice is to use a slightly higher resistance (e.g., 180-220 Ohms) to ensure longevity, especially if the exact forward voltage of the LED is unknown or varies. For a 5V USB power source, a 100 Ohm resistor is often used to achieve a similar current.
4. Connect Resistor: Solder or connect the calculated current-limiting resistor in series with the positive (+) lead of the LED module.
5. Connect Power: Connect the positive (+) side of the resistor to the positive terminal of your 3V power source. Connect the negative (-) lead of the LED module directly to the negative terminal of your power source.
6. Test: Apply power to the circuit. The LED backlight should illuminate uniformly.

5. Operating Instructions

Once properly connected, the Adafruit 1621 LED Backlight Module operates by emitting a uniform white light. Its primary function is to provide backlighting for various projects.

• Light Diffusion: The acrylic strip effectively diffuses the light from the single LED, creating an even glow across its 45mm x 86mm lit area.
• Customization:
  • Masking: The module's shape can be customized by applying vinyl masks or drawing directly onto its surface with markers to create specific illuminated patterns or designs.
  • Color Gels: Color gels can be placed over the module to change the emitted light color, allowing for diverse aesthetic effects.
• Integration: These modules are suitable for integration into custom enclosures, display panels, or wearable electronic projects where a compact, diffused light source is required.

6. Maintenance

The Adafruit 1621 LED Backlight Module requires minimal maintenance to ensure optimal performance and longevity.

• Cleaning: If the acrylic surface becomes dusty or smudged, gently wipe it with a soft, lint-free cloth. For stubborn marks, a slightly damp cloth with water can be used, followed by immediate drying. Avoid abrasive cleaners or solvents.
• Storage: Store the modules in a dry, cool environment, away from direct sunlight and extreme temperatures.
• Physical Inspection: Periodically inspect the module for any signs of physical damage, such as cracks in the acrylic or damaged wiring connections.
• Power Management: Ensure the module is always operated within its specified voltage and current limits to prevent premature degradation of the LED.

7. Troubleshooting

If you encounter issues with your Adafruit 1621 LED Backlight Module, refer to the following troubleshooting guide:

8. Specifications

Key specifications for the Adafruit 1621 White LED Backlight Module:

• Model Number: 1621
• Dimensions (L x W x H): 86mm x 45mm x 3.5mm (3.39"L x 1.77"W x 0.14"H)
• Lit Area: 45mm x 86mm
• Color: White
• Light Source Type: LED
• Material: Plastic, Acrylic (shade)
• Operating Voltage: 3 Volts DC (typical)
• Operating Current: 20 Milliamps (typical)
• Brightness: 80 Millicandela
• Number of Light Sources: 1
• Features: Diffused light, reflector for top emission, customizable shape (with masking), color-changing (with gels).

9. Warranty and Support

Adafruit products are designed for hobbyists and professionals. For specific warranty information, please refer to the terms and conditions provided at the time of purchase or visit the official Adafruit website.

For technical support, product documentation, or community forums, please visit the Adafruit website:

www.adafruit.com