月: 2023年3月

What Is a Bulk Converter?

A bulk converter is a type of power supply circuit designed to step down a general-purpose DC voltage input to a lower DC voltage output.

It ensures the generation and delivery of a stable DC voltage, even when the input voltage fluctuates slightly. Bulk converters are used to generate specific voltages from a general voltage source, supplying the required voltage to electronic device circuits.

Uses of Bulk Converters

Bulk converters are essential for adjusting the output voltage supplied to electrical circuits. For example, while household power outlets typically deliver 100 V AC, many electronic device circuits operate on DC power. Therefore, AC power needs conversion to DC. Further, if electronic devices incorporate microcontrollers or logic ICs, the DC voltage converted from AC must be stepped down to levels like 5 VDC or 3.3 VDC, necessitating the use of bulk converters.

Principle of Bulk Converters

Bulk converters can be categorized into series regulators and switching regulators.

1. Series Regulator

A series regulator consists of a control element (often a bipolar transistor), a control circuit, and a reference voltage source. It is connected in series between the power input and output, reducing the output voltage below the input voltage. The control circuit modulates the transistor’s operation to maintain a constant output voltage despite input or output fluctuations. However, it has higher power consumption and generates more heat.

2. Switching Regulator

Switching regulators comprise a switching element (usually FETs), a control circuit, and a voltage smoothing circuit (inductors and capacitors). The control circuit modulates the FETs’ ON/OFF states to achieve the target output voltage, while the inductor and capacitor smooth the output into stable DC voltage. This type is more efficient than series regulators, allowing for higher output currents, but it tends to produce more noise.

How to Select a Bulk Converter

1. Output Current

For applications requiring higher output currents, a switching regulator is preferable due to its lower heat generation and efficiency. Series regulators, although generating more heat, are simpler and more suitable for lower current applications.

2. Cost

Switching regulators, due to their complexity and additional component requirements, are generally more expensive than series regulators. If cost is a concern, a series regulator is a more economical choice.

What Is a Microcomputer Evaluation Board?

A microcomputer evaluation board is a tool used for developing software for single-chip microcomputers, typically provided by the microcomputer’s manufacturer.

These boards are essential in the early stages of software development, especially when the final device is not yet available. They allow developers to test and debug software without having to design a complete circuit, including peripheral circuits. This approach saves time by isolating software issues from potential hardware defects.

As these boards are guaranteed to function correctly by the manufacturer, developers can focus on software debugging more efficiently.

Uses of Microcomputer Evaluation Boards

Microcomputer evaluation boards are used for developing and testing software in various contexts, particularly when the final hardware design is still in progress. They serve as virtual target devices, enabling software development in the absence of the actual hardware.

Principle of Microcomputer Evaluation Boards

These boards contain essential hardware components required for a microcomputer, such as a reset circuit, an oscillator, display units (like 7-segment LEDs or LCDs), input switches, and serial communication interfaces. They are compatible with various emulators for enhanced debugging and testing.

1. ICE (In-Circuit Emulator)

An ICE emulates a microcomputer’s CPU, allowing program verification directly on the development board. It’s equipped with emulation chips and memory, handling peripheral circuit operations on the target board.

2. On-Chip Emulator

Some flash memory-based microcontrollers have built-in debugging modules. Commands from a development environment are converted by a debugging cable or a converter on the target board, facilitating communication with the microcontroller’s CPU.

3. JTAG Emulator

JTAG emulators, complying with the JTAG standard for testing integrated circuits and boards, are a type of on-chip emulator that aids in debugging and testing, even on difficult-to-probe boards like those with BGA packages.

In cases where the hardware required for control software development isn’t available on the evaluation board, additional hardware boards can be connected to augment its capabilities.

Other Information on Microcomputer Evaluation Boards

1. How to Use a Microcomputer Evaluation Board

These boards can execute software, output electrical signals, and in some cases, facilitate network communication testing. They usually support programming in languages like C.

2. Microcomputer Evaluation Board FPGA

FPGAs (Field Programmable Gate Arrays) are devices for creating rewritable logic circuits. They allow on-the-spot corrections using hardware language to describe semiconductor circuits. These circuits include basic logic gates like AND, OR, NOT, and combinations like NAND, NOR, and EXOR, which can be operated by rewriting in hardware language.

2. Difference From Microcontroller Development Boards

Microcontroller development boards cater to embedded and IoT device development, supporting a range of 8-bit to 64-bit microcontrollers. Some can run real-time OS or Linux for IoT applications, focusing on controlling sensors and drive systems. They are versatile tools for program testing and circuit testing in early development stages.

What Is a Rectangle Connector?

A rectangle connector is a square-shaped connector that can be used for a wide range of applications.

Examples of rectangle connectors include D-SUB terminals for transmitting video signals, DVI terminals, HDMI terminals, and DisplayPort terminals. These connectors vary in shape and size.

USB terminals, which are used to connect PCs, smartphones, and other devices for signal transmission and peripheral device connection, often employ rectangle connectors. These come in various shapes and sizes.

The RJ-45 connector, used for Ethernet signal transmission, also falls under the rectangle connector category, despite its slightly unique shape.

Uses of Rectangle Connectors

Rectangle connectors, such as D-SUB connectors, were once the mainstay for transmitting video signals. However, with digitalization, they are now being replaced by HDMI and DisplayPort connectors, via DVI terminals.

The DVI terminal, a successor to the VGA standard, supported analog RGB and was the sole digital standard before the introduction of HDMI. However, current manufacturers are not developing devices with this standard.

DisplayPort is a digital interface standard developed as a replacement for DVI.

USB connectors, another type of rectangle connectors, are widely used for connecting PCs and smartphones to various devices such as drive units, USB memory devices, printers, and other peripherals.

Principles of Rectangle Connectors

Representative products of rectangle connectors include HDMI and USB connectors.

HDMI connectors transmit digital video and control signals. They are used for connections such as between a TV and a DVD/BD/HDD recorder or an AV amplifier.

For example, when connecting a TV to a recorder, the recorder’s video signal is used for playback on the TV. HDMI also transmits control signals, known as HDMI-CEC (Consumer Electronics Control). This feature allows a TV’s remote control to simultaneously operate a connected recorder.

With HDMI-CEC, turning on the TV with its remote control can also power on the recorder, and vice versa. It is also possible to use the TV remote to select and play content from the recorder.

The HDMI standard, including the HDMI-CEC subset, has been standardized by manufacturers’ organizations. Therefore, basic commands are consistent across different brands.

USB connectors, on the other hand, are primarily used for transmitting digital data, whereas HDMI focuses mainly on video signals. USB standards, like HDMI, are standardized by industry groups.

USB 1.0, first standardized in 1996, has evolved over time, culminating in the release of USB4 in September 2019. The maximum transmission speed of USB 1.0 was 12 Mbps in half-duplex mode, but USB4.0 offers speeds up to 40 Gbps in full-duplex mode.

What Is a Locating Ring?

A locating ring is a vital component used to align the molding machine with the mold. Typically, two or four rings are attached to the mold to ensure precise alignment between the nozzle of the molding machine and the mold’s sprue. Proper alignment is crucial to prevent leakage of injection material and defects in the molded product, which can occur due to misalignment between the mold’s sprue bushing and the injection nozzle of the molding machine.

Uses of Locating Rings

Locating rings are mounted on the top of the mold to align the injection nozzle of the injection molding machine with the entrance of the sprue bush and the hole in the fixed side mounting plate of the mold. Their use not only ensures high-precision positioning between the injection molding machine and mold but also facilitates the mounting of the mold to the machine.

Types of Locating Rings

There are four main types of locating rings: Type A, Type B, Type AJ, and Type BJ. The AJ and BJ types differ based on the inner shape of the rings, with the AJ type having no taper and the BJ type having a taper. This differentiation likely originated from the need to facilitate mold fitting when locating rings were first used in aligning injection molding machines with molds. In the field of machining, tapered connections have long been used to ease machine fitting. The revised Type A is now defined as a tapered type, while Type B is defined as a type without an internal hole.

What Is an Expansion Board?

An expansion board is a hardware component used to enhance the functionality of a PC or CPU board. It is added to the main board, which may house a one-chip microcontroller, to augment the device’s capabilities.

Commercially available personal computers and CPU boards come with predefined specifications intended for general use. However, these may not always meet specific user needs. Expansion boards offer a solution by adding extra functionalities.

Uses of Expansion Boards

In PCs and CPU boards, expansion boards are typically connected directly to the motherboard. While the PCI bus was once the standard interface for motherboards, it has largely been replaced by the faster PCI Express interface.

Expansion boards vary in type, including I/O boards for additional input/output capabilities, LAN boards for Ethernet connections, USB expansion boards for more USB ports, graphics boards for improved visual performance, soundboards for enhanced audio, and TV tuner boards for watching TV on a PC.

Principle of Expansion Boards

Desktop PCs generally have PCI or PCI Express slots on the motherboard for attaching expansion boards. However, due to physical limitations, notebook PCs typically cannot accommodate these boards.

Expansion boards require more than just hardware; they often need corresponding device drivers and, depending on the board, utility applications as well.

1. USB Expansion Board

USB expansion boards are commonly used to increase the number of available USB ports. While PCs typically come with a standard TYPE-A USB port, the number of ports is limited. Modern devices often use TYPE-C USB USB connectors, known for their reversible plug orientation and compact size. Expansion boards are sometimes used to add these TYPE-C ports.

2. IO Expansion Board

IO expansion boards are unique in that they can gather analog information such as temperature and humidity, convert it to digital data (A/D conversion), and input it into the CPU.

Other Information on Expansion Boards

1. PCI

PCI, short for “Peripheral Component Interconnect,” is a high-speed bus standard used not only for computer expansion slots but also in other applications. It operates at bus speeds of either 33 MHz or 66 MHz, with the 33 MHz speed being standard for 32-bit PCI.

2. PCI Express

PCI Express is an interconnect technology introduced in 2002, replacing PCI as the standard. It’s also used in aviation and automotive industries. To overcome the limitations of the PCI bus, such as difficulty in synchronizing data with faster clock speeds, PCI Express was developed as a more advanced standard.

What Is a 2-Phase Stepper Motor?

A 2-phase stepper motor consists of two phases, A and B, and is a type of motor that precisely controls the rotational angle and speed with pulse signals. It operates by rotating a fixed angle with each pulse, similar to the second hand of a clock, known as the basic step angle. The motor’s structure allows magnetic poles to form each phase, affecting the control method and operational angle per pulse.

Applications of 2-Phase Stepper Motors

2-phase stepper motors are instrumental in various applications requiring precise motion control, including clocks, industrial machines, robots, printers, slot machines, and camera lenses. They excel in applications needing synchronized motion with pulse signals but are not suited for heavy-load environments.

Principle of 2-Phase Stepper Motors

Stepper motors operate on set rotational speeds over time, known as operation patterns. These include a self-starting operation for constant speed rotation and manual operation patterns for gradually increasing speeds, forming a trapezoidal speed versus time graph. Motor performance is influenced by its characteristics, the mass of the object, the power supply, and the wiring method.

Types of 2-Phase Stepper Motors

2-phase stepper motors vary in design and functionality:

1. VR Motor Type

Characterized by an iron rotor and multiple convex teeth on both rotor and stator, though less common today.

2. PM Motor Type

Features a permanent magnet rotor and stator windings at 90-degree intervals, with a limit of about 20 poles due to magnetization spacing.

3. HB Motor Type

Includes a cylindrical magnet on the shaft, with two rotors offset by half a pitch and stator windings arranged every 90 degrees.

Wiring Methods of 2-Phase Stepper Motors

The performance of 2-phase stepper motors significantly depends on the wiring method:

1. Bipolar Wiring: Allows current to flow in both directions through the motor windings, offering higher torque but requiring a more complex drive circuit.

2. Unipolar Wiring: Directs current in a constant direction through two windings, simplifying the drive circuit at the expense of reduced torque.

What Is a 30-Degree Trapezoidal Screw?

Screws, crucial for assembling various products, come in different types based on their thread shapes. Among them are triangular screws with triangular threads, square screws, and trapezoidal screws, which have trapezoidal threads. Trapezoidal screws are distinguished by their thread angles, typically 30 degrees in Europe and 29 degrees in the United States.

Uses of 30-Degree Trapezoidal Screws

30-degree trapezoidal screws are utilized in diverse applications, including as adjustable screws in tool machines, operating equipment, lifting equipment, forklifts, injection molding machines, and assembly lines. They are preferred for their minimal backlash, high strength, ease of manufacturing, precision machining, and efficient conversion of rotational motion into axial movement.

Principles of 30-Degree Trapezoidal Screws

While triangular threads are commonly used in machine parts for their high frictional force, trapezoidal screws, with their unique thread design, offer high strength and are ideal for power transmission applications. These include feed screws for lathes and other machine tools, as well as valve openers and closers requiring precise motion transmission. The 30-degree angle of these screws is a standard in European trapezoidal screws, distinguishing them from other types.

Compared to square screws with square threads, trapezoidal screws are easier to manufacture and can be machined with finer pitch, making them ideal for applications requiring high-precision pitch. Their efficiency in converting rotational motion into axial movement also makes them suitable for jacks used in lifting heavy objects and for press screws.

What Is a Chain Guide?

A chain guide is a component that prevents meandering and vibration of a chain as it rotates and moves. It keeps the chain moving smoothly. Generally, “guide rail” is also used as a synonym.

For the above purposes, it is used in drive chains for power transmission applications and in conveyor chains for transporting goods and products along factory lines.

In addition, it can be a part to prevent a drive chain from falling off on bicycles, or a part to guard the rear sprocket and chain from getting caught in a rear sprocket and chain in motorcycles.

Uses of Chain Guides

Chain guides are used to guide drive and conveyor chains in industrial applications, and as guides for drive chains on bicycles and motorcycles.

In conveyor chain guides for industrial applications, they are used to prevent long, oscillating or meandering chains, to assist in straight movements, and to maintain the travel path of curved chains.

In motorcycle chain guides, chain guides attached to an automatic tensioner adjust the tension of the timing chain for the engine camshaft to ensure smooth operation.

Features of Chain Guides

Chain guides demonstrate their features of use in the following cases.

1. To Reduce Noise
   The use of a material with a low coefficient of friction in the parts that come into contact with the chain reduces the operating noise caused by chain vibration and other factors.
2. To Reduce Chain Wear
   The parts that come into contact with the chain are made of a self-lubricating, wear-resistant material, which makes contact with the chain smooth and reduces wear on the chain.

Chain guides generally have two types of guide rail shapes: convex, which protrudes in a mountain shape, and concave, which has a groove.

In the convex shape, the pin portion of the chain rests on the convex mountain portion and fits into the guide rail. Conversely, the concave type, the pins of the chain, and the plate on one side will fit in the concave groove.

Guide rails are made of ultra-high-molecular-weight polyethylene or other resins with properties, such as wear resistance, low friction, and self-lubrication. Some also use stainless steel or other materials in combination for reinforcement and to maintain the shape of the guide rail.

What Is a Protective Cover?

Protective Covers are used to protect the covers of vertical pipes such as manholes and hoardings. The upper end of a vertical water or sewage pipe has a hole for maintenance and cleaning, and if a load is applied to the covering, it may be damaged.

Protective coverings are classified according to their load capacity, and those that can withstand higher loads should be selected for installation in areas where large vehicles pass. The surface of the protective lid is installed so that it is at the same height as the road surface so that there are no steps on the road surface.

Uses of Protective Covers

Before wastewater from homes and businesses is discharged into the public sewer system, it is passed through a vertical pipe called a hoarding or pit. Once passed through the vertical pipe, large debris is allowed to settle out, preventing clogging of the sewer system.

Public sewers also have manholes for administrative purposes, and vertical pipes lead to waterways.

The tops of these vertical pipes have holes for internal maintenance and cleaning and are usually sealed with protective covers.

Principle of Protective Cover

The protective cover consists of a metal lid and a plastic base.

The load capacity of protective covers varies from product to product.

• T25: Withstands up to 25 tons. Used on roadways where vehicles of 14t or more pass through.
• T14: Withstands up to 14 tons. Used on roadways with few large vehicles.
• T8: Withstands up to 8 tons. Used on sidewalks and grounds where large vehicles will not pass over.

When installing the protective cover, the following points should be considered:

• To prevent the protective cover from coming into contact with the vertical pipe lid when it settles under load, a space of about 15 cm should be created between the lid of the vertical pipe and the protective cover.
• Install the protective cover so that its surface is at the same level as the road surface.

In order to meet the above requirements, the top opening of the vertical pipe is installed at a location that is excavated at least 15cm below the ground surface. A protective lid is placed on top of it, and the height of the pedestal is adjusted with granulated soil so that the surface of the protective lid is at the same height as the road surface.

Construction

When a new water pipe is installed or the protective cover needs to be replaced, a contractor is hired to install it.

The specific construction work for Protective Covers is carried out in the following steps:

1. Foundation: Dig down around the top of the pipe to make room for the Protective Cover. To prevent the foundation from settling, granulated crushed stone is placed and carefully compacted. Grain-size-adjusted crushed stone is a rock that has been crushed and sieved to a uniform grain size. Because of its strength, it is used for the foundations of roads and railroad tracks.
2. Installation: A pedestal and protective cover are placed on top of the foundation. Protective Covers should be installed level with the ground. If the ground itself is inclined, the inclination should be adjusted within the allowable inclination angle for each product.
3. Backfill: Backfill around the piping and protective cover using granulated crushed stone or asphalt.

Locking and Baghole Types

Protective Covers are divided into Locking and Baghole types, depending on how they open and close. When opening the protective cover for inspection or cleaning, it is helpful to keep in mind the differences between the two types to avoid confusion.

• The locking type has a mechanism to secure the lid. The locking mechanism varies from product to product. Some have a key operated by a flat-blade screwdriver, while others have a hook-type bridle that is opened and closed with a crowbar. When opening, check the locking mechanism and use the appropriate method to unlock. When closing, if the lid is misaligned, it may not lock. Close the lid and lock it so that it does not move, and check that it is fixed.
• The baghole type is not equipped with a mechanism to secure the lid. There is a hole called a blind hole in the part where the lid and the pedestal meet. The operation is simpler than the locking type, but since there is no lock operation when closing, even if the lid is misaligned, it may be overlooked. Please be aware that if the lid is left in place, it may cause rainwater to flow in through the gaps or bad odors to leak out.

What Is a Square Tank?

A Square Tank is a tank in the shape of a square box. They are generally made of polyethylene (PE), which is impact-resistant and environmentally friendly and can be used for a long time without rusting or corroding.

Various capacities and depths are available, including types with casters, types with drain plugs, deep types that can be transported with a forklift, types with hose stoppers and lids, and types that can be stacked. Larger square tanks have a slanted bottom in the center, and some have a slanted bottom structure that facilitates smooth drainage.

Some tanks are made of affordable polypropylene, while others are made of expensive FRP polyethylene and PTFE (polytetrafluoroethylene).

Uses for Square Tanks

Versatile Square Tanks are used in all areas of food processing, fisheries, fishing, textiles, industry, machinery, equipment, pharmaceuticals, logistics, civil engineering, construction, cement plants, steel mills, thermal power plants, and more.

Specific examples include:

• Compounding of construction materials, material storage
• Industrial container and packaging operations
• Food washing and preparation
• Storage of parts, tools, etc., and waste sorting containers in factories
• Storage containers for powders and other materials
• Fisheries processing from landing, sorting, and storage of marine products to live fish auction tanks at fish markets, etc.
• Shipping operations
• Transport, organization, and storage in factories
• Sewage receptacles

Other wide-ranging uses.

Principle of Square Tank

Polyethylene is the main material used for Square Tanks. However, polypropylene, FRP polyethylene, and PTFE (polytetrafluoroethylene) are also used.

The characteristics of each material are as follows:

• Polyethylene: This is the most widely produced synthetic resin material and is commonly used for multipurpose Square Tanks.
  It has excellent corrosion resistance, is impact resistant, and is easily recyclable. Stains can be easily removed by washing with water.
• Polypropylene (PP): This material is used to make Square Tanks called “Tubs” because it is easy to process and mass-produce at low cost.
  It is often used for small square tanks (50L~150L) because it is easy to process, inexpensive, and mass-producible. It has poor weather resistance and is vulnerable to ultraviolet rays such as direct sunlight.
• FRP Polyethylene: Weather-resistant, durable, and heat-resistant up to 80℃. It can also be used for chemicals with alkali components.
  It is resistant to impact, so it is easy to work in steel mills and thermal power plants. In cement factories, it can be completely recycled by burning it and mixing it with cement after use.
  This material is mainly used for large and expensive Square Tanks with a capacity of about 1000~3000 liters.
• PTFE (Polytetrafluoroethylene): Taking advantage of the excellent chemical resistance and purity of fluoropolymers, PTFE is used for the storage and mixing of high-purity chemical solutions used in semiconductor manufacturing equipment. It has high heat resistance and can be used at -240°C to 260°C.