ke1

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...

When repairing electronics or circuit boards (PCBs), it's common to encounter screws that are rusted or have damaged heads. This is especially true for devices that have aged or were used in humid environments. If you try to remove such screws forcefully, you might end up damaging the board itself—leading to higher repair costs or irreversible failure. In this post, we'll break down how to safely remove rusted and stripped screws from PCBs . Whether you're a beginner or a seasoned technician, you'll find detailed step-by-step instructions, tool recommendations, and critical safety tips to guide you through the process.     1. Assess the Screw Condition First, check the state of the screw. Determine which of the following situations applies: Partially stripped head : Cross or slot head is rounded but still visible Completely damaged head : Head is broken or worn flat Rust-seized : The screw thread is corroded and stuck in place Proper as...

In woodworking, it's often necessary to find the exact center of a circular piece. Whether you're drilling a hole for a handle, mounting a table leg, or doing circular engraving, an inaccurate center can throw off the entire project.     The Simplest Method: All You Need Is a Square Ruler and a Pencil You don't need any fancy tools. With just a standard carpenter’s square and a pencil, you can accurately find the center of any round wooden piece. This method is simple and effective—perfect for beginners and weekend DIYers. Step-by-Step Guide to Finding the Center Place the round wood piece flat on a level surface. Use the square ruler to draw a straight line across the piece, edge to edge. This should act as a diameter line. Rotate the piece about 90 degrees and draw another straight line. The point where the two lines intersect is the exact center.     Tips for Accuracy Instead of a pencil, use a scribe or aw...

PA (Power Amplifier) equipment generates significant heat during high-power operation. Without a well-designed cooling air duct, internal airflow becomes inefficient, reducing cooling performance and leading to excessive temperature rise that shortens equipment lifespan or causes failures. This article provides a detailed cooling air duct optimization strategy for PA equipment, highlighting key factors to consider during design. Efficient duct design simplifies airflow, minimizes pressure loss, and maximizes the performance of cooling devices. For unmanned PA transmission stations or compact industrial equipment, duct design is critical for cooling efficiency.     Key Considerations for PA Equipment Duct Design Duct cross-sectional area : Ensure sufficient area for airflow (minimum 80mm diameter or equivalent) Minimize curves : Avoid sharp bends and sudden diameter changes that increase air resistance Internal finish : Use smooth internal surfaces...

PA (Power Amplifier) equipment generates significant heat during high-power operation, making cooling systems essential. However, during cooling, moisture in the air can condense, leading to serious damage to internal circuits. The key strategy to prevent this is dew point calculation and monitoring . In this article, we explain the meaning of the dew point, its application to PA equipment, and how to design a smart monitoring system. The dew point is the temperature at which moisture in the air begins to condense into water droplets. When the cooling surface temperature falls below the dew point, condensation occurs. Therefore, dew point management is vital in PA equipment cooling design.     Why Dew Point Management is Critical for PA Equipment Prevent short circuits from condensation : Protect RF modules and PCB circuits Extend equipment life : Prevent corrosion and insulation degradation Enable precise cooling design : Avoid unnecessary overcoo...

PA (Power Amplifier) equipment often operates 24/7, which results in significant power consumption for cooling. Simply adding more air conditioners or fans has its limits and leads to higher electricity bills and maintenance costs. In this article, we’ll explore detailed strategies to improve cooling efficiency and reduce power consumption of PA equipment through a smart cooling system . Smart cooling isn’t just about cooling—it’s about analyzing temperature, humidity, dew point, and load status to provide cooling only when and where it’s needed, saving energy intelligently.     Key Components of a Smart Cooling System Temperature and humidity sensors : Monitor environmental conditions in real time Arduino or Raspberry Pi controller : Collect data and control cooling devices Peltier modules + cooling fans : Apply localized cooling Ducts + forced exhaust fans : Efficiently expel internal heat Smart logic : Automatically adjust cooling output ba...

PA (Power Amplifier) equipment and similar electronics are particularly vulnerable to heat, humidity, and condensation. In environments where Peltier cooling systems or HVAC setups may cause condensation, PCB waterproof coating becomes an essential protective measure. This article provides a detailed guide on the importance of PCB waterproof coating, design considerations, application tips, recommended materials, and best practices for PA equipment. PCB waterproof coating forms a thin insulating layer on the circuit board surface to protect against moisture, dust, and condensation, preventing short circuits and corrosion. In remote-operated transmission sites, industrial control systems, and PA equipment where maintenance access is limited, waterproof coating serves as a critical barrier that extends equipment life.     Why PCB Waterproof Coating is Needed Condensation prevention : Protects against shorts and failures from moisture ingress near cooling ...

PA (Power Amplifier) equipment generates significant heat during long continuous operation. Without effective cooling, this can lead to performance degradation, reduced lifespan, or even equipment failure. This article introduces a detailed strategy for optimizing thermal management of PA equipment by combining a Peltier cooling system with duct design . The focus includes condensation prevention, energy efficiency, and maintenance convenience. A Peltier module cools one side while heating the other when powered. By integrating this with air cooling fans and duct systems in PA equipment, you can achieve both local cooling and forced heat exhaust at the same time.     Peltier + Duct Combined Design Overview The recommended design combination for PA equipment cooling includes: Peltier module (TEC1-12706) : Localized cooling applied to main heat-generating areas of the PA Large heatsink + high-speed fan : Enhanced heat dissipation from the Peltier hot...

The Peltier module is a powerful tool for local cooling of small electronic equipment. However, when injecting Peltier-cooled air into PA (Power Amplifier) equipment, the risk of condensation increases along with the cooling effect. In this post, we will look at how condensation forms inside PA equipment when Peltier-cooled air is injected, based on simulation examples, and introduce key design points to prevent it. Condensation occurs when moisture in the air turns into water droplets on cold surfaces. If the cooled air drops below the dew point, water droplets will form on metal surfaces and circuit boards inside the equipment, potentially causing short circuits, corrosion, and insulation failure. Therefore, condensation simulation and dew point management are essential in the design of cooling air injection systems.     Simulation Conditions for Peltier-Cooled Air Injection Key conditions used in the simulation: Outdoor conditions : 28°C, 70% relat...

One of the biggest concerns when cooling electronic equipment is condensation . Especially when using a Peltier module for cooling, improper design can lead to condensation that damages electronic circuits. In this post, we introduce how to build a DIY smart Peltier controller using Arduino to prevent condensation. The step-by-step explanation is easy to follow, even for beginners. The Peltier module cools one side while heating the other, making it popular in mini coolers, beverage chillers, and optical equipment. However, if the cooled surface temperature falls below the dew point, condensation occurs as moisture in the air turns into water droplets. This condensation can cause serious problems for electronic equipment, so building a smart controller to prevent it is essential.     DIY Smart Peltier Controller Design Overview The DIY smart controller for condensation prevention consists of the following components: Temperature and humidity sensor (...

Condensation is a common phenomenon in our daily lives, and it becomes a major concern when operating electronic equipment or designing cooling systems. In this article, we will explore why condensation occurs, the scientific principle of the dew point, the conditions that cause condensation, and practical methods to prevent it in electronic equipment. Condensation happens when water vapor in the air turns into liquid droplets on a cold surface. This does not occur just because the surface is cold — the air’s temperature and humidity play crucial roles. When these two values reach a certain point, the air can no longer hold moisture as vapor, and condensation begins. This critical temperature is known as the dew point .     The Principle of Dew Point and Condensation Formation The dew point is the temperature at which air at a specific humidity and temperature reaches full saturation and starts to condense water vapor. For example, at 24°C with 60% humidity...

10W-class PA (Power Amplifier) equipment is widely used in small transmission stations, repeaters, and experimental RF systems. Although compact, these devices often operate continuously 24 hours a day, and accumulated heat can lead to performance degradation and reduced lifespan. In this article, we introduce practical design strategies for cooling 10W-class PA equipment, especially how to maximize efficiency by combining air cooling, Peltier modules, and duct systems in parallel operation. The heat generated by PA equipment originates from power loss, with approximately 30–50% of the input power converted to heat. In the case of a 10W output PA, about 10W of heat is continuously produced. If this heat is not efficiently managed, internal temperature rises, leading to issues such as RF performance deterioration, component aging, and condensation.     Parallel Cooling Strategy with Air Cooling, Peltier, and Duct The basic of cooling design is air cooling. P...