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What Is a Microwave Absorber?

Radar absorbent material (RAM) is a material that absorbs incident radio waves and suppresses their reflection. It is also called a radio wave-absorbing material. The energy of incident radio waves is converted into heat energy and consumed.

Several types of Microwave Absorbers have different principles of absorbing radio waves depending on the material and shape. The frequency band that can be absorbed differs depending on the type. Therefore, it is necessary to select a Microwave Absorber that matches the application and design it appropriately.

Uses of Microwave Absorbers

The main applications of Microwave Absorbers include noise suppression for electronic devices such as communication equipment and home appliances, anti-reflection for ETC and radar, and evaluation facilities such as anechoic chambers. Microwave Absorbers with characteristics suited to each application are used.

For electronic equipment, a sheet type is used that can shield against specific frequencies emitted by the electronic equipment and can be incorporated into the electronic equipment. On the other hand, for evaluation facilities such as anechoic chambers, Microwave Absorbers in a three-dimensional pyramid shape are used, which have absorption characteristics over a wide frequency band.

Principles of Microwave Absorbers

There are several types of Microwave Absorbers depending on the principle of absorbing radio waves, and the three main types are resistive, inductive, and magnetic.

The resistive type absorbs the energy of radio waves by converting the induced current generated by the incident of radio waves on the conductor into heat energy by consuming it due to the conductor’s own resistance.

The dielectric type uses the resistance component of the carbon particles themselves and the capacitance component between the carbon particles by mixing carbon particles with a dielectric such as foamed polyethylene or rubber. When the incident radio wave is low frequency, almost no electric current is generated. However, as the frequency increases, the impedance of the capacitance component decreases, and an electric current flows. The higher the frequency, the lower the impedance of the capacitive element. The higher the frequency, the more current flows, consumed by the resistor and converted into heat energy to absorb the radio wave energy.

Dielectric types are available in pyramid or sheet forms, depending on their shape. The pyramid type can be designed to absorb a wide range of frequencies because the frequency band to be absorbed is determined not only by the material mixed in but also by its shape.

The magnetic type is made of ferrite or other magnetic materials molded into tile-like shapes, which absorb radio wave energy through magnetic loss. The magnetic type can provide absorption characteristics in the low-frequency band compared to the dielectric type. For this reason, Microwave Absorbers have a wide frequency range by combining dielectric and magnetic types.

Other absorbers have a phase difference of 180 degrees concerning the incident wave to cancel out the reflected wave.

What Is a Power Meter?

A power meter is a device used to measure the power consumed by electrical and electronic equipment, also known as loads.

A power meter is inserted between a power source and a load to calculate power from the product of the applied voltage and the flowing current (voltage x current). In AC (alternating current), a phase difference between voltage and current affects the power calculation, making simultaneous measurement essential.

Recently, the quality of the power supply has become a crucial concern, with some meters featuring functions to evaluate the waveforms of voltage, current, and power.

Uses of Power Meters

With the rising importance of reducing energy consumption to address global environmental issues, there’s an increasing need for power meters to monitor the power consumption of various electrical and electronic equipment. Their applications range from electricity saving in households to power monitoring systems in factories and buildings. Highly accurate and sophisticated power meters are also vital for assessing phase angle, power factor, harmonics, flicker, distortion, noise, etc., in development and production environments.

Principle of Power Meters

Electric power, the product of voltage and current, is calculated by measuring these two parameters. For direct current, where both are constant, power calculation is straightforward. However, in alternating current, the phase difference between voltage and current requires continuous measurement of their instantaneous values at the same time.

The power consumed by the load, known as effective power, is the integration and average of the instantaneous power over one cycle. Effective power can be calculated as V × I × cos(θ), where V is the effective voltage, I is the effective current, and θ is the phase difference between voltage and current.

AC power calculations also include reactive power and apparent power, essential for evaluating the efficiency and stability of power supply systems, especially in industrial and utility settings. The power factor, the ratio of active to reactive power, is a key metric for efficiency improvement strategies.

Reactive Power

Generated by the phase difference between current and voltage, reactive power oscillates between the power source and the equipment, influenced by the inductive and capacitive components of the load, and is calculated as V x I x sin(θ).

Apparent Power

Representing the actual flow of current and voltage in a system, apparent power’s equation is the square root of the sum of active power squared and reactive power squared.

How to Select a Power Meter

1. Check the Type of Measurement Target and Required Accuracy

Identify the measurement target (power, current, voltage, power factor, etc.) and the required accuracy, as the measurement range and resolution vary by application.

2. Selecting the Type of Power Meter

Power meters come in analog and digital forms. Analog meters display instantaneous values, while digital meters offer digital displays and data logging capabilities. Choose based on use, environment, and readability.

3. Power Factor and Accuracy Considerations

Evaluate the power factor and accuracy of the power meter, selecting products that maintain a high power factor.

4. Check Communication and Data Collection Capabilities

Modern power meters often feature communication interfaces (like Modbus or Ethernet) and data acquisition capabilities, essential for real-time data collection or remote monitoring.

What Is a Trimmer Potentiometer?

A trimmer potentiometer is a variable resistor whose resistance value can be changed.

They are also called trimmer resistors or trim potentiometers because of their role in adjusting (trimming) the resistance value of a circuit in an electronic device. They adjust for variations due to individual differences in other electronic components.

The resistance of a trimmer potentiometer is adjusted by turning a knob with a driver. There are two types: top-turned and side-turned, and single-turn and multi-turn knobs.

Applications of Trimmer Potentiometers

Trimmer potentiometers are used in a variety of products, including communications equipment, measuring instruments, medical equipment, audiovisual equipment, office equipment, and general electronic equipment. They are applied in situations such as post-production timing adjustment, temperature adjustment, and display brightness adjustment.

Typically, once set, they operate as fixed resistors without being seen by the end user, but they may need to be readjusted during maintenance.

Trimmer potentiometers are often used in hobbyist electronics work, as they are useful for fine-tuning circuit boards.

Principle of Trimmer Potentiometers

The principle of the trimmer potentiometer is simple. When voltage is applied to both terminals (terminals 1 and 3) of a resistive element, the physical position of the contacts (slider or wiper) that move on the resistive element changes the resistance between terminals 2 and 1 (or 3), which is connected to the slider.

A trimmer potentiometer has two roles. Voltage adjustment, in which a larger voltage is lowered to obtain the required voltage. And current adjustment, in which the resistance value is adjusted to change the current value.

When used for voltage adjustment, a trimmer potentiometer is used as a 3-terminal element: voltage is applied between terminals 1 and 3, and the voltage divided by the voltage is taken from terminal 2.

When used for current regulation, a trimmer potentiometer is used as a 2-terminal element, and voltage is applied between terminals 1 and 2 to regulate the current. However, it is safe to leave the unused No. 3 terminal open and connect it to the No. 2 terminal.

The resistance between the two ends of a trimmer potentiometer and the total resistance vary. If the total resistance value is small, the variable range becomes narrower. On the other hand, if the total resistance value is large, the variable range becomes large. However, the setting accuracy becomes lax. Generally, a trimmer potentiometer is selected so that adjustment can be made over a variable range of half the total resistance.

What Is an Emergency Stop Switch?

An emergency stop switch is a critical safety device designed to halt equipment operations in emergencies, protecting against serious accidents and injuries. These switches are essential in environments where industrial machinery operates under high torque or pressure, posing risks to human safety.

Uses of Emergency Stop Switches

These switches are commonly found in machinery such as conveyors, presses, and welding robots, where there’s a risk of entrapment or pinching. Regulations often mandate their installation on equipment like conveyor belts to prevent entrapment accidents. Pull-rope switches are preferred in some cases for their accessibility along the length of a conveyor.

Principle of Emergency Stop Switches

• Push-Button Type: Typically red for visibility, these switches lock when pressed to ensure machinery remains halted until manually reset. They’re designed to interrupt electrical circuits to stop equipment immediately.
• Pull-Rope Type: Used around conveyors, pulling a wire attached to the switch stops the machine. Like push-button types, these switches lock upon activation and require manual resetting.

Other Information on Emergency Stop Switches

• Installation Considerations: The placement of emergency stop switches is crucial for easy access by workers. In large facilities, multiple switches are installed to ensure availability in any emergency.
• Lockout Mechanism: To prevent accidental restarts that could lead to injury or death, some emergency stop switches feature a lockout mechanism. This allows the switch to be padlocked, ensuring that equipment cannot be restarted until it’s safe to do so.

What Is an Indicator?

Indicators display the status of devices and other equipment using light. Generally, the term “indicator light” refers to electric indicators.

The history of indicators in the pure sense is long. Lighthouses are the oldest indicators in the sense that they were used to indicate navigation routes. They were in use as early as BC. Modern electric indicators began to be used in the 20th century and have become an indispensable part of daily life and industry.

The mechanism of indicator lamps has changed over time, from flames made from burning combustible materials to gas lamps, etc. Today, most indicator lamps are electric.

Usage of Indicators

The most typical indicators that everyone has seen are probably traffic signals. These lights are used to indicate that traffic is allowed to pass in green, proceed with caution in yellow, and not allowed to pass in red. Another familiar example is the rotating indicators on fire trucks and police cars. 

Rotating indicator lamps and operating status indicator lamps are also used in production sites in a wide range of applications.

Principle of Indicators

The principle of operation of indicator lamps has changed from the past to the present.

In the past, indicator lamps were made of bean bulbs. A miniature light bulb is a glass shell containing a light-emitting filament and an inert gas. When an electric current flows through the luminous filament, it produces heat and light at the same time. The bean bulb is covered with colored glass or resin to display a specific color. Bean bulbs have the disadvantage that if the inert gas inside is removed, the filament burns out or otherwise malfunctions. In the rotating indicator light, a motor for rotation is used at the same time as the bean bulb. The motor rotates the reflector so that it circles the light bulb to attract attention. While rotating indicators are more conspicuous than ordinary indicators, they have the disadvantage of requiring more parts due to the built-in motor.

Currently, LED indicators are the mainstream choice, as LEDs are diodes that emit light when voltage is applied, and unlike filaments, they generate little heat, resulting in long life and high efficiency. In recent years, LED indicators that blink repeatedly have been sold in place of rotating lights.

What Is a Wireless Modem?

A modem is a word coined from the initial letters of modulator and demodulator and generally refers to a device that mutually converts analog signals on coaxial cables or telephone lines into digital signals for computers and smartphones.

A wireless modem is a device that uses wireless communication as the transmission path for the modem’s line, instead of wired lines such as optical or telephone lines.

Wireless modems have become popular in recent years because people who move frequently do not need to re-contract their Internet connection with each move.

Uses of Wireless Modems

Business people often use wireless modems to connect to their computers and access the Internet on business trips or at home. Among the most popular general-purpose wireless modems are recent small USB-type modems that can be connected to a PC and then used to wirelessly connect to broadband Internet with a base station.

Currently, Wi-Fi communication is the most common, as well as 4G (LTE), 5G, and other mobile terminal communication standards.

Principle of Wireless Modem

The operating principles of modulation and demodulation, which are the main roles of a modem, are explained below:
Modulation refers to the conversion of a digital signal into an analog signal. Specifically, this is the operation of putting digital information onto an analog signal by placing signal amplitude and phase information on a carrier wave (carrier).
Demodulation, conversely, is the process of extracting the desired digital information from the carrier.

The types of wireless communication used for carriers include 3G (WCDMA) and 4G (LTE), which are the communication standards for mobile terminals, and 5G, which is now becoming the mainstream communication standard.

Wi-Fi operates on carrier frequencies in the 2.4GHz and 5GHz bands, which are the main communication standards for wireless LAN. Although the 5GHz band offers the most stable communication, it is usually shared with the 2.4GHz band (which can fly farther due to its shorter range and susceptibility to obstacles).

There are also packet communications, specific amateur radio communications, and other low-power radios such as the ISM band (2.4GHz).

What Is a CCFL Lamp

A CCFL Lamp is a fluorescent lamp, shortened for Cold Cathode Fluorescent Lamp.

While ordinary fluorescent lamps heat their filaments to emit thermal electrons, cold cathode tubes emit electrons without heating their electrodes. Therefore, cold cathode tubes operate at lower temperatures and have a longer life.

In addition, since there is no need to build a filament into the tube, the tube can be made thinner. Fluorescent lamp tubes range in diameter from 15 to 38 mm, while cold cathode tubes are 3 to 5 mm in diameter.

CCFL Lamps cannot be used with standard 50 or 60 Hz commercial AC and require a dedicated power supply that provides high-frequency power.

Applications of CCFL Lamps

CCFL Lamps have more than 30 years of history and have long been used for LCD backlighting, advertising signboards, guide lights, and lighting because of their easy dimming, energy savings, and long life.

In recent years, there has been a shift from CCFL Lamps to LEDs due to the superiority of LEDs over the advantages of cold cathode tubes. LEDs have already completely replaced LCD backlights, and an increasing number of manufacturers are discontinuing the production of cold cathode tubes.

However, CCFL Lamps have advantages not found in LEDs, such as the ability to diffuse light over a wide area and output even, even light, and the ability to produce eye-friendly white light that is close to natural light.

Principle of CCFL Lamp

A CCFL Lamp consists of a long, thin glass tube filled with argon gas and mercury vapor, phosphor coated on the inner wall of the glass tube, and electrodes placed at both ends of the glass tube.

The basic principle of operation of a CCFL Lamp is the same as that of a general fluorescent lamp: electrons emitted from the electrodes combine with mercury ions filled in the glass tube to emit ultraviolet radiation, which excites the phosphor on the inner wall of the tube to emit visible light.

The only difference is the method of electron emission. While ordinary fluorescent lamps emit thermal electrons by passing an electric current through a filament coated with electron-emitting material, CCFL Lamps emit secondary electrons by ion bombardment of argon.

When a high voltage is applied to the metal electrodes of a CCFL Lamp, electrons in the tube are pulled by the positive electrode and move within the electric field, colliding with argon. The argon cations ionized by this collision collide with the negative electrode, emitting secondary electrons.

Since a high voltage must be applied to the CCFL Lamp to emit secondary electrons, an inverter circuit is used as the power supply.

What Is a Color Sensor?

A color sensor is a specialized device designed to accurately distinguish the colors of objects.

It operates by detecting the wavelength and color of light reflected from or transmitted through objects, converting this optical information into electrical signals. Typically, color sensors are used to analyze reflected or transmitted light from a light source, providing precise color or light-related data.

Color sensors are renowned for their ability to deliver highly accurate color measurements. They excel at detecting even subtle color changes or anomalies, making them invaluable for quality control and optimizing manufacturing processes. Furthermore, their real-time color processing capabilities make them well-suited for high-speed production lines and various application systems.

An important advantage of color sensors is their non-contact operation. In industrial manufacturing, this feature minimizes the impact on product quality.

However, it’s essential to note that ambient lighting conditions can significantly affect color sensor performance. Variations in lighting type and intensity can lead to fluctuations in measurement results, underscoring the importance of maintaining appropriate lighting conditions.

Uses of Color Sensors

Color sensors find applications in diverse fields where precise color detection is essential. Here are some notable examples of how color sensors are utilized:

1. Manufacturing Industry

In the manufacturing industry, color sensors play a pivotal role in quality control. For products with painted surfaces, color sensors assess the color of the paint to ensure it matches the specified color. This consistency is crucial for delivering high-quality products that meet customer expectations.

Color sensors are also frequently employed in the production of molded plastic items to verify color consistency. Additionally, they are integral in the display manufacturing sector, where they analyze ambient light to correct display colors and enhance image quality on devices such as smartphones and tablets.

2. Medical Applications

In the medical field, color sensors serve multiple purposes. They are used to measure skin color and blood oxygenation levels. Changes in skin color can be indicative of circulatory disorders or skin conditions, making color sensors valuable diagnostic tools.

Furthermore, in dentistry, color sensors are used to measure and match tooth color. This is particularly useful for aesthetic treatments and ensuring proper color matching for dental prosthetics.

3. Printing Industry

The printing industry relies heavily on color sensors for quality control. These sensors are essential for maintaining color consistency in printed materials.

Color sensors integrated into printing presses continuously monitor the color of printed materials and make real-time color adjustments as needed. This process enhances color reproduction and ensures consistency across different print jobs.

Principle of Color Sensors

The core principle behind color sensors involves illuminating objects with red, blue, and green light and detecting which wavelengths of light are absorbed and to what extent. When red, blue, and green light are directed at a red object, such as an apple, only the red light is reflected, while the blue and green light is absorbed.

Consequently, only the reflected red light reaches our eyes, causing the apple to appear red. Conversely, when all three colors of light strike a white object, all wavelengths are reflected, resulting in the object appearing white.

The internal structure of a color sensor can be broadly divided into three components: the light emitter, the light receiver, and the processing circuit. The light emitter emits light onto the object under examination to gauge the intensity of reflected light.

The ratio of red, blue, and green light detected by the light receiver is employed to determine the color. The light-receiving component converts this ratio into an electrical signal, which is then processed by the circuitry for color identification.

How to Select a Color Sensor

When choosing a color sensor, it’s essential to consider various factors to ensure it suits the intended application. Key considerations include:

1. Detection Distance

The detection distance of a color sensor represents the maximum range at which the sensor can accurately detect colors. Selection should align with the specific requirements of the application, with longer detection distances being necessary for covering larger areas.

2. Output Type

Color sensors offer different output types, including analog and digital signals. Analog output provides continuous measurement data, while digital output switches signal when a predefined threshold is reached. Additionally, some color sensors offer serial communication outputs. The choice depends on the application’s needs.

3. Connection Method

Consider the connection method between the color sensor and the control device. Common connection options include connectors, terminals, and others. Opt for a method that seamlessly integrates with the control device.

4. Protective Structure

For environments with specific requirements, the protective structure of a color sensor is crucial. Factors like dustproof and waterproof capabilities are often indicated by IP codes, which consist of two numbers, with the first denoting dustproofness and the second indicating waterproofness.

What Is an EDA Tool?

An EDA (Electronic Design Automation) tool is a set of software and hardware tools used to streamline and automate the electrical design process.

It can be thought of as the electrical design counterparts to the CAD and CAM tools commonly used in mechanical design.

For instance, in the design of household appliances, the product design journey typically begins with system (conceptual) design, followed by circuit design, assembly, iterative prototyping, and final product completion. Throughout this process, EDA tools play a crucial role in facilitating product design.

Applications of EDA Tools

EDA tools cater to various stages of the design process. In the context of product design, including household appliances, they encompass tools for system (conceptual) design and simulation, which represents the initial design phase. Additionally, they encompass tools for circuit design and simulation, tools for printed circuit board layout, and tools for mitigating unwanted emissions.

In the semiconductor design field, EDA tools encompass tools for semiconductor device design and their simulation, logic and timing design tools and simulation tools, as well as layout design tools and simulation tools.

Principles of EDA Tools

It is technically possible to proceed with product design without employing EDA tools or by using only a subset of these tools.

However, in today’s competitive landscape, where manufacturers of various products, including household appliances and semiconductor devices, vie on a global scale, the notion of “build it, and it will sell” no longer applies. Success hinges on the ability to swiftly and cost-effectively deliver high-functionality, high-performance products. Consequently, circuits are becoming increasingly compact, smaller in size, lighter, and more power-efficient.

Remaining competitive necessitates an unmatched blend of development prowess and speed in this environment, and EDA tools serve as invaluable aids in achieving this.

The initial step in designing a product entails defining the product’s nature. What functions should it encompass? What should the production cost be? Subsequently, one must devise a system configuration that aligns with this cost target.

System design tools prove to be invaluable in this process. The simulation functionality of system design tools enables the evaluation of whether the virtual system configuration, conceived on a computer, is optimal. This involves assessing whether the performance, functionalities, and costs meet predefined expectations.

If simulation results prove unsatisfactory, the system can be reconfigured, and simulations rerun, iterating the trial-and-error process until an optimal system configuration is attained. Conducting this process by physically building a product would entail significant time and resources, but EDA tools empower users to conduct such verifications swiftly on a computer.

A similar approach can be employed in subsequent design phases, effectively shortening the overall design timeline.

What Is an Audio Analyzer?

An audio analyzer is a sophisticated instrument designed to measure various sound parameters such as distortion rate, frequency response, and signal-to-noise ratio, facilitating the quantitative evaluation of sound quality performance. It integrates the functions of a low-distortion oscillator, filter, and frequency counter into a single device, simplifying the process of assessing sound quality.

With advancements in technology, applications that leverage a personal computer for measuring distortion rates have also become available.

Uses of Audio Analyzers

Audio analyzers are pivotal in assessing the sound quality of audio amplifiers, systems, and other audio-centric devices. They are instrumental in testing speakers and headphones, evaluating audio equipment’s frequency characteristics (like amplifiers and equalizers), measuring stage acoustics, and performing various acoustic tests. They help analyze distortion in audio amplifiers, attributing it to factors such as nonlinearities, residual noise, switching distortion, or harmonic components.

Principle of Audio Analyzers

Audio analyzers feature noise filters tailored to the frequency band characteristics of sound, ensuring accurate sound measurement and analysis. They employ oscillators for precise distortion measurement and analysis, alongside calculation functions for signal analysis. Modern analyzers use digital signal processing (DSP) for signal processing, including noise elimination and harmonic analysis. Additionally, some analyzers can perform intermodulation distortion measurements, employing methods like SMPTE and CCIF to analyze distortion generated by harmonic and difference signals.

Other Information on Audio Analyzers

1. Audio Amplifier Distortion Measurement

Building your audio amplifier involves evaluating the distortion factor, where an audio analyzer proves invaluable. It allows for the input of a low-distortion waveform, measuring harmonics and noise components after filtering out the fundamental waveform, aiming for a low distortion rate as a desirable amplifier characteristic.

2. Distortion Factor Measurement Using a PC

With a Windows PC and USB interface, software like WaveGene (signal generator) and WaveSpectra (measurement software) enable the evaluation of distortion rates. These free software tools are recognized among audio professionals for their ability to analyze audio waveform harmonics and visualize the frequency spectrum of music sources.