• Skip to main content
  • Skip to primary sidebar

Homemade Circuit Projects

Get free circuit help 24/7

New Projects | Privacy Policy | About us | Contact | Disclaimer | Copyright | Videos 

You are here: Home / Datasheets / How to Understand and Use white LEDs – Datasheet

How to Understand and Use white LEDs – Datasheet

Last Updated on January 1, 2020 by Swagatam 8 Comments

If you are wondering how to correctly use white LEDs in circuits so that they can be illuminated safely without damaging, then this post might help you to evaluate the same.

Introduction

White LEDs are the future lighting solutions for our cities and homes. They will be easily replacing the traditional CFL and other flurescent types of light producing devices. LEDs are extremely efficient when it comes to power consumption issues and are also highly durable and reliable with its specified features.

The invention of LED technology was a complete revelation, and it opened the doors to the researchers for exploring a whole new concept of lighting involving tiny devices which could produce immense illumination using very little electric power.

caution electricity can be dangerous

Today the concept may look old, yet still, LEDs especially white LED technology is improving at a very rapid pace. LED industry is surely growing and introducing advanced and more efficient versions of LEDs to us. Also these devices are getting very popular even with the common population and folks are seen using them and customizing them as per there own preferences.

Though white LEDs may look simple devices and illuminating them may not require more than a couple of pen light cells, white LEDs if not maintained or operated within a specific power range, might just fail in every respect.

Here we are going to discuss some of the basic tips regarding operating or illuminating these wonderful devices safely and optimally.

Before studying the above through a simple application circuit, it would be important to understand some of the following important specifications related to white LEDs.

Important Specifications associated with White LEDs

In general most of the white LED types are specified with a maximum forward voltage drop of not more than 3.5 volts AC/DC.

Forward voltage drop means the maximum safe operating voltage of a particular LED at which the LED illuminates with maximum intensity without the danger of getting damaged.

The minimum current required by most white LED types at the above voltage is 10 mA, 20 mA being the optimal range, however these devices are able to operate even with 40 mA of current, producing dazzling brightness, almost at eye blinding levels.

Normal 5mm and 3mm types of white LEDs have two lead terminals, assigned as the cathode and the anode, or in layman’s words, a positive and a negative.

The cathode or the negative lead is relatively smaller in length than the anode or the positive lead and this also makes the terminals easily distinguishable.

For operating the device, the longer lead is connected to the positive while the smaller lead is connected with the negative of the power supply.

If the connected power to the LED is within the specified 3.5 volt range, then a series resistor may not be required to be connected with the LED.

However, if the supply voltage is more than the above limit, inclusion of a resistor becomes imperative.

Failing to do so may the burn the LED and damage it instantly.

 

how to add resistor to a LED

The value of the of the resistor will depend on the magnitude of the applied voltage, and may be calculated using the following formula:

R = (Us – Fwd.)/I(current),

where R is the resistance value which needs to be calculated, Us is the supply voltage, Fwd is the forward voltage drop of the LED and I is the current magnitude which is required to be supplied to the LED.Suppose the supply voltage is 12, the forward voltage drop and the current as explained above are taken as 3.5 and 20 respectively, R may be calculated as:

R = (12 – 3.5)/0.02 = 425 Ohms.

In general the forward voltage drop of a particular LED becomes the important factor while issuing the operating input to the device, rest of the parameters ae not absolutely critical.

The forward voltage drop of an LED may be easily found out by connecting the particular device to a digital multimeter prods selected at the diode range.

The displayed figure directly provides the forward voltage range of the particular LED.

You'll also like:

  • 1.  Stereo FM Transmitter Circuit using IC BA1404
  • 2.  Triacs – Working and Application Circuits
  • 3.  How PNP Transistors Work
  • 4.  How to use Eagle CAD
  • 5.  High Stability of Crystals in Oscillator Circuits
  • 6.  Types of Inductors Explored

About Swagatam

I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials.
If you have any circuit related query, you may interact through comments, I'll be most happy to help!

Have Questions? Please Comment below to Solve your Queries! Comments must be Related to the above Topic!!

Subscribe
Notify of
8 Comments
Newest
Oldest
Inline Feedbacks
View all comments


Primary Sidebar

Categories

  • 3-Phase Power (15)
  • 324 IC Circuits (19)
  • 4017 IC Circuits (52)
  • 4060 IC Circuits (26)
  • 555 IC Circuits (99)
  • 741 IC Circuits (20)
  • Arduino Engineering Projects (83)
  • Audio and Amplifier Projects (118)
  • Battery Chargers (83)
  • Car and Motorcycle (96)
  • Datasheets (77)
  • Decorative Lighting (Diwali, Christmas) (33)
  • Electronic Components (101)
  • Electronic Devices and Circuit Theory (36)
  • Electronics Tutorial (120)
  • Fish Aquarium (5)
  • Free Energy (34)
  • Fun Projects (14)
  • GSM Projects (9)
  • Health Related (20)
  • Heater Controllers (30)
  • Home Electrical Circuits (106)
  • How to Articles (20)
  • Incubator Related (6)
  • Industrial Electronics (28)
  • Infrared (IR) (40)
  • Inverter Circuits (98)
  • Laser Projects (12)
  • LED and Light Effect (95)
  • LM317/LM338 (21)
  • LM3915 IC (25)
  • Meters and Testers (67)
  • Mini Projects (152)
  • Motor Controller (67)
  • MPPT (7)
  • Oscillator Circuits (25)
  • PIR (Passive Infrared) (8)
  • Power Electronics (35)
  • Power Supply Circuits (81)
  • Radio Circuits (10)
  • Remote Control (48)
  • Security and Alarm (64)
  • Sensors and Detectors (127)
  • SG3525 IC (5)
  • Simple Circuits (75)
  • SMPS (29)
  • Solar Controllers (62)
  • Timer and Delay Relay (54)
  • TL494 IC (5)
  • Transformerless Power Supply (8)
  • Transmitter Circuits (41)
  • Ultrasonic Projects (16)
  • Water Level Controller (45)

Calculators

  • AWG to Millimeter Converter
  • Battery Back up Time Calculator
  • Capacitance Reactance Calculator
  • IC 555 Astable Calculator
  • IC 555 Monostable Calculator
  • Inductance Calculator
  • LC Resonance Calculator
  • LM317, LM338, LM396 Calculator
  • Ohm’s Law Calculator
  • Phase Angle Phase Shift Calculator
  • Power Factor (PF) Calculator
  • Reactance Calculator
  • Small Signal Transistor(BJT) and Diode Quick Datasheet
  • Transistor Astable Calculator
  • Transistor base Resistor Calculator
  • Voltage Divider Calculator
  • Wire Current Calculator
  • Zener Diode Calculator

© 2023 · Swagatam Innovations

wpDiscuz