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What Is a Cable Tie?

A cable tie, also known as a bundling band, is a band made of plastic used to bundle and organize multiple cables, tubes, etc. Once applied, they are designed to be secure and non-removable, although some types can be re-bundled.

Cable ties are known by several names including bundling ties, cable ties, and wiring bands. Other terms like interlock and interlock tie are registered trademarks of Helaman Tighten, and thus, are specific to that brand.

Uses of a Cable Tie

Cable ties are primarily used for bundling items such as wiring and tubing to improve manageability. They can be used to group multiple wires or pipes, or attached to a fixture to prevent movement of the cables or pipes.

Usage involves wrapping the tie around the object and threading the tail through the head. Once it clicks into place, the serration or jagged edge catches on the claw in the head, securing the tie. Due to their strength, cable ties require cutting tools like nippers for removal.

How to Choose a Cable Tie

The key factor in selecting a cable tie is its size. A small tie may not be sufficient for larger bundles, and a large tie could be cumbersome for smaller items. It’s important to match the size of the tie to the items being bundled.

Material is another important consideration. Different materials offer varying levels of strength, heat resistance, and chemical resistance. Choose the material based on the intended use, location, and environmental conditions. Colored ties are also available for identification purposes, helping to easily locate connection points of wires or hoses.

Recently, Velcro tape types have become popular for their ease of use and adjustability. While not suitable for heavy loads or vibrations, Velcro ties are ideal for light-load binding due to their reusability and ease of adjustment.

What Is a CPU Cooler?

A CPU cooler is a component used to cool the CPU of a computer, such as a PC, etc. Since the CPU generates heat during operation, problems such as thermal runaway, in which the semiconductors inside the CPU do not operate properly, can occur if the CPU is not cooled appropriately. For this reason, CPU coolers are installed according to the power consumption of the CPU.

There are two main types of CPU coolers: air-cooled and water-cooled. Most of the CPU coolers in PCs on the market are air-cooled, while water-cooled coolers are often used in home-built PCs.

Usage of CPU Coolers

CPU coolers are used by attaching them to the CPU. It is installed in most models of desktop and notebook PCs on the market. The sound of the wind when the computer is in use is due to the electric fan operating to release the heat generated by the CPU into the atmosphere.

Other than commercial PCs, CPU coolers are sold separately to build your own PC.

Principle of CPU Cooler

The components of an air-cooled CPU cooler are a base plate, a heat pipe, a heat sink, and an electric fan. The heat path from the CPU to the air is in the order of CPU → base plate → heat pipe → heat sink → air. Heat pipes and electric fans are sometimes omitted.

The materials and structure of CPU coolers are designed to dissipate heat efficiently. Copper and aluminum alloys are used as materials for the components in consideration of thermal conductivity and heat transfer coefficient to the air. In order to efficiently transfer heat from the CPU to the base plate, thermal conduction grease is applied to the contact surfaces.

To dissipate heat from the heat sink to the air, many CPU coolers use an electric fan to generate a forced airflow. The electric fan’s airflow is used to cool the heatsink and other elements on the motherboard (board), such as memory. The airflow inside the case is also designed with airflow considerations in mind, as the air that the heat sinks have heated must be discharged smoothly to the outside of the computer case.

The size of the heat sink is essential to increase the heat dissipation capacity of the air-cooled system. A large heat sink is required to cool a CPU with high power consumption, but the installation space in the case limits the size of the heat sink.

The components of a water-cooled CPU cooler can be thought of as replacing the heat pipes that play the role of heat conduction in air-cooled systems with cooling water hoses and the heat sinks for dissipating heat with radiators. Since radiators can be installed outside the case, they can be easily increased in size, and cooling capacity can be easily improved. However, there is a risk of failure due to cooling water leakage.

What Are Hard Disk Drives?

Hard Disk Drives (HDDs) are typical external storage devices. It is a non-volatile storage device that retains data even when the power is turned off.

The structure consists of multiple metal disks with magnetic materials stacked on top of each other. Data is read and written by rotating the disks at high speed and magnetizing the magnetic material by bringing a magnetic head close to it.

Since the magnetic head and disk are brought into close proximity when reading and writing data, the structure is vulnerable to vibration. Because of the large amount of data handled, high-speed

communication is required for the connection, and standards such as SCSI, IDE, and SATA are used. In the past, cables using SCSI and SATA standards were often used to connect external HDDs.

However, in recent years, as data transfer speeds have increased through USB connections, USB is increasingly being used to connect external HDDs.

Usage of Hard Disk Drives

Hard Disk Drives are often used as mass storage devices to store data on PCs. In addition to PCs, hard disks are also widely used in electronic devices such as external storage devices, servers, network drives, hard disk recorders in home appliances, and game consoles.

In recent years, as the capacity of SSDs have increased, they are increasingly taking on the role traditionally played by hard disk drives: HDDs use magnetic disks, while SSDs record data in NAND flash memory, which uses semiconductor elements.

The advantage of hard disk drives over SSDs is that large capacities can be procured at low cost. For this reason, SSDs are increasingly being used as storage devices for frequent read/write operations, while hard disk drives are being used as secondary data storage devices.

Principle of Hard Disk Drives

A hard disk generally consists of a disk, motor, magnetic head, and control circuit.

In a hard disk, a single disk is called a platter. The surface of the platter is coated with magnetic material, which is used to magnetically record data. In order to obtain the data capacity, multiple platters are generally stacked on top of each other.

Hard disks are equipped with motors to operate them. There are two types of motors: one is the motor that spins the platters. This is called a spindle motor. The faster this motor can rotate, the faster data can be read and written, so the number of revolutions is sometimes used as a performance indicator.

The other motor drives the arm that moves the magnetic head. The magnetic head is what reads and writes the data on the platters in a hard disk. Since there are multiple platters, magnetic heads are mounted according to the number of platters. The principle of writing data is to apply a magnetic force to the magnetic material on the platter surface using an electric current.

Which direction the magnetic force (the direction of the S and N poles of the magnet) is facing corresponds to the 0 and 1 information in the digital record. When reading, data is read based on the resistance value that changes under the influence of the magnetic field on the platters.

How to Select Hard Disk Drive

There are different points of focus for selecting an internal hard disk drive and an external HDD.

1. Internal Hard Disk Drive

You may purchase an internal hard disk drive to build your own computer or to improve the performance of your desktop computer.

First, check the connection standard (IDE or SATA) of the environment in which you intend to build or replace the HDD, and choose one that fits.

Next, choose a disk size between 3.5″ and 2.5″. 3.5″ is generally for standard desktop PCs, while 2.5″ is for notebook PCs or space-saving desktop PCs. A 2.5″ disk can also be installed by installing a mounter in the 3.5″ space of a desktop PC.

Select the capacity that best suits the intended use. Unnecessarily large capacities will increase the cost.

The most common disk rotation speeds are 7,200 rpm and 5,400 rpm. The higher the speed, the faster data can be read and written, but it is also more expensive and generates more heat. It is advisable to select a disk drive based on the application and whether or not high speed read/write speed is required.

2. External Hard Disk Drive

There are two types of external hard disk drives: stationary and portable. The stationary type is heavy and not suitable for carrying around, but inexpensive, while the portable type is lightweight and is designed to protect against shocks while being carried around.

The interface to be connected to an external hard disk drive is selected based on the device to be connected. Connection standards include USB, Thunderbolt, and eSATA, etc. Since the transmission speed of USB, etc. varies greatly from generation to generation, it is advisable to confirm the use in detail and select one that supports the expected transmission speed.

What Is a PCI Board?

A PCI board, also called an expansion board, is a board that can be connected to a PC to expand the available functions.

They are mainly used in desktop PCs and can be connected to motherboards or other expansion board interfaces. Some PCs may not have an interface for PCI boards.

There are many types of PCI boards on the market, and the functions that can be added vary from board to board.

Uses of PCI Boards

There are many different types of PCI boards, but the most common types are as follows.

• • Graphic cards: Allow expansion of connectors for connecting a PC to a monitor.
• Network boards: Allow expansion of connectors for LAN, fiber optics, etc., to the PC.
• Soundboards: Extend the audio interface to your PC.
• Storage boards: Allow expansion to control storage on a PC.
• For external interface: You can add an external interface such as a USB.
• Tuner: You can extend a PC with a digital terrestrial tuner, etc.

Principles of PCI Boards

PCI boards come in various standards, and care must be taken to select the right PCI board for your PC, or you will not be able to connect correctly.

The most common standards are PCI and PCI Express. Recently, PCI has been less commonly used, and PCI Express is the mainstream.

Within PCI Express, the standard is subdivided according to the number of lanes, and the number of connector pins and connector cutout positions at the connection varies. The higher the number of routes, the faster the communication speed.

PCI also comes in two sizes: regular PCI and LowProfile PCI. LowProfilePCI is often used for space-saving PCs and cannot be installed with standard PCI. Standard PCI and LowProfilePCI have different board sizes and bracket sizes.

Also, some types of PCI boards use two or more brackets, and if there is not enough space for the brackets, the board may not be able to be installed.

What Is an X-Ray Tube?

An X-ray tube is a type of X-ray generation tube that converts electrical input power to produce X-rays.

X-Ray Tubes are classified into two types according to the type of tube: sealed tubes, in which the inside of the tube is always kept in a vacuum, and open tubes, in which a vacuum pump is installed on the outside of the tube to create a high vacuum.

Sealed tubes are also known as anode tubes. They are further classified into two types: rotating anode tubes with a rotating anode and fixed anode tubes without a rotating anode. The fixed-anode tube has a rotating anode, which allows heat dispersion and increases the current flowing through the X-ray tube.

X-Ray Tubes are classified into microfocus and mini-focus (or millifocus) types, depending on the focal spot size. These X-ray tubes have a focal spot size on the order of microns and millimeters, respectively.

Uses of X-Ray Tubes

X-Ray Tubes are used as X-ray generators in various fields. X-rays are electromagnetic waves with a wavelength shorter than that of ultraviolet rays, and their high energy allows them to penetrate through materials.

The following are some of the applications that take advantage of this penetrating effect:

• Medical field
  General radiography, mammography, CT examinations, X-ray therapy used in cancer treatment, etc.
• Scientific and industrial fields
  X-ray diffraction, X-ray fluorescence analysis, nondestructive testing, thickness and other material testing, airport baggage inspection, etc.

Principle of X-Ray Tubes

An X-ray tube consists of an enclosure, a cathode, and an anode . When a high voltage is applied between the cathode and anode after the cathode filament is heated by an electric current, hot electrons are emitted from the filament and are directed to the anode target at high speed.

1. X-Ray Driven

The thermal electrons are attracted to the nucleus of the anode material, such as tungsten, and rapidly change direction, releasing energy. At this time, 99% of the energy is converted to thermal energy, but the remaining 1% is emitted as X-rays. These X-rays are called bremsstrahlung X-rays and are characterized by their continuous spectrum.

Where the thermal electrons pass in relation to the nucleus is not uniquely determined, and the X-ray intensity varies depending on where they pass. Therefore, bremsstrahlung has a continuous spectrum.

2. Characteristic X-Rays

Some thermal electrons rarely collide with electrons of the target atom. The collided electrons gain energy from the thermal electrons and are repelled, and then transition to the outer electron orbitals, but because they are unstable, they quickly return to their original orbitals.

The difference in the energy state of the electron orbital is emitted as X-rays. X-ray tubes produce mostly bremsstrahlung X-rays, which are extracted through a window made of beryllium or other material with low X-ray absorption in the tube’s enclosure.

Other Information on X-Ray Tubes

1. Tube Voltage and Tube Current

The intensity and energy of the X-ray tube depend on the tube voltage and current.

Tube voltage
The tube voltage is the voltage applied between the anode and cathode of the X-ray tube. The higher the tube voltage, the shorter wavelength X-ray tube produces. The tube voltage is a parameter that affects the intensity and energy.

Tube Current
The current that flows through the inside of the X-ray tube. The current is generated when thermal electrons generated at the cathode collide with the anode. In a rotating anode tube, the anode rotates to disperse the heat and increase the tube current.

There is a proportional relationship between the tube current and the total X-ray tube intensity. On the other hand, the X-ray energy does not change when the tube current is changed.

2.Transmission Properties of X-Rays

Since X-rays are electromagnetic waves with a very short wavelength, they have the property of transmitting through materials. The transmission rate varies depending on the material, and X-rays are attenuated during transmission.

The higher the energy of the X-ray, the greater its transmission ability.

What Is an Isolator?

Isolators are devices designed to separate or insulate components or systems. They play critical roles across various industries, including electrical and electronics, construction, and pharmaceuticals, by isolating analog signals, insulating buildings from earthquakes, and protecting against external contaminants.

Uses of Isolators

The application of isolators varies significantly by industry:

1. Electronics Industry

Used for surge voltage protection and signal separation, isolators in electronics ensure the integrity of signal-receiving equipment.

2. Construction Industry

In construction, isolators serve as earthquake-resistant supports under buildings, utilizing high-elasticity materials like rubber to dissipate vibrations.

3. Pharmaceutical Industry

Pharmaceutical isolators provide sterile environments for drug development and patient care, employing negative pressure systems and gas sterilization to prevent contamination.

Principle of Isolators

The operational mechanisms of isolators vary across different fields:

1. Electronics Industry

Electrical signal isolation involves amplifying and converting input signals for output, serving also as signal converters.

2. Construction Industry

Vibration-dissipating structures in construction use materials like seismic isolation rubber to reduce building movement during earthquakes.

3. Pharmaceutical Industry

Isolators in pharmaceuticals maintain sterile conditions through negative pressure and gas sterilization, similar to draft chambers.

Types of Isolators

Isolators are categorized into optical and digital types:

1. Optical Isolators

Using LEDs and light-receiving elements, optical isolators transmit signals via light, offering simple, reliable, and cost-effective solutions.

2. Digital Isolator

Digital isolators isolate using capacitors or coils to transmit digital signals, known for their long life and high performance but limited to digital applications.

How to Select Isolators

Selection depends on application requirements:

1. Optical Isolator

Chosen for their distance transmission capability, optical isolators suffer from efficiency drops at temperature variations.

2. Digital Isolator

Preferred for applications requiring high performance and longevity, digital isolators are evolving, with costs and variety being considerations. They are used in applications that are difficult to handle with photocouplers.

What Is an Enabling Switch?

Enabling switches, also known as enabling grip switches, 3-position enabling switches, or simply enable switches, are safety devices integrated into teaching pendants for industrial robots and other machinery.

These switches allow operations only when the operator demonstrates clear intent by holding the switch in the ON position, ensuring that industrial robots are manually operated under controlled and intentional circumstances. This feature is crucial for preventing accidental robot operations and ensuring worker safety.

Uses of Enabling Switches

Enabling switches are critical safety components mounted on teaching pendants, which are used to manually operate equipment like industrial robots. While safety measures usually prevent worker access to operational areas of production equipment, there are instances where operators need to bypass these measures, such as during startup or troubleshooting. Enabling switches ensures that machinery operates only when the operator intentionally engages the switch, thereby protecting them from unintended and potentially hazardous actions.

Structure of Enabling Switches

Unlike standard two-position “ON/OFF” switches, enabling switches operate on a three-position “OFF/ON/OFF” system, which is button-operated. The first position is a neutral state where no contact is made, and the machinery remains inactive regardless of any attempted operations. A light press transitions the switch to the second position, enabling operation as commands are executed. Releasing the button reverts it to the neutral state, allowing for immediate cessation of activity. A stronger press from the second position shifts it to the third, where the machinery stops upon receiving a stop command.

Principle of Enabling Switches

The design of enabling switches considers human reflexes in dangerous situations—whether releasing or gripping the object more tightly. This ensures immediate machine stoppage in both scenarios, thus protecting the operator during unexpected robot movements. The dual-stop mechanism accommodates the unpredictable nature of human reflexes, safeguarding the operator by halting operations whether the switch is released or pressed firmly.

How to Select Enabling Switches

When selecting enabling switches and systems, prioritize those with high safety standards suitable for hazardous areas. Opt for switches with dual contacts and systems designed with controllers capable of shutting down machinery and maintaining safety even if one contact fails. Such systems are engineered to detect faults only when the two contact signals are in agreement, enhancing operational safety.

What Is an Image Intensifier?

An image intensifier is a device that detects extremely weak light or X-rays and amplifies them thousands to tens of thousands of times to make them visible.

Image intensifiers intensify and express light rays. Among these devices are, “X-ray image intensifiers” which visualize X-rays, and “MCP image intensifiers” which visualize weak light such as fluorescence, etc.

Since fluorescence and nighttime light are extremely weak, they are converted to electrons and then electrically amplified to create a contrast that make them appear like an image.

Uses of Image Intensifiers

When you hear the word “X-ray,” you probably think of medical X-rays. Of course they are also used in this case. However, image intensifiers are often used because they can visualize X-rays in the form of an image by simply exposing the patient to very weak X-rays, and they can also view X-rays in real-time.

MCP image intensifiers are also used in fluorescence imaging equipment for fluorescent staining of cells.

Principle of Image Intensifiers

An image intensifier is a device, but what is its inner structure?

An image intensifier consists of three components: a photocathode, which receives light; a device, which amplifies electrons; and a fluorescent surface, which reflects the amplified electrons.

We will now explain the principle using an MCP image intensifier as an example.

Normally, when an MCP image intensifier detects light reflected on the photocathode, the light is converted into electrons. The electrons are then amplified in a microchannel plate, and the image produced when they hit the phosphor that serves as the screen is output as an image.

In the case of X-ray image intensifiers, the conversion from X-rays to electrons occurs at a photocathode. The electrons are further accelerated and focused by the focus electrode and anode power supply to obtain an image.

In this way, the conversion to electrons is performed by a device that matches the fluorescence and X-rays, and the human eye sees the amplified image as a visible image.

What Is a Gunn Diode?

A Gunn diode is a type of diode used in microwave band oscillators and other devices.

Gunn diodes are diodes that utilize the Gunn effect. N-type gallium arsenide (GaAs) is mainly used, and physicist J.B. Gunn discovered that when a DC electric field is applied to a GaAs crystal and exceeds a certain threshold value, oscillation occurs in the microwave region. For this reason, this phenomenon is called the Gunn effect.

Gunn diodes have a region of negative resistance, and this effect is used in microwave oscillators. Negative resistance here refers to the electrical characteristic that current decreases as voltage increases.

Uses of Gunn Diodes

Gunn diodes are commonly used in the microwave region for oscillator radar applications using the Gunn effect.

When a Gunn diode is mounted in a cavity or waveguide and a DC voltage is applied, it oscillates with an intrinsic vibration that depends on the thickness of the crystal. Although the structure is relatively simple, the frequency stability is not as good as that of the usual microwave control method using a VCO or PLL, so it is often used for speed sensors using the Doppler effect in addition to communications.

Familiar applications include speed guns for baseball and radar for speed enforcement.

Principle of Gunn Diodes

Gunn diodes take advantage of the microwave band oscillation phenomenon that occurs when electrons rapidly transition to the band with the higher energy level when a voltage exceeding the critical electric field is applied to a semiconductor crystal with two energy bands. When a graph of energy is drawn, it has two conduction bands with different bottom energies and wave numbers.

When voltage is applied, an electric current flows, and the electrons responsible for this current are those in the conduction band. Normally, more electrons exist in the conduction band with lower energy at the bottom, and as the voltage increases, more electrons are in the conduction band with higher energy. When a certain voltage is exceeded, electrons from the lower level conduction band move to the higher level conduction band, resulting in a decrease in mobility.

This phenomenon causes a decrease in the apparent mobility of electrons, or current, when the voltage is increased above a certain voltage, and thus has the characteristic of negative resistance. As the voltage is further increased, the electrons in the lower level conduction band are transferred to the higher level conduction band, and the current increases again.

At this point, an avalanche of rapid, high-speed electron transfer occurs in the microwave band, resulting in the oscillation phenomenon. While general VCOs (voltage-controlled oscillators) utilize a negative resistance that takes advantage of the impedance matching of transistors, Gunn diodes make good use of the inherent energy bands of semiconductor crystals.

Other Information on Gunn Diodes

1. Application to Speed Sensors

Velocity sensors, a typical application of Gunn diodes, generally use a physical phenomenon called the Doppler effect. The Doppler effect is the principle that the reflected wave of an electromagnetic wave irradiated onto an object moving at high speed is observed at a different apparent frequency than the original frequency of the irradiation.

The frequency of a Gunn diode in a GaAs crystal is about 10 GHz, and the speed of the irradiated object is calculated from the difference in frequency variation. Incidentally, this difference in frequency variation is described as a “whirr” in physical terms, and the variation relative to a frequency of 10 GHz is a very small percentage for speed measurements in the 100 km range for baseball speed guns and automobile speed measurements. 

2. Expansion to Sub-Terahertz Frequencies

Gunn diodes and similar diodes, as well as resonant tunneling diodes, are currently the focus of attention in research institutions as research materials for sub-terahertz frequency oscillators. 

What Is a Scintillator?

A scintillator is a general term for materials that emit light when exposed to charged particles or radiation.

They are classified into inorganic and organic scintillators. Inorganic scintillators, suitable for detecting gamma rays and X-rays, are made from crystals with high atomic numbers. They emit a large amount of light and have excellent energy resolution but respond slowly. Organic scintillators, including plastic and liquid types, are inexpensive, lightweight, and respond quickly, making them ideal for detecting alpha and beta rays.

Scintillators are used in various fields as part of scintillation detectors.

Uses of Scintillators

Scintillators convert radiation into light, ranging from ultraviolet to visible. This light is then transformed into electrical signals by photomultiplier tubes or opto-semiconductors, which are processed to generate images and other radiation-related information.

Applications include X-ray computed tomography (X-ray CT), positron emission tomography (PET), airport baggage screening, food inspection, non-destructive testing of electronic components, exploration of oil and mineral resources, nuclear reactor radiation monitoring, and research in particle, nuclear, and space physics.

Principle of Scintillators

The emission principle of scintillators varies between inorganic and organic types.

1. Inorganic Scintillators

In inorganic scintillators, charged particles or radiation excite electrons from the valence to the conduction band. The recombination of these electrons with holes in the valence band produces scintillation light, corresponding to the energy difference. Impurities in the crystal lattice create new energy levels, allowing the emission of visible light from these modified structures.

2. Organic Scintillators

Organic scintillators emit light through the excitation of individual molecules. Radiation excites electrons to higher energy states, predominantly to the first excited state, resulting in fluorescence. Some electrons may also transition to higher excited states before returning to the first excited state and eventually to the ground state, emitting phosphorescence or delayed fluorescence.

Structure of Scintillators

The structure of scintillators differs between inorganic and organic types.

1. Inorganic Scintillators

Examples include NaI:Tl, LSO:Ce, lead tungstate (PbWO₄), gadolinium silicate (GSO: Gd₂SiO₅ with Ce), and bismuth germanate (BGO: Bi₄Ge₃O₁₂). NaI:Tl, a commonly used scintillator, must be sealed to prevent degradation from moisture absorption.

LSO:Ce, an oxide-based scintillator, emits light via transitions in Ce³⁺ and offers faster response times compared to NaI:Tl.

2. Organic Scintillators

Organic scintillators include crystal, liquid, and plastic types. Liquid scintillators, such as naphthalene, are durable against strong irradiation. Organic molecules like anthracene and stilbene, with their pi-electronic structures, offer multiple excited states but are less commonly used due to their anisotropic response and processing challenges. Plastic scintillators, created by dissolving organic emitters in plastic, are user-friendly and suitable for detecting alpha and beta rays, though less effective for gamma rays.