As the scope of the Internet of Things (IoT) expands rapidly, the stability of long-term power supply and the reduction of maintenance costs have become critical challenges. In particular, low-power IoT sensors benefit from minimizing battery replacement cycles or even eliminating batteries altogether, which is advantageous both in operational efficiency and environmental sustainability. The technology that makes this possible is Energy Harvesting . What is Energy Harvesting? Energy harvesting refers to the technology of collecting various forms of micro energy available in the surrounding environment and converting it into electrical energy. By transforming sources like sunlight, heat, vibration, and radio waves into operating power for small electronic devices, it enables long-term operation without an external power supply. Main Energy Sources Suitable for Low-Power IoT Indoor Photovoltaic (PV) Provides stable power of 15–35 μW/cm² in office environments with 200–400...

It’s the height of summer, the sun is blazing, and it’s the perfect season for a cool bite of ice cream. Yet surprisingly, recent statistics reveal that the domestic ice cream market has declined by 35% . What’s behind this unexpected drop? In this post, we’ll explore the complex reasons why ice cream sales have plunged despite scorching heatwaves. 1. Sales Volume Falls, Revenue Barely Holds According to the distribution industry, ice cream sales volume fell by as much as 35% in summer 2024 compared to summer 2023. However, total revenue remained relatively stable thanks to higher product prices. In essence, unit prices rose while purchase frequency dropped, showing a clear shift in consumer behavior. 2. Soaring Ingredient Costs, Especially Coconut Oil One of the main culprits is the skyrocketing cost of raw materials . Key ingredients such as coconut oil, milk, and sugar have seen significant price increases in recent years. Since coconut oil is heavily imported, global ma...

Smart keys have become an essential technology to enhance both the security and convenience of vehicles. However, as technology advances, so do the hacking techniques that exploit it. One of the most notorious methods is the relay attack . In this post, we’ll break down what relay attacks are, real-world cases of theft, and practical ways to protect your car from these sophisticated hacks. What is a Relay Attack? A relay attack involves two or more criminals using a wireless repeater to trick your car into thinking the key is nearby. For example, even if the key is inside your house, one attacker places a repeater near your front door while the other stands near your car. The repeater transmits the signal to the car, which mistakenly assumes the key is within range, allowing unauthorized unlocking or ignition Real-Life Cases of Relay Attacks London, UK: Hundreds of BMWs and Mercedes vehicles were stolen in 2020 using relay attack methods. Munich, Germany: ...

1. The Origin of Korean Chinese Cuisine: Gonghwachun in Incheon The root of Korean Chinese cuisine began in 1905 at Gonghwachun , a Chinese restaurant that opened in Incheon. At the time, Chinese immigrants from Shandong settled in Incheon's Chinatown and recreated dishes from their homeland, which gave birth to jajangmyeon . Over the 20th century, it gradually evolved into a uniquely Korean style . 2. Jajangmyeon, a Flavor Not Found in China The original form of jajangmyeon is “zhajiangmian (炸醬麵)” from the Shandong region of China. This Chinese version is a simple mix of stir-fried meat and soybean paste. Korean-style jajangmyeon uses a sauce made with chunjang (a Korean black bean paste) and caramel to create a sweet, rich black sauce, becoming a popular, affordable meal in Korea. 3. Jjamppong: From Japan to Korea The name “jjamppong” is derived from the Japanese “Champon (ちゃんぽん),” which refers to mixing various ingredients in one bowl. However, in Korea, the dish...

A morning salad is a great way to kickstart a healthy day. Especially when you add plenty of protein , it helps with satiety, energy balance, and muscle maintenance. So what are the best protein ingredients to pair with your salad? Chicken Breast: Always a Winner Sliced or cubed chicken breast is rich in protein and low in saturated fat. It’s one of the most popular options. If you prepare it in advance and store it in the fridge, it’s a breeze to use in the morning. Boiled or Soft-Boiled Eggs Eggs are a complete protein food , offering a well-balanced nutrient profile. Adding one or two to your salad provides creaminess and depth. A soft-boiled egg is especially rich and satisfying. Avocado and Cheese Work Beautifully Together Avocados are rich in healthy fats and fiber, but they also contain a small amount of protein. Combine them with cottage cheese or mozzarella to boost flavor and protein content. Don’t Overlook Plant-Based Proteins For those who prefer lighter...

1. The Evolution of Cooking Appliances — What Should You Choose? One of the biggest dilemmas people face when setting up a new kitchen is choosing between an induction cooktop and a gas stove . Each has its own set of strengths and weaknesses, so rather than asking which is “better,” it’s more practical to consider your environment, energy efficiency, and safety . 2. How Induction Works Induction cooktops use electromagnetic induction to heat cookware directly. A high-frequency alternating current flows through coils under the cooktop, generating a magnetic field. This magnetic field creates eddy currents in the bottom of cookware that contains iron. These currents cause the cookware itself to generate heat . Since the surface of the cooktop doesn’t get hot, the risk of burns is reduced and energy is not wasted . 3. How Gas Stoves Work Gas stoves use city gas or LPG to produce a flame that heats the cookware from below. Because the flame is visible, it allows for intuitiv...

    There’s a tiny component found in almost every electronic device we use every day: the capacitor . It stores and releases electrical energy temporarily, playing a vital role in power management and signal integrity. But where did it come from? Today, we’ll explore the invention and evolution of the capacitor from the 18th century to the present.     1. Birth of the Capacitor: The Discovery of the Leyden Jar In 1745, Pieter van Musschenbroek of Leiden University in the Netherlands accidentally invented a device that could store static electricity: the Leyden jar . Using a glass jar filled with water and coated with metal foil, this setup could hold a significant electric charge—becoming the first known capacitor. 2. The Rise of the “Condenser” and Its Role In the 18th and 19th centuries, the term “ condenser ” was used to describe this device because it “condensed” or collected electric charge. It was widely used in sta...

In modern electronic devices, the Switching Mode Power Supply (SMPS) is an essential energy conversion system. One of its most critical components is the switching power controller IC . Among various options, the TOPSwitch series by Power Integrations stands out for its high integration and efficiency. Specifically, the TOP248YN is a widely adopted model for medium- and small-sized power supplies.     This post will explore the internal structure and operation of the TOP248YN and explain how it is applied in real-world circuit designs. 1. Introduction to TOP248YN TOP248YN is a highly integrated switching power solution that combines a PWM controller and high-voltage MOSFET into a single chip. It accepts an AC input of 85–265V and outputs various DC voltages, supporting up to 65W under preheat conditions. Manufacturer: Power Integrations Package: TO-220-7C Built-in functions: high-voltage MOSFET, current limit, oscillator, feedback contro...

Among the essential components in electronic circuits, capacitors always take a prominent place. In particular, electrolytic capacitors are indispensable for power supply and filter circuits. While they don’t appear to directly control current, their role in stabilizing the circuit is critical and often determines the reliability of the entire device.     In this article, we will dive into the structure and characteristics of electrolytic capacitors, and see how they work as the unsung heroes of smoothing circuits. 1. What Is an Electrolytic Capacitor? An electrolytic capacitor is a polarized capacitor that uses an electrolyte, typically consisting of an aluminum anode, an oxide layer, and an electrolyte . This structure allows it to achieve much larger capacitance compared to other types of capacitors, all within a relatively small package. On the downside, it has polarity , meaning it must be connected correctly, or it risks failure or even explos...

When you open up an electronic device, you might come across a small cylindrical or rectangular component labeled “F1.” That tiny part is a fuse . Although it may look insignificant, a fuse plays a vital role—it acts as the first line of defense to protect your device when excessive current flows through the circuit.     In this post, we'll explore why fuses are essential, how they work, and how they fit into the overall overcurrent protection structure in electronic devices. 1. What Is a Fuse? A fuse is a protective device that interrupts the electrical circuit when the current exceeds a certain limit. It contains a metal wire or strip that melts when too much current flows through it, breaking the circuit and preventing further damage. The operation is simple: when overcurrent occurs, the metal heats up, melts, and disconnects the power flow. This quick response prevents components from overheating or catching fire. 2. Why Is a Fuse Absolutely Neces...

In a typical power supply circuit, the bridge rectifier plays a central role. It converts alternating current (AC) into direct current (DC), allowing stable and consistent power delivery to electronic components. In particular, the integrated bridge rectifier module simplifies circuit design by consolidating four diodes into a single package.     1. What Is an Integrated Bridge Rectifier? An integrated bridge rectifier module is a component that combines four diodes into one compact package. It features four terminals: two for AC input and two for DC output. The main advantage is its ease of use and reduced soldering points on the PCB. 2. Advantages of Using a Bridge Rectifier Module Compact Design: Reduces the area needed on the circuit board. Simplified Assembly: Easier soldering with fewer connections. Enhanced Reliability: Pre-tested components minimize errors.     3. Pinout and Structure Bridge rectifier modules usua...

Thermistors may be small, but their role in electronic circuits, especially power supply boards, is massive. Among them, NTC (Negative Temperature Coefficient) thermistors are frequently used as inrush current limiters. This post walks you through how NTC thermistors work, why they’re wired in series with hotlines, and how to test or diagnose them.     What Is an NTC Thermistor? An NTC thermistor is a temperature-sensitive resistor that decreases its resistance as temperature increases. When cold, it provides high resistance; as it heats up (due to current flow), its resistance drops, allowing higher current to flow safely into the circuit. This makes it perfect for power-up scenarios where large capacitors or switching components could otherwise cause a surge. Why Is It Wired in Series on the Hot Line? The primary role of an NTC thermistor in a power circuit is inrush current suppression. It is always installed in series with the AC input "hotline." On s...

An NTC (Negative Temperature Coefficient) thermistor is an essential component used in the power supply section of electronic devices. It is commonly connected in series with the AC input line and is responsible for suppressing inrush current at the moment of power-up.     Structure and Principle of NTC Thermistor An NTC thermistor consists of a semiconductor ceramic element whose resistance decreases as the temperature rises. At room temperature, it maintains high resistance, limiting the inrush current when power is first applied. As the device warms up, the resistance rapidly drops, allowing stable current flow with minimal power loss. Main Functions of NTC Thermistor Suppressing inrush current: protects bridge diodes and capacitors from surge damage Gradual startup of power supply: ensures smooth charging of electrolytic capacitors Thermal protection: can act as a safety element if placed near heating elements     ...

Interest in digital currencies is rapidly growing worldwide. Among them, Central Bank Digital Currencies (CBDCs) are attracting the most attention from governments and financial institutions. In this post, we’ll explain what a CBDC is and how it differs fundamentally from cryptocurrencies like Bitcoin.     What Is CBDC? CBDC stands for Central Bank Digital Currency. It is a digital version of legal tender issued by a country's central bank. Like physical cash (banknotes and coins), CBDC is backed by the government, but it exists in digital form, often operating on blockchain or centralized databases. For instance, a CBDC issued by the Bank of Korea would carry the same legal value as Korean won and can be used for sending, receiving, and making payments via digital wallets. CBDC vs. Cryptocurrency: What's the Difference? Many people confuse CBDCs with cryptocurrencies. However, they are completely different in philosophy, structure, and function. ...

If your skin becomes itchy or red after just a few minutes in the sun, it might not be simple sensitivity. It could be photosensitivity —an abnormal reaction to UV rays. When left unchecked, this condition can greatly affect your daily life. In this blog, we explain how photosensitivity is diagnosed and what to consider when choosing a dermatology clinic .     Common Symptoms That May Suggest Photosensitivity Unlike basic sun irritation, photosensitivity usually appears suddenly and can recur regularly. Here are the telltale signs: Itching, redness, or blisters within hours of sun exposure Burning or stinging sensation on exposed areas Symptoms appear only on sun-exposed skin (face, arms, neck, etc.) Worsening reactions after taking certain medications If these symptoms occur repeatedly, you should consider being tested for photosensitivity rather than assuming it’s just mild irritation. How Do Doctors Diagnose Photosensitivity? Photo...

You never had skin issues before, but now, sunlight exposure suddenly causes redness, itching, and stinging. If this started happening after the age of 50, it might not just be a sunburn—you're likely experiencing photosensitivity or a sun allergy . Sun allergies that emerge after 50 are often triggered by a combination of factors such as immune system shifts, medications, skincare ingredients, or hormonal changes. In this post, we’ll dive into the causes, symptoms, and effective prevention strategies for managing sun allergies in your 50s and beyond.     Main Causes of Sun Allergy After 50 Weakened immune response: As we age, immune regulation declines, making skin overreact to external stimuli like UV rays. Medications: Drugs for hypertension, diabetes, or cholesterol can cause photosensitive reactions when combined with sunlight. Thinner skin barrier: Hormonal shifts during menopause or andropause reduce skin’s natural defenses. Skincare ...

If you had to choose just one product for dry seasons or irritated skin, many people would instantly pick Vaseline . For over 150 years, Vaseline has been loved worldwide not just as a moisturizer, but also as a versatile item with various uses and DIY potential. In this article, we'll explore its ingredients, benefits, usage tips, precautions, and creative applications.     What Is Vaseline? Vaseline is a brand name for a product made of 100% refined petroleum jelly (Petrolatum) . Derived from crude oil, it's a semi-solid substance that undergoes multiple purification processes to make it safe for skin. It forms a thin protective layer over the skin, preventing moisture loss and shielding it from external irritants. How It Differs from Regular Moisturizers The key difference between Vaseline and regular moisturizers lies in their moisturizing mechanisms. Vaseline is an occlusive agent—it works like a lid, locking in moisture by sealing the skin. In c...

In recent years, EGF (Epidermal Growth Factor) has gained popularity in skincare due to growing interest in skin regeneration and anti-aging. While advertisements often tout EGF as a miracle ingredient, does it actually work? In this post, we’ll explore what EGF is, how it works, its clinical efficacy, and key points to consider when choosing EGF-containing skincare products.     What Is EGF? EGF stands for Epidermal Growth Factor , a naturally occurring protein in the body that promotes cell growth, differentiation, and regeneration . Initially used in medical fields such as burn treatment and post-surgery recovery, its ability to promote skin healing has led to its adoption in the cosmetic industry. How Does EGF Work on Skin? When applied to the skin, EGF sends signals to epidermal cells to accelerate their division and renewal. It enhances collagen synthesis , improves skin elasticity , reduces fine lines and wrinkles , and speeds up the healing proc...