How to Properly Handle LEDs for Beginners The Beginner's Tutorial If you watch my videos, then you know I love LEDs - like every second video involves them. But there's been some questions and comments on how to use them properly, and sometimes I don't even handle them the correct way. So today, I will tell you how easy it can be and how difficult it can get to handle LED properly. First of all, when you buy your LEDs on Amazon or eBay or elsewhere, often there exists no datasheet for them, which is a shame. But there are two important parameters that are always given: the forward voltage, which is 3.2 volts, and the current they need to light up ideally, which is 20 milliamps. Now you've got your power source, for example, a 12-volt acid battery or button cells, or in my case, a 9-volt battery. The simplified circuit to light up an LED looks like this: If we would not use a resistor, the LED would die faster. Then you can say well, what value does the resistor need? Kirchhoff's voltage law gives the answer: the voltage sum in a closed network must be zero. On the left side is the voltage of our power source, and on the right side is the voltage of our load. I think everyone sees that the voltage of the resistor must be 5.8 volts to solve the equation. Then you can just calculate the value for the resistor by Ohm's law: resistance equals voltage divided by current. Since the LED and resistor are connected in series, the 20 milliamps will also flow through the resistor, so 5.8 volts divided by 0.02 amps equals 290 ohms. Two of those 150-ohm resistors in series will work fine when you don't have the correct value. Then use a bigger one, like I did with 300 ohm. Another rating for the resistor is power. Those are a quarter-watt resistors. We heat them up with a power of 5.8 volts multiplied by 0.02 amps, which equals 0.116 watts. Since 0.116 watts is smaller than 0.25 watts, everything is fine. If you overload your resistor, then it might look somehow like this: Now you want to light up two of your LEDs. You could build the same resistor-LED combination in parallel, but that is a waste of power. Just put the two LEDs in series and repeat the same calculation process. This time we only have a voltage drop of 2.6 volts across the resistor, a resistor value of 130 ohms, and the power loss of 0.052 watts. We got twice the light and half of the wasted power. That is awesome! But we do not have enough voltage to put three in series. The LEDs will be darker this way, which brings us to the advanced territory. First of all, never trust the manufacturer. It says 3.2 volts, but that's not always true. But there are two important parameters that are always given: the forward voltage and the current they need to light up ideally. Let's take a look at the datasheet of the LED we are using. As you can see, the forward voltage is 3.2 volts, but that's not always true. The current they need to light up ideally is 20 milliamps. Now let's talk about constant current mode. This is actually the best way to drive LEDs. You can build a simple constant current source with a LM317 and a resistor. Here's the schematic: Even though this works, the efficiency is quite horrible. The TLC5940 is also a popular example of a constant current driver. But this will be a subject in another video. For now, I hope you liked the subject. Please support my videos by sharing them and please don't forget to like. Stay creative, and I will see you next time! LED Tutorial An LED (Light Emitting Diode) tutorial is an educational resource that provides a comprehensive guide on how to work with LEDs, including their basics, characteristics, and applications. The tutorial typically covers topics such as the history of LEDs, types of LEDs, LED circuitry, LED drivers, and LED projects. Background The use of LEDs dates back to the 1960s when they were first introduced as low-intensity infrared devices. Over time, LEDs evolved to become high-brightness visible devices used in a wide range of applications, including lighting, displays, and indicators. Today, LEDs are an essential component in many modern technologies, from smartphones to automotive systems. How to Properly Handle LEDs for Beginners Introduction LEDs (Light Emitting Diodes) are a popular choice for many applications due to their energy efficiency, long lifespan, and versatility. However, handling LEDs requires some care to ensure they function properly and last as long as expected. In this article, we will guide beginners on how to properly handle LEDs. Understanding LED Basics Before handling LEDs, it's essential to understand their basic components and characteristics. An LED consists of a semiconductor material, electrodes, and a transparent plastic or epoxy resin casing. LEDs are sensitive to heat, moisture, and electrical stress. Handling Precautions To prevent damage and ensure safe handling, follow these precautions:   Avoid touching the LED's electrical contacts or pins. Handle LEDs by their edges or casing to prevent damage from static electricity. Use an anti-static wrist strap or mat when handling LEDs. Avoid exposing LEDs to extreme temperatures, moisture, or direct sunlight. Soldering and Desoldering When soldering or desoldering LEDs, follow these guidelines:   Use a low-wattage soldering iron (15-30W) to prevent overheating the LED. Apply a small amount of solder and avoid touching the LED's electrical contacts. Desolder LEDs carefully, using a desoldering wick or pump, to avoid damaging the surrounding components. Storage and Transportation To maintain LED quality during storage and transportation:   Store LEDs in their original packaging or anti-static bags. Keep LEDs away from direct sunlight, moisture, and extreme temperatures. Transport LEDs securely, using protective materials like bubble wrap or foam inserts. Conclusion Proper handling of LEDs is crucial to ensure their reliability and performance. By following these guidelines, beginners can minimize the risk of damage and maximize the lifespan of their LEDs. Q1: What is the most important thing to consider when handling LEDs? A1: Static electricity. LEDs are highly sensitive to static electricity, which can damage or destroy them. Q2: How should I store my LEDs when not in use? A2: Store your LEDs in an anti-static bag or wrap them in anti-static material to protect them from static electricity. Q3: Can I touch the leads of an LED with my bare hands? A3: No, it's recommended to handle LEDs by the body or the epoxy resin, avoiding contact with the metal leads to prevent static electricity damage. Q4: How do I properly handle an LED when soldering? A4: Use a well-ventilated area, avoid breathing in fumes, and use a temperature-controlled soldering iron to prevent overheating the LED. Q5: Can I bend or flex an LED's leads? A5: Yes, but be gentle and avoid excessive bending or flexing, as this can cause mechanical stress and potentially damage the LED. Q6: How do I clean my LEDs? A6: Use a soft brush or a cotton swab with a mild detergent solution to gently remove dirt or debris from the LED's surface. Q7: Can I use any type of solder when working with LEDs? A7: No, use a lead-free solder (such as SAC305) and avoid using acid-core or flux-based solders, which can damage the LED. Q8: How do I properly dispose of used LEDs? A8: Dispose of used LEDs through a reputable electronics waste recycling program to prevent environmental harm. Q9: Can I use an LED in extreme temperatures? A9: No, most LEDs have operating temperature ranges (usually between -20°C and 80°C). Using them outside these ranges can cause damage or affect performance. Q10: How do I check if an LED is damaged? A10: Visually inspect the LED for signs of physical damage, and use a multimeter to test its forward voltage drop (Vf) and current draw. Pioneers/Companies Description Nichia Corporation Developed the first high-brightness blue LED in 1994, revolutionizing the industry. Cree Inc. Pioneered the development of high-power LEDs and introduced the first commercially available white LED in 2001. Osram Opto Semiconductors Introduced the first high-brightness LED with a luminous flux of 100 lumens in 1999, setting a new standard for the industry. Lumileds (Philips) Developed the Luxeon LED, one of the first high-power LEDs on the market, and introduced it in 1998. Toshiba Released the first white LED with a luminous efficacy of over 100 lumens per watt in 2007. Seoul Semiconductor Introduced the world's first 3W high-power LED in 2005, setting a new benchmark for LED performance. Everlight Electronics Developed the first high-brightness LED with a luminous flux of over 1000 lumens in 2011. Bridgelux Introduced the first commercially available LED array with integrated optics in 2007, enhancing LED performance and efficiency. LG Innotek Developed the world's first high-brightness LED with a luminous efficacy of over 150 lumens per watt in 2013. Samsung Electronics Released the first LED module with a luminous flux of over 2000 lumens in 2014, pushing the boundaries of LED performance. Section Description Technical Details Handling LEDs Proper handling techniques to prevent damage and ensure longevity. Avoid touching the LED's leads or body, as oils from skin can cause corrosion. Use tweezers or a vacuum pickup tool to handle LEDs. Store LEDs in anti-static packaging or bags to protect against electrostatic discharge (ESD). Static Protection Measures to prevent damage from static electricity. Use an anti-static wrist strap or mat when handling LEDs. Ensure the work surface is grounded and use a humidifier to maintain a relative humidity of 40-60% to reduce static buildup. Use ESD-safe tools, such as stainless steel or conductive plastic, when handling LEDs. Soldering Techniques Best practices for soldering LEDs to prevent damage and ensure reliable connections. Use a temperature-controlled soldering iron with a tip temperature of 350-400°C (662-752°F). Apply a small amount of flux to the LED's leads and the PCB pads. Use a solder with a low melting point (e.g., Sn96.5Ag3Cu0.5) and avoid overheating or applying excessive force, which can cause damage to the LED. Current Limiting Understanding current limiting requirements for LEDs to prevent overcurrent conditions. Use a series resistor (R) or a constant current source to limit the current to the LED's maximum rated value. Calculate R using the formula: R = (V_supply - V_LED) / I_LED, where V_supply is the supply voltage, V_LED is the LED's forward voltage drop, and I_LED is the desired LED current. Thermal Management Techniques for managing heat generated by LEDs to prevent overheating and ensure reliability. Use a thermal interface material (TIM) between the LED and the heatsink or PCB. Ensure adequate airflow around the LED using fans or ventilation holes. Use a thermistor or temperature sensor to monitor the LED's temperature, and adjust the current or add cooling as needed.