月: 2022年12月

What Is a Double-Action Hinge?

A double-action hinge is a type of hinge that allows a door to swing in both directions—forward and backward—and return to its original position. These hinges are vital in applications requiring bi-directional opening, such as store doors and traffic partitions.

Typically made from durable materials like steel or stainless steel, double-action hinges come in various colors and finishes to match different door styles.

Uses of Double-Action Hinges

Double-action hinges are commonly used for doors in high-traffic areas, as well as for storage boxes and treasure chests in video games. They are ideal for automatic opening and closing applications and are a popular choice for door remodeling due to their convenience.

When retrofitting these hinges, it’s important to consider the material dimensions, as the hinge’s width and the door’s width determine the operating range of the door’s movement.

Principle of Double-Action Hinges

Double action hinges, as seen in Western movie saloon doors or treasure chests from video games, allow doors to swing in both directions. They can close instantly or slowly, depending on the spring pressure adjustment. This feature provides a versatile opening and closing mechanism suitable for various settings.

These hinges come with either adjustable or pre-set rebound forces and are available in a range of sizes, shapes, and finishes. DIY enthusiasts can find many affordable options on the market, with installation flexibility depending on the width of the door.

What Is a Printed Circuit Board (PCB) Relay?

A PCB relay is a type of relay mounted on printed circuit boards, serving as an electrical component to switch between input and output signals using an ON/OFF control signal.

Originally, relays were mechanical, using a simple structure to control ON/OFF switches. Modern developments include solid-state relays (SSRs) and photorelays, which employ semiconductor and light-emitting/receiving elements.

Applications of PCB Relays

PCB relays are versatile and used for controlling circuits in a range of products. Applications span from small signal level switching to managing large currents in motors and lamps. Common examples include home appliances like washing machines and refrigerators, audio-visual equipment, commercial devices, and automotive control boards.

Principle of PCB Relays

PCB relays can be categorized into mechanical relays, SSRs, and photo relays. Mechanical relays function by controlling a coil to conduct or disconnect contacts. They physically separate the primary and secondary sides, preventing noise leakage but limiting miniaturization due to physical contact.

Semiconductor relays like SSRs and photo relays use a photodiode on the input side and a phototransistor or MOSFET on the output side. The ON/OFF signal is converted to light, then to an electrical signal, maintaining complete electrical separation between the primary and secondary sides. This design offers faster switching speeds and reduces noise interference compared to mechanical relays.

What Is a Knurled Nut?

Knurled nuts, also known as round nuts, grip nuts, quick-tightening nuts, and decorative nuts, feature cylindrical shapes with textured sides to facilitate hand-tightening. The texture, or knurling, is created through rolling or cutting processes, producing fine bumps and dents for improved grip.

Uses of Knurled Nuts

Used similarly to regular nuts, knurled nuts fasten machinery and equipment together with bolts. Their unique feature allows for tool-free tightening, making them ideal for environments where tools are impractical or prohibited, such as clean rooms in pharmaceutical, food, and semiconductor manufacturing.

Principle of Knurled Nuts

Knurled nuts come in flat and twill knurling patterns to ensure a non-slip grip, allowing for sufficient tightening by hand.

Types of Knurled Nuts

Knurled nuts vary by shape, dimensions, screw holes, knurling type, and material. Shapes include standard cylindrical, stepped, and flanged. They can have non-through or through screw holes, and knurling patterns like flat and Ayame (twill) for different grip effects. Common materials include stainless steel, brass, and resin + brass.

How to Select Knurled Nuts

Selection should consider the nut’s size, material, and knurling type. Twill knurling is recommended for stronger tightening. Consider the ease of grip, the required tightening strength, and the installation space when choosing the appropriate knurled nut.

What Is a Local Area Network (LAN) Connector?

A LAN connector is a hardware interface that connects a network cable to devices like PCs, enabling communication within a network. It typically involves a male connector on the cable and a corresponding female connector on the device.

The RJ-45 plug is the most prevalent type of LAN connector, featuring 8 pins for transmitting and receiving data. Designed to prevent incorrect insertion, it includes a securing clip to ensure a stable connection.

Uses of Local Area Network (LAN) Connectors

LAN connectors facilitate the physical link between network devices and the broader network, ensuring a stable and secure communication path. The connectors are integral to setting up wired network connections in various settings, from home networks to large-scale enterprise environments.

Principle of Local Area Network (LAN) Connectors

LAN connectors are designed for differential signal communication, with separate terminals for positive and negative signals. This design supports low signal attenuation and high-speed communication, accommodating different LAN speeds with specific terminal configurations. The form factor for both male and female connectors is standardized globally, following specifications set by regulatory bodies like the FCC.

How to Select a Local Area Network (LAN) Connector

Selection is based on the required LAN speed, distinguishing between connectors suited for Category 5 (100 Mbps) and Category 6 (1 Gbps) communications. While Category 6 connectors can support both standards, using a Category 5 connector in a Category 6 network may lead to communication errors due to inadequate transmission performance.

Other Information on Local Area Network (LAN) Connectors

1. Connector With Built-in Pulse Transformer

To address the challenges of using long cables in LAN communication, some connectors integrate a pulse transformer directly, enhancing circuit compactness and cost-efficiency.

2. Connector With Built-in LED

Integrated LEDs in connectors provide visual communication status indicators, although this design choice may increase the connector’s physical size.

3. Metal Shell

Connectors encased in a metal shell offer improved electromagnetic compatibility (EMC) performance by shielding the connection from external noise. However, this can also result in a larger connector size.

What Is a Printed Circuit Board (PCB) Switch?

A PCB switch, which includes push-button and DIP switches, is designed for mounting on printed circuit boards. These switches are manually operated to turn contacts on and off.

PCB switches come in two primary types: auto-return and holding. Auto-return switches are active only while pressed, reverting to their original state once released. Holding-type switches maintain their state after being actuated until they are manually changed again.

Uses of PCB Switches

The choice between auto-return and holding-type switches depends on the specific application. Auto-return switches require the receiving system to quickly detect changes in state for controlling devices. These are suitable for systems where the switch status is continuously monitored by a controller. Holding-type switches, maintaining a constant state, are preferable when such instant monitoring is not necessary.

Principle of PCB Switches

PCB switches are characterized by a-contact, b-contact, and c-contact types. The a-contact (NO – Normally Open) turns ON when pressed and OFF when released, meaning no current flows through the switch when it is in its default position. The b-contact (NC – Normally Closed) operates oppositely, staying ON until pressed. The c-contact combines features of both a and b contacts, allowing for versatile switching options.

What Is a Step Drill?

A step drill is a tool with multiple blades of varying diameters attached in a step-like fashion to a single drill. This design allows for drilling holes of different diameters and even completing chamfering in one operation.

Typically, drilling holes of various diameters requires using separate drills for each size, risking axis misalignment. A step drill eliminates this need, enabling more precise drilling.

Uses of Step Drills

Step drills are integral in manufacturing for efficient cutting and drilling. Their multi-diameter blades make them ideal for operations requiring simultaneous drilling of different sizes or chamfering. The drill’s material and coating can be chosen based on the work material, enhancing drill longevity and operational productivity.

Principle of Step Drills

Step drills are unique in attaching blades of different diameters to a single drill. While traditional drilling methods involve using drills of increasing diameters sequentially, step drills allow for completing this process with a single tool, significantly improving machining and hole-position accuracy.

Step drills, often resembling a bamboo shoot due to their shape, can drill multiple holes of varying diameters. However, they are not suitable for thick materials due to the shallow depth of each step, in contrast to conventional drills which can handle thicker materials.

What Is a Wire Rope Sling?

A wire rope sling is a lifting tool made from steel wire ropes designed to lift and suspend heavy cargo or objects. Constructed from multiple steel wires with clasps and end fittings, these slings combine strength and flexibility, making them ideal for securely moving heavy loads.

Resistant to high temperatures and corrosion, wire rope slings excel in diverse environments, including maritime settings. Their durability and abrasion resistance ensure long-term usability. Proper handling and training are essential to avoid overloading and potential accidents.

Uses of Wire Rope Slings

Wire rope slings serve multiple purposes across industries:

1. Construction Sites

Essential for lifting building materials and structural components, wire rope slings facilitate the construction and assembly of large structures efficiently.

2. Manufacturing

In manufacturing, these slings are crucial for installing, moving, and maintaining heavy machinery, aiding in production line refurbishments and machinery upgrades.

3. Maritime Operations

On ships, wire rope slings are utilized for anchor operations and cargo handling, streamlining the movement and secure loading of containers at ports.

Principle of Wire Rope Slings

Wire rope slings consist of high-strength steel wire ropes, clasps for load attachment, and end loops for crane hook connections, assembled for maximum lifting efficiency.

1. Wire Rope

The primary component, made of high-strength steel, selected for load requirements and environmental conditions.

2. Clasps

Provide secure attachment points for loads, with common types including eye and sling hooks, chosen based on load shape and size.

3. End Loop

A looped end secures the sling to lifting devices, typically reinforced for added safety and durability.

How to Select a Wire Rope Sling

Selection criteria include sleeve material, rope composition, and working load to match application needs and ensure operational safety.

1. Material of the Sleeve

Chosen to enhance abrasion and corrosion resistance, with aluminum and copper as common options.

2. Rope Material

The steel wire rope’s grade and alloy are selected based on the specific lifting requirements and environmental conditions.

3. Working Load

Crucial for safety, the sling’s design load capacity must not be exceeded, selected according to the weight and type of load.

Other Information on Wire Rope Slings

Types of Terminal Processing Methods

Detailed descriptions of Satsuma processing, lock stopping, and the clip method illustrate the various ways to secure the rope ends, each with its advantages and specific applications.

What Is a Contact Switch?

A contact switch is a switch that controls signals using a contact such as pressure welding or electrical contact.

Contact switches are devices that require many excellent characteristics such as high reliability, long life, and high air resistance due to their important role in controlling signals.

When reliability is required, a contact switch is installed at two or more points, and total control is necessary when all or even one of the switches satisfies the set conditions.

Uses of Contact Switches

Contact switches are used in many fields and locations, regardless of whether they are used for industrial or consumer applications, and regardless of whether they are used outdoors or indoors.

Contact switches are mainly used in production lines for various products, including machining centers. They are also widely used in products that are used by the general public, such as automobiles and motorcycles.

In addition, contact switches are needed and used in elevators, escalators, and many other places where electrical control is required.

Features of Contact Switches

The key point of contact switches is the contact mechanism.

The mechanism of contact switches needs to be changed depending on whether the object is hit and then moves, or whether it stops there.

For example, if the target object moves as it is, the contact switches only need to detect a change in stroke, but if it stops, it is necessary to consider using a pressure sensor.

If the object is conductive, the contact switches should be designed to short-circuit at the tip of the switch, which would be easy to implement.

In addition, if the condition that light is blocked by contact is conceivable, it will be possible to utilize an optical sensor.

Today, sensor technology is rapidly evolving, and the groundwork has been laid for using various types of sensors.

What Is an Audio Amplifier?

An audio amplifier is a device that amplifies music signals for music playback through speakers or headphones.

Music signals may be output from media, such as records or CDs, through a playback device called a player, or they may be transmitted via FM radio broadcasts or the Internet. The primary role of an audio amplifier is to amplify these music signals to provide enough power to drive speakers and headphones.

Uses of Audio Amplifiers

Audio amplifiers are used to play music through speakers. On the other hand, devices that handle music signals include record players, CD players, FM tuners, network players, etc. The maximum output voltage of a CD player is about 2 V, while the signal from a record player is a weak analog signal of about 1 mV. A network player may have a digital signal output.

Audio amplifiers select the desired one from these input signals and output music signals that drive speakers and headphones through frequency response correction and volume level adjustment mechanisms. When watching TV or movie software, audio signals may also be input to an Audio Amplifier to drive external speakers for a more realistic sound.

Audio amplifiers used for this purpose are also called AV Amplifiers and are characterized by their multi-channel output (5.1 channels or more).

Principle of Audio Amplifier

An audio amplifier consists of a preamplifier section that processes the incoming music signal and a power amplifier section that amplifies the power of the music signal.

1. Preamplifier

The preamplifier consists of processing circuits according to the signal source, an input signal selection switch, a tone control circuit to strengthen or weaken the bass and treble frequencies, and a volume control to adjust the volume. The above processing circuits include the following, which can handle a variety of signal sources.

• Phono Equalizer Amplifier
  Corresponding to record playback
• Buffer Amplifier
  Receives signals from CD players, etc. in a high-impedance state and transmits music signals in a low-impedance state to the circuit in the next stage
• D/A Converter
  Converts digital input signals from the USB port to analog music signals

2. Power Amplifier

This circuit is used to amplify the output signal from the preamplifier to drive speakers. The output power required ranges from several tens of watts to over a hundred watts. Since the speaker impedance is as small as 4 to 8 ohms, the output impedance of the power amplifier must be as low as possible.

Types of Audio Amplifiers

Audio amplifiers can be classified into the following forms based on the purpose of music reproduction and required performance.

1. Pre-Main Amplifier

This is a common type of audio amplifier that combines a preamplifier and a power amplifier in a single housing. Since it does not have a built-in signal source, it is used by connecting a CD player, FM tuner, or other device to the input terminals. Multiple sound sources can be connected, so the desired one can be selected with the selection switch to sound the speakers.

2. Separate Amplifier

The preamplifier and power amplifier are housed in separate enclosures, and this type of product is required when extremely high-quality music reproduction is desired. The power amplifier drives a large amount of power, but it has the advantage that the noise generated by the power amplifier does not affect the preamplifier.

However, the products available are expensive and therefore not common.

3. Receiver

A preamplifier with a built-in FM tuner is sometimes called a receiver. Once used in relatively inexpensive stereo systems, this form of product has become less common in recent years.

4. Headphone Amplifier

This audio amplifier is designed specifically for listening to music through headphones, without using speakers. Since the power required to drive headphones is about 100mW and a large power amplifier is not necessary, small products are being sold.

Audio amplifiers in this form have increased dramatically since music distribution over the Internet became widespread. Another feature is that many models have a built-in D/A converter so that they can receive digital music signals as they are.

5. AV Amplifier

As mentioned above, this amplifier is used for viewing TV programs and movie software. It incorporates a number of power amplifiers to take advantage of special sound effects by arranging multi-channel speakers.

What Is a Cap Nut?

Cap nuts, also known as domed cap nuts or acorn nuts, are hexagonal nuts with a closed end, lacking a through hole. Their design conceals the end of threaded rods or bolts, providing a clean and safe finish.

The term “cap nut” reflects their domed shape, resembling a cap. Synonyms include “cosmetic nut,” “acorn nut,” and “dome nut.” They are also referred to as “bag nuts” and “hexagon socket nuts,” defined as follows:

• Bag Nut: A nut with a closed end to conceal the tip of the threaded rod or bolt.
• Hexagon Socket Nut: A nut with a hexagonal shape for secure tightening and loosening.

Uses of Cap Nuts

Figure 1. Example of Cap Nut Use

Cap nuts enhance the appearance of assemblies by covering the exposed ends of bolts, reducing the risk of injury from sharp edges. They are particularly valued in applications requiring safety and tamper resistance, such as playground and gym equipment, as well as aircraft seating.

While cap nuts can be coated for corrosion resistance, their threads may remain vulnerable. Their design helps prevent the ingress of contaminants into bolt threads, simplifying maintenance.

Principle of Cap Nuts

Figure 2. Cap Nut and Bolt Length

When using cap nuts, the length of the bolt is critical to ensure the nut can be properly tightened without the bolt protruding. The hexagonal dimensions of cap nuts are standardized, allowing for use with standard hex nuts in double-nut configurations to prevent loosening.

Types of Cap Nuts

1. Standard Type

Figure 3. Types of Cap Nuts JIS Standard

Cap nuts are categorized into three types, each available in a smaller hexagonal version for various applications.

• Type 1: Integrated hexagonal and cap parts without a thread relief groove.
• Type 2: Integrated hexagonal and cap parts with a thread relief groove.
• Type 3: Hexagonal part and cap welded together.

Types 1 and 2 are machined from solid bars, whereas Type 3 involves welding a dome to a hex nut.

2. Non-Standard Types

Figure 4. Types of Cap Nuts Other Than JIS Standard

Additionally, cap nuts come in various designs and features, including those with mechanisms to prevent loosening, such as dome/flange types and cap U nut types.

3. Materials

Cap nuts are manufactured from steel, stainless steel, or copper alloys, each offering specific properties suitable for different applications and environments.

4. Surface Treatment

Surface treatments, such as trivalent chromium plating, are applied to steel cap nuts to enhance corrosion resistance.

5. Threads

The threads of cap nuts conform to metric standards for compatibility with various bolt sizes, ensuring a secure fit.