月: 2022年12月

What Is a Non-contact Tachometer?

Non-contact tachometers are used to measure the rotation of rotating industrial equipment.

Rotating equipment is measured in a variety of ways, which is very important because its rotation can determine the capacity of the equipment.

However, it is time-consuming and dangerous to use a contact tachometer to measure the rotation of rotating equipment when there is no need for constant monitoring.

Non-contact tachometers are used for performance testing of rotating equipment which can be easily measured. There are various types of tachometers, from handy types to permanently installed types.

Uses of Non-contact Tachometers

The rotational speed of equipment which uses motors is very important.

For example, the performance of a roots blower can be determined from its rotation speed, allowing a performance test to be conducted before shipment to the customer. Non-contact tachometers are used to measure rotational speed. Because this type of equipment does not require constant monitoring, the non-contact type is sufficient.

However, even for instruments that require constant monitoring, the non-contact type is preferred because contact-type tachometers cannot detect accurate rotation speeds due to wear and tear caused by years of use.

Principle of Non-contact Tachometers

Non-contact tachometers come in a variety of types. The strobe type has been around for a long time.

This type of tachometer detects the number of rotations by matching the period of the light with the number of rotations. When the number of times the strobe light blinks synchronizes with the rotation speed, the object appears to stand still.

The number of rotations displayed at this time can be used to measure the number of rotations.

Other types of non-contact tachometers measure revolutions per minute (RPM) by emitting red visible light. A reflector-like object is attached to the shaft or pulley of a rotating device, and red visible light shines on it.

This allows the light to be reflected at regular intervals, making it possible to measure the number of rotations.

Non-contact tachometers can be made. To make a non-contact tachometer, combine a proximity sensor with an iron plate. Attach the iron plate to a pulley and attach the proximity sensor that reacts to the iron plate. The proximity sensor will then respond at a certain cycle, allowing the device to be used as a non-contact tachometer.

There are various types of non-contact tachometers. For most of them, it is important to know the diameter or circumference of the pulley or shaft in advance. This is because even with the same pulse, if the circumference changes, the rotation speed will also change.

What Is an Electrolytic Capacitor?

An electrolytic capacitor is a capacitor that uses an oxide film of aluminum or tantalum as a dielectric.

The general characteristics of an electrolytic capacitor are its high capacitance and voltage polarity. Electrolytic capacitors are classified into liquid (wet) and solid electrolyte types, as follows:

1. Liquid Electrolyte

• Aluminum electrolytic capacitor (wet)
• Tantalum electrolytic capacitor (wet)

2. Solid Electrolyte

• Manganese dioxide-based solid electrolytic capacitor
• Functional polymer electrolytic capacitor
• Organic semiconductor-based solid electrolytic capacitors
• Electric double layer capacitors (super-capacitors) are also sometimes included in the electrolytic capacitor category

Uses of Electrolytic Capacitors

Electrolytic capacitors are used as smoothing circuits in power supplies. They are also suitable for use as decoupling capacitors and backup capacitors.

Tantalum electrolytic capacitors are particularly suitable for decoupling capacitors because of their high capacitance and low impedance over a wide frequency band.

Principle of Electrolytic Capacitors

Using an aluminum electrolytic capacitor as an example, the mechanism of an electrolytic capacitor is described below.

Aluminum electrolytic capacitors use an oxide film (Al2O3) formed on the anode metal surface by electrochemical surface treatment as a dielectric. The surface of the aluminum foil is etched to form irregularities on the surface, effectively expanding the surface area and achieving a large capacitance.

The electrolyte is filled between the electrodes to extend the cathode, but since the electrolyte gradually leaks out of the package and evaporates over a long period, a decrease in capacitance over time is inevitable. This is especially noticeable at high temperatures, so to extend the life of the product, it is necessary to avoid increases in ambient temperature.

The relative dielectric constant of aluminum oxide formed on the surface of aluminum foil is 7~10, and its dielectric breakdown voltage is 500kV/mm or higher. That is, aluminum electrolytic capacitors utilize the depletion layer capacitance of the reverse polarity of this diode, but because they utilize this reverse polarity, the applied voltage of aluminum electrolytic capacitors is limited to one direction. This is the reason why reverse voltage cannot be used.

Tantalum electrolytic capacitors use tantalum pentoxide as the dielectric and manganese dioxide as the electrolyte. Since the electrolyte is solid, leakage does not occur. Tantalum electrolytic capacitors have an advantage over aluminum electrolytic capacitors in terms of life expectancy.

Types of Electrolytic Capacitors

All types of electrolytic capacitors are characterized by their high capacitance, but there are applications that take advantage of the characteristics of each type.

1. Aluminum Electrolytic Capacitor

Aluminum electrolytic capacitors are widely used in power supply circuits because of their large capacitance and ease of production. Since they do not have good high-frequency characteristics, they are used in smoothing circuits after rectifying commercial power supplies. Despite their compact size, capacitors have large capacitance and are available in a wide variety of types. Another feature of these capacitors is their relatively low price.

2. Tantalum Electrolytic Capacitor

Although small, these capacitors have a reasonable capacitance, but since tantalum is a kind of rare metal and expensive, large capacitance capacitors are not manufactured. The upper limit is around several hundred μF. Because of its excellent high-frequency and temperature characteristics, it is used in smoothing circuits for switching power supplies that turn current on and off at high frequencies.

As described in the section “Uses of electrolytic capacitors,” they are also used as decoupling capacitors to absorb spike noise in power supply circuits.

3. Electric Double-Layer Capacitors

Because of their relatively high internal resistance (several hundred mΩ to a hundred Ω), they cannot be used for ripple absorption or other purposes. They are mainly used as secondary batteries for power supply backup. Since the capacitance is very large and there is no limit to the number of charge/discharge cycles, it is used for backup of memory circuits, etc.

What Is an Electromagnetic Actuator?

Electromagnetic actuators are devices that convert electrical energy generated by electromagnetic phenomena into mechanical action, such as rotational or linear motion. These actuators play a crucial role in various industries, enabling precise motion control in machinery through motors and solenoids. Utilizing electromagnetic actuators requires a deep understanding of electromagnetic fields and the analysis of structures and mechanisms.

Applications

Electromagnetic actuators are integral across electrical and electronic equipment manufacturing, medical devices, and analytical machinery. They are prevalent in the automation of industrial machinery, enhancing the precision of medical instruments, and the operation of semiconductor manufacturing equipment. Their versatility allows for both translational and rotational movements, making them ideal for controlling the motion of machines, including the operation of switches and valves.

Operating Principle

The working principle of electromagnetic actuators is grounded in Faraday’s Law, utilizing the magnetic force generated by electric current flowing through an internal coil to move a movable iron core or plunger. This magnetic interaction facilitates the conversion of electrical energy into mechanical motion, allowing for both sustained rotation in motors and direct linear motion in solenoids. The strength of the magnetic force is directly proportional to the electric current, offering control over the motion based on current modulation.

Additional Insights

• Comparison with Cylinders and Motors: Actuators, including electromagnetic types, convert energy into motion. Unlike pneumatic or hydraulic cylinders, electromagnetic actuators offer more precise control and energy efficiency, reflecting a growing preference in industrial applications.
• Motion Controllers: In industrial settings, electromagnetic actuators are part of comprehensive systems that include sensors, servo control units, and communication systems for integrated motion control. Specialized companies often provide system support and components, such as control software and ICs, to manage the sophisticated digital aspects of motion control.

What Is an Electrostatic Precipitator?

Electrostatic precipitators are so-called filter-like devices that collect fine particles and dust suspended in the air and remove them from the air by using electricity.

This device turns the polluted air in the vicinity into clean air, which is very important for purifying the soot and smoke generated by factories during operations.

Compared to other dust collectors, Electrostatic precipitators are more efficient in collecting suspended particulates and are used at many sites.

Uses of Electrostatic Precipitators

Electrostatic precipitators are used at manufacturing and processing sites that handle fire or generate soot and smoke.

Typical examples are large incinerators used to process waste materials and steel mills.

These plants generate large amounts of smoke (soot) containing substances that are harmful to humans and the environment during the processing and manufacturing processes.

In addition, the air at tunnel excavation sites becomes easily contaminated by particulate matter. Electrostatic precipitators are extremely important to keep the air at these sites clean and safe, even in confined spaces.

Principle of Electrostatic Precipitators

The principle of an Electrostatic precipitator is to remove fine particles and dust from the air or gas to be collected by attracting them to the collecting electrodes by electrical force (Coulomb force).

Electrostatic precipitators have a discharge electrode and a collecting electrode, and applying a high voltage between them produces a corona discharge.

The corona discharge causes the surrounding air to have a negative charge, and these negative ions attach to the fine particles and dust in the air, causing the fine particles to have a negative charge.

These negatively charged particles and dust are attracted to the positively charged collecting electrodes.

Particles and dust collected on the collecting electrodes are removed from the equipment by beating them with a hammering device, brushing with a scraping device (dry type), or washing them out with water or mist spray flushing (wet type).

In addition to Electrostatic precipitators, cyclonic precipitators use centrifugal force and fabric bag filters. The advantage of Electrostatic precipitators is that they have a dust collection efficiency of up to 99.9% and can remove particles as small as submicron size (0.01 micrometer).

What Is a Watt-hour Meter?

A Watt-hour meter is an electrical device used to measure the amount of electricity used by a consumer. By measuring the amount of electricity used by factories and residences, Watt-hour meters automatically calculate electricity rates for customers. Watt-hour meters have built-in ammeters and voltmeters, whose values are used to calculate the amount of electricity used. Watt-hour meters have been conventionally equipped with an aluminum disk that rotates to measure the amount of electricity used.

Uses of Watt-hour Meters

Watt-hour meters are used to measure the amount of electricity consumed by customers. Watt-hour meters are generally found on the exterior walls of homes. By looking at the value displayed on a Watt-hour meter, the amount of electricity used by a household can be calculated. The electric company checks the value displayed and calculates the monthly charge.

Meters are installed not only in homes, but also in factories, commercial facilities, and other buildings that use electricity. All buildings that use electricity are required to have the amount of electricity used checked and are obliged to pay electricity charges.

Principle of Watt-hour Meters

Electricity consumption (Wh) is calculated by continuously measuring the electric power (P) used per second, dividing it into hourly units, and adding these values together to calculate the amount of electricity used for a given period of time.

There are two types of Watt-hour meters in common use: inductive and electronic.

Inductive Watt-hour meters consist of a current coil, a voltage coil, an aluminum disk, and a measurement device. The magnetic force of the current coil and voltage coil connected to the load generates electromagnetic induction, which rotates the aluminum disk for measurement.

The electronic Watt-hour meter does not use the mechanism of a rotating disk. In the electronic type, a built-in electronic circuit measures the current and voltage of the load and calculates the amount of electric energy. The electronic type has a less mechanical structure and is less prone to breakdowns. It has the advantage of operating for relatively long periods of time without problems.

Recently, smart meters have come into use, allowing for more detailed measurement of electricity consumption as they provide the ability to remotely check Watt-hour meter readings. 

Smart Meters for Watt-hour Meters

Analog induction-type Watt-hour meters have traditionally been the norm. These meters have a structure in which a disk rotates when electricity is used, allowing the amount of electricity to be measured by the number of revolutions. In recent years, digital Watt-hour meters called smart meters are beginning to replace analog meters. Smart meters can send data to remote locations, allowing users to check the amount of electricity they are using even in remote areas. These meters also provide “electricity visualization,” by digitally displaying the amount of electricity used, and can be expected to increase users’ awareness of their energy consumption and the need for energy conservation. In terms of electricity contracting, because the breaker is built into the smart meter, there is no need to replace it, as in the past. In addition, the electric company will be able to easily monitor the status of electricity usage, which may lead to cost reductions and even lower electricity rates by reducing wasteful power generation. Conversely, a demerit of smart meters is the possibility of the invasion of consumers’ privacy. Lifestyle patterns, family composition, and other information can be inferred from electricity usage data generated by smart meters.

What Is a Power Monitor?

Power monitors are devices that monitor power consumption in real time to save energy, primarily to reduce environmental impact and cut costs.

Continuous monitoring of the target system to determine its power consumption in real time leads to energy savings for facilities.

It enables facility operators to know when power consumption is high by comparing it with the system’s operating data.

Uses of Power Monitors

Power monitors are used to measure power consumption over time.

Power monitors are used in industries such as manufacturing, mining, electricity, gas, and heating, and by places of business such as department stores, hotels, schools, hospitals, office buildings, government offices, amusement parks, convenience stores, fast food restaurants, family restaurants, and fitness clubs.

Power monitors can measure power (active, apparent, reactive); integrated power (active, apparent, regenerative, reactive); optional integrated active power; instantaneous, maximum, and minimum voltage values; instantaneous and maximum current values; power factor, and frequency.

Power monitors have a wide measurement range, from watts (W) to megawatts (MW).

Power monitors have two power integration pulse outputs to measure active power and regenerative or reactive power.

Power monitors also offer a full range of communication functions, including RS-485 communication, MODBUS, PC Link, UPM01 protocol, and 920 MHz radio communication.

Power monitors provide powerful support for energy conservation analysis and can measure 15 different power elements, including integrated power consumption, in a single unit, which is also available in a compact type.

Power monitors are also compatible with 440 V and 3-phase 4-wire systems. Various measured data can be transmitted to personal computers and other devices via communication, and pulse output of accumulated power is also possible.

Some power monitors use a dedicated 5A current transformer (CT), which can detect the secondary side current from the CT used in the existing meter. Because existing CTs can be used, there is no need to install new CTs, and installation costs can be reduced without cutting power lines.

What Is a Mold Release Agent?

Mold release agents are necessary when melting metals and other materials for mold forming. You can imagine it as a waffle. Before making a waffle, the mold is coated with oil. That is the mold release agent. Similarly, melted metal is poured into a mold and formed. In other words, it is used to increase the release from the mold when the mold is formed.

Molds are useful for quickly producing large quantities of the same shape. However, simply pouring a liquid material into a mold and molding it will not allow it to be cleanly removed from the mold and it will stick to the mold.

Uses of Mold Release Agents

Mold release agents are always applied when molding. However, there are different types of release agents depending on the form.

One is an external release agent that is applied to the mold, like oil or margarine, used for food, and the other is an internal release agent that is mixed with the material. Other types include water, emulsion, solvent, paste, and oil types, as well as baking and spray types classified by usage.

Among them, ingredients vary greatly in effectiveness. Fluorine-based products require less effort and have lower lubricity. Silicone-based products have good lubricity, but require more time and effort to clean.

Principle of Mold Release Agents

Mold release agents can be roughly divided into wax-related, silicone-related, and fluorine-related.

Wax release agents form layers between the mold and the molded product, causing delamination between the layers. This is called delamination. Although it is characterized by excellent paintability, the amount of transfer is large and the mold can easily become dirty.

Silicone-related products also undergo delamination in the same way as wax-related products. Silicone oil has excellent lubricity, so it has a very high mold release property. However, the amount of transfer is also high, and there is a problem that the molds get dirty easily.

Fluorine-related products utilize the non-adhesiveness of fluorine. Intermolecular contact causes interfacial delamination. This is one of the reasons why the film thickness is thin and the amount of fluorine used is small. Fluorine is often used in combination with silicone because it is difficult to provide high lubricity as a stand-alone material.

As mentioned in the transfer story, the mold release agent may remain in the mold. Moderate cleaning is necessary after a certain amount of use.

What Is a Diaphragm Pressure Gauge?

A diaphragm pressure gauge is a device designed to measure pressure using a diaphragm, a flexible membrane that responds to changes in pressure. This type of gauge is commonly utilized for monitoring the pressure of both liquids and gases in various industries, offering high accuracy and reliability essential for precise process control and measurement.

Known for their robustness, durability, and stability, diaphragm pressure gauges excel in challenging, high-temperature, high-pressure environments. Accommodating any pressure range, their versatility and cost-effectiveness make them suitable across many applications.

Applications

Diaphragm pressure gauges find applications across diverse sectors:

• Industrial Processes: Essential for quality control and process efficiency in manufacturing, they monitor pressure in equipment such as presses and molding machines. In the chemical industry, these gauges ensure safe and efficient chemical reactions by controlling reactor pressure.
• Energy Sector: Critical in power generation, they monitor boiler and turbine pressures for energy efficiency and plant safety. Nuclear facilities rely on them for reactor pressure management.
• Construction Machinery: Used in hydraulic systems of cranes and bulldozers to enhance operational safety.
• Environmental Equipment: Vital in water treatment plants for monitoring centrifugal separators and pressurizing machinery, ensuring proper functionality.

Operating Principle

The operation of a diaphragm pressure gauge involves measuring the deformation of a diaphragm caused by applied pressure. Made from metal or synthetic materials, the diaphragm deforms under pressure, a change that is transmitted to a measuring mechanism. This mechanism, utilizing levers, springs, or sensors, converts the deformation into readable pressure values.

Selection Criteria

Selecting a diaphragm pressure gauge involves several considerations:

• Material: The diaphragm’s composition should withstand the measured medium’s pressure and potential corrosiveness. Stainless steel and Hastelloy are common choices.
• Pressure Range: The gauge must accommodate the specific pressure range of the application to ensure accuracy and prevent damage.
• Maximum Allowable Pressure: It’s crucial to choose a gauge that won’t be compromised by exceeding its maximum allowable pressure, to maintain safety and functionality.
• Mounting Diameter: The gauge should fit the installation site’s specifications, aligning with the piping and connections for seamless integration.

What Is a Dust Collector?

Dust collectors are machines used to remove dust, sediment, and other debris. They can be used at sewage treatment facilities and drainage facilities to rake, collect, and remove debris from rivers and streams.

There are two types of dust collection methods: the rake type and the rotating net type. The choice is based on the uses of the machine and the location where the dust collector will be installed.

In the rake type, pins are attached around the roller part, which rotates to break up the debris and rake it up from the water surface. In the rotating net type, debris is captured by rotating a net with a mesh that matches the size of the object to be removed.

In conjunction with a screen, it also prevents fine debris from passing through.

Uses of Dust Collectors

Dust collectors can collect and remove dust and debris, so they are used to remove debris and accumulated debris from rivers and streams where there is a flow toward the mouth of the river.
They are used in drainage facilities, etc., so that the natural flow of water can be discharged without interrupting the flow of water.
They are also used in various other places, such as agriculture, industrial water, water supply, sewage treatment facilities, and power plants.

Dust collectors can be equipped with a variety of functions to suit the uses of the equipment, such as using a pump to suck up the waste or a conveyor belt to carry the waste out of the area efficiently.

Principle of Dust Collectors

Dust collectors consist of a rotating cylindrical roller called a rake with needles attached to its circumference, which collect dust and dirt by breaking it into small pieces.
Since multiple rakes can be attached to the chain and rotated to use the rakes continuously, even when the amount of trash is large, multiple rakes can be installed to rake up the debris efficiently.

In addition, screens and nets are available in coarseness from fine to large, and by changing the size according to the object to be removed, the captured debris can be removed without letting it escape downstream.

What Is a Waterproof Connector?

Waterproof connectors are connectors that prevent water from entering the electrical wiring and prevent electrical problems, such as shorts between terminals from occurring, even if the connector is exposed to water.

Waterproof connectors consist mainly of a connector body and a rubber packing that fill the gap. In order to prevent water from entering the connector, the male and female connectors are mated in a press-fit manner, with no gap between the male and female connectors. This makes the removal of waterproof connectors harder and more difficult than non-waterproof connectors.

Some products have a lever on the connector to improve the reliability of waterproof connectors, and by lowering the lever after mating the male and female connectors, the connector will not come off unless the lever is raised again. Waterproof connectors are used in places where waterproofing and dustproofing are required, such as cars and motorcycles that are used in the rain, as well as ships and machine tools.

Uses of Waterproof Connectors

Waterproof connectors are used in places where a large amount of electrical wiring is required and where water and dust resistance is required. For example, they are used for products that are stored in the rain or used in the rain, such as cars and motorcycles.

Other than that, it is also useful for products such as machine tools that use a large amount of cutting oil and are constantly exposed to a humid environment while producing a large amount of chips and ships that may be exposed to seawater. They are also often used in machines used in clean rooms, such as machines for semiconductors.

Waterproof connectors have different standards for waterproof performance, and since different products have different standards for waterproofness. It is necessary to check them carefully according to the application for which they are used.

Principle of Waterproof Connectors

Waterproof connectors generally consist of a connector body that mates with the mating device and a rubber packing that fills the gap to prevent water from entering. The rubber packing is attached like a plug to fill the hole not only on the mating surface of the connector but also on the connection surface with each wire that enters the connector.

In many cases, when wires and terminals are crimped, the rubber plugs are rolled in and crimped together. Both the male and female sides contain similar packing, and when the connectors are mated, the packing eliminates the gap between each other to maintain airtightness. For this reason, waterproof connectors are more difficult to attach and detach. firmly when mated than non-waterproof connectors.

Some products have a lever attached to the connector, which must be physically raised or lowered to prevent it from coming off due to vibration after mating.

Types of Waterproof Connectors

There are many types of waterproof connectors, depending on the connection method.

1. Permanent Engagement Type

Permanently engaged waterproof connectors can be purchased at general home improvement stores. They are mainly used for devices such as motorcycles and cars. The always engaged waterproof connector has a rubber packing inside to provide high waterproof performance.

Although it is possible to install the connector as if you were a carpenter, since the male and female connectors are mated without a gap for waterproofing, it requires a little trick to disengage the connector once it is engaged. In the worst case, if the connector is removed in the wrong way, the connector itself will break, making it impossible to demonstrate its waterproof performance, so care must be taken.

Also, since it is made of plastic, it is slightly less weather resistant.

2. Plug Type

Metal plug-type waterproof connectors are often used for industrial applications. These are very easy to install and remove because the male and female plugs mate with screws.

Since they are made of metal, they are strong and reliable, and can be used outdoors without problems. Panel-mounted type is often used for penetrating through machines and control panels.

They are pre-installed on the back of the machine, etc., and can be easily connected by tightening screws and mating. These waterproof connectors are also called “cable grants.”

Other Information on Waterproof Connectors

Importance of Waterproof Connectors

When connecting numerous wires one by one in an area where water and dust resistance is required, it is very time consuming. In addition, if all the wires are in an area that may be disassembled or repaired in the future due to damage or short-circuit caused by exposure to water. It will be impossible to disassemble or repair the entire unit without disassembling the entire unit.

Therefore, it is common to use a component called a “connector” to divide the wire into appropriate sections and connect them as a single wire by mating the connectors together. Waterproof connectors are useful in outdoor locations where water or dust may enter.