LED 3mm (Yellow)

Description

The 3mm Yellow LED is a small and efficient Light Emitting Diode (LED) that emits yellow light when current flows through it. It is commonly used in various applications such as indicators, displays, and lighting due to its small size, low power consumption, and bright illumination.

Overview of 3mm Yellow LED:

• Package Size: 3mm (a standard small LED size)
• Color: Yellow (emits yellow light, typically around 585–595 nm in wavelength)
• Transparency: Transparent lens (typically made of clear plastic), allowing the light to be emitted without much color filtering or diffusion.
• Typical Forward Voltage: 2.0V to 2.5V (typically around 2.1V for yellow LEDs)
• Typical Forward Current: 20mA (standard operating current)
• Luminous Intensity: Typically 150-250mcd (millicandela), depending on the specific model.
• Power Dissipation: Low power consumption, typically around 0.06W.

Pin Configuration:

An LED typically has two pins:

• Anode (+): The longer leg (positive terminal).
• Cathode (-): The shorter leg (negative terminal).

For a 3mm Yellow LED, the pinout is:

• Anode (+): Connect to the positive side of the power supply or circuit.
• Cathode (-): Connect to the negative side of the circuit (ground).

Electrical Characteristics of a 3mm Yellow LED:

• Forward Voltage (Vf): The voltage drop across the LED when it is forward-biased (i.e., when current is flowing through it). For a yellow LED, this voltage is typically between 2.0V and 2.5V.
• Forward Current: 20mA is the typical current value used to drive the LED for optimal brightness. Going beyond the rated current can overheat and damage the LED.

Applications of 3mm Yellow LED:

1. Indicator Lights:
   • 3mm yellow LEDs are often used in electronics as status indicators, such as power indicators, switches, or circuit boards. Yellow LEDs are commonly used to indicate a “warning” or “alert” status.
2. Displays:
   • Used in seven-segment displays, digital clocks, or alphanumeric displays, where the yellow LED provides a vibrant and eye-catching visual.
3. Lighting:
   • Decorative lighting in electronics, signs, or small lamps. Yellow LEDs are often used in LED strips or accent lighting for creating a warm, vibrant glow.
4. Automotive Lighting:
   • Many automotive applications use yellow LEDs for dashboard lights, indicator lights, or decorative lighting.
5. Toys and Gadgets:
   • Commonly found in toys, gadgets, and other consumer electronics where small, bright lights are needed.
6. Signals and Alarms:
   • Yellow LEDs can be used for signal lights or as part of alarm systems for visual signaling, especially in warning or cautionary scenarios.
7. Status Indicators:
   • Yellow LEDs are used in electronic devices to show that the system is in a specific state, such as standby, warning, or processing.

Current Limiting Resistor:

When using a 3mm Yellow LED, it’s important to use a current-limiting resistor to prevent excessive current, which could damage the LED. The resistor limits the current flowing through the LED.

How to Calculate the Resistor Value:

The general formula for calculating the current-limiting resistor for an LED is:

R=Vsupply−VfIfR = \frac{V_{supply} – V_f}{I_f}

Where:

• V_supply is the voltage supplied to the circuit.
• V_f is the forward voltage of the LED (typically 2.1V for a yellow LED).
• I_f is the desired forward current (typically 20mA = 0.02A).

Example:

If you are using a 5V power supply:

• V_supply = 5V
• V_f = 2.1V (yellow LED forward voltage)
• I_f = 20mA (typical forward current)

Substituting the values into the formula:

R=5V−2.1V0.02A=2.9V0.02A=145ΩR = \frac{5V – 2.1V}{0.02A} = \frac{2.9V}{0.02A} = 145\Omega

So, you would need a 145Ω resistor in series with the LED. A 150Ω resistor is a common standard value and would work well.

Brightness and Efficiency:

• Luminous Intensity: The brightness of a yellow LED is typically measured in millicandela (mcd). A typical 3mm yellow LED has a luminous intensity of around 150 to 250mcd, depending on the specific model and manufacturer. This is quite bright for such a small package.
• Power Consumption: The power consumed by the yellow LED is relatively low (in the range of 0.06W for typical current values), making it ideal for low-power applications.