Electronically Commuted Motors — Higher Efficiency

Restaurant owners have long been facing operational challenges. These include high energy costs, limited kitchen space, and equipment downtime. For addressing these challenges and improving restaurant productivity, the owners have turned to commercial kitchen equipment. Most of such kitchen equipment has an electric motor at heart, whose performance dramatically impacts how the equipment operates and how it mitigates the above challenges.

It is imperative that owners increase their productivity while reducing their costs, considering their profit margin usually falls between three and five percent. This requires a clear understanding of the connection between the motor and the equipment. Doing so not only reduces the operating costs but also ensures a smoother running operation.

Energy costs happen to be a major concern in the restaurant industry. Commercial kitchen equipment is uncommonly hard on the electricity bill, being typically robust and energy-intensive. According to the US Energy Information Administration, consumption in restaurants is typically three times more per square foot than any other comparative commercial enterprise. This is because restaurants use specialized equipment that has a high power demand, and they operate for extensive hours, thereby consuming huge amounts of energy.

Therefore, purchasing and using high-efficiency, higher energy star-rated restaurant equipment is one of the easiest ways to improve the bottom line. However, as a motor is at the heart of each piece of equipment, it offers a greater choice. In fact, restaurant operators can improve on this further by taking a proactive approach and selecting equipment that has an electronically commuted motor or ECM. They can even consider retrofitting existing equipment with ECMs for a more favorable option.

The reason for the above decision is that an ECM operates more efficiently as compared to what a traditional induction motor does when running restaurant equipment such as ovens, walk-in coolers, mixers, and fryers. Depending on the use cycle, equipment with ECM technology can save more than 30% in annual energy costs. This improves the bottom-line savings and improves the profitability of a restaurant.

A microprocessor and electronic control help to run an ECM. Compared to regular induction motors, this arrangement offers higher electrical efficiency. It also offers the possibility of programming the precise speed of the motor. Moreover, ECMs can maintain high efficiency across a wide range of operational speeds.

Apart from the higher efficiency, ECMs are precise and offer variable speeds, which in fans means an unlimited selection of airflow. A properly maintained airflow during changes in the static air pressure brings important benefits to the restaurant, especially for its hood exhausts and walk-in coolers. The higher efficiency of ECMs leads to reduced heat in the refrigerated space, thereby reducing the equipment runtime.

Forward-thinking original equipment manufacturers are re-engineering their designs and products to include ECMs for delivering smaller and more versatile equipment. Compact motors such as ECMs, are gaining wider recognition and appreciation as they improve the power density of their equipment. Compared to equipment with traditional induction motors, those using ECMs offer the same output, but with a much smaller footprint and lower weight.

Industrial Automation with Single-Pair Ethernet

Efficiency is the fundamental concern for the successful implementation of any factory automation solution. For this, it is necessary to implement control and power components that consume the least possible amount of energy over their lifetime. However, for the actual realization of those savings, it is necessary for proper installation of the system.

This is where the advantages of the SPE or Single Pair Ethernet technology really come across. The technology transfers power and data over the same thin-wire cable. Not only does this save installation costs up-front, but it takes much less to maintain and upgrade the system over time. Phoenix Contact offers their ONEPAIR series for standardized SPE solutions. The ONEPAIR series has two main types of connectors, and they each serve a specific application.

In numerous industries and fields, the IP20 connectors and patch cables enable effective data transmission. This includes building and factory automation, where it is common to achieve a transmission rate of 1 Gbps for a distance of 1000 meters.

The other is the M8 device connectors, rated at IP67. They can transmit power and data safely and quickly from the OT to the IT. This is a new standard in compact connections, which can withstand harsh environments.

SPE or single-power Ethernet is high-performance, parallel transmission of power and data via Ethernet over a single pair of wires. The technology typically carries data and power through PoDL or Power over Data Line starting from the sensor and carrying through right up to the cloud. For barrier-free networking of a wide range of connectors, cables, and components, it is necessary to deploy connectors with standardized pin patterns. For this, Phoenix Contact offers standard connectors, ranging from IP20 to IP6x.

Apart from being ideally suited for a wide range of applications, the SPE is the basis for all Ethernet-based communication. Not only does it enable smart device communication, but it also opens up newer fields of application. SPE has great transmission properties, can span long distances, and optimally supports future-proof network communications. With a trend for miniaturized, resource-conserving devices, SPE offers space-saving cables and electronics.

SPE brings many benefits to its users. It can provide transmission speeds of over 10 Gbps over a single pair of wires. This helps to reduce data cabling while avoiding media breakdowns and device failures, from the field to the cloud. The user has the freedom to establish networking with a consistent structure base of Ethernet, eliminating the need for gateways. With SPE, the cabling is easier and saves time, as the user needs to guide and connect only two wires. They can use the 10Base-TIL standard Ethernet cabling for ranges up to 1000 meters.

The IEEE 802.3 defines the SPE standards. Presently, there are five standards for different transmission speeds and distances. Further standards are under discussion. The IP20 compact male connector series from Phoenix Contact are in accordance with IEC 63171-2 and are ideally suited for building and control cabinet cabling. The M8 or IP67 contacts from Phoenix Contact are in accordance with IEC 63171-5, providing robust and industrial-grade connections.

What is I3C Interface Communication

I2C is a popular serial communication protocol, with I3C being an improved version. Embedded systems use this new protocol for achieving significantly higher data throughput and features that are more advanced than what I2C offers. Designers and engineers can use I3C for improving the functioning and performance of their designs while adding more features such as in-band interrupts, hot-join, and high data rate modes. With I3C being backward compatible, it can communicate with legacy targets using the present I2C protocol.

There are some major differences between I3C and I2C. While I2C works on bus speeds of 100 kHz, 400 kHz, or 1 MHz, I3C operates with bus speeds up to 12.5 MHz. The increase is due to I3C using push-pull outputs, which switch between push-pull drivers and open-drain outputs depending on the state of the bus. I3C uses open-drain driving during arbitration or initial addressing where multiple targets are controlling the line at the same time. I3C uses the push-pull driver for unidirectional communication, and no other device is expected to communicate simultaneously.

The voltage range of operation of I2C is between 3.3 and 5 VDC, and I3C operates with supply voltages of 1.2, 1.8, and 3.3 VDC, with the possibility of other voltages in between. Unlike 12C, I3C does not require external pull-up resistors, as the main controller on the bus provides these.

I2C uses static 7-bit and 10-bit addressing of target devices. On the other hand, I3C makes use of dynamic 7-bit addressing, where the active controller designates each target with an unambiguous address to prevent collisions with addressing. In contrast, I2C requires the designer to keep track of the current addresses to prevent assigning the same address to two or more devices. I3C assigns addresses dynamically during bus initialization.

I2C has no mechanism for a target to tell the controller that data is ready unless it uses an extra IO line. However, devices in I3C can signal an interrupt by using the serial data and serial clock lines, thereby making the protocol truly two-wire. I3C also uses this in-band signaling for implementing hot-join functionality. This allows new devices to join once the initial address assignment is over.

I2C allows multi-controller buses. Here, although multiple devices can operate as controllers, only one of them can actively communicate at a time. On the other hand, I3C can have only one active controller, while other capable devices can request to become active controllers on the bus. This device can then become the secondary controller. If the secondary controller is no longer acting as an active controller, it starts functioning as an I3C target.

I3C is backward compatible with I2C. However, for successful communication, the targets in the I2C protocol must have a 7-bit address, and must not use clock stretching. The new protocol suggests the I2C targets contain 50ns filters on their inputs. By meeting these requirements, I2C targets become compatible with the I3C bus. On the other hand, a few I3C devices may also operate as I2C targets, until they have been assigned a dynamic address. When working in the I2C mode, the I3C devices have static communication addresses.

New Graphene Sensors

While more advanced technology sectors have been late in adopting graphene, it finds plenty of interest in both lower- and high-tech applications. One of these applications is sensors based on graphene. Different industry sectors have steadily been using these sensors.

This is because graphene can be the basis of an effective sensing platform. Several interesting applications manifest this in many ways. Of these, the biosensor subsector is especially notable in attracting heavy investment. This trend is likely to continue even beyond 2022.

With graphene properties being exhaustively documented, many are now aware that they can do a lot with graphene and that many applications can benefit from its properties. Although many of these aspects are often subject to some hype, the fundamental properties of graphene make it a superior material of choice. This is primarily of account of graphene being suitable as an active sensing surface in many sensing applications.

The major advantage of graphene is its inherent thinness. This allows sensing devices made from graphene to be far more flexible and smaller in comparison to many other materials. In addition, graphene forms a very high-end active surface area.

In applications involving sensing, a high surface area is beneficial as it allows interaction with a larger range of molecules like different gases, water, biomolecules, and many other molecular stimuli. With graphene being an active surface, it is possible to attach a number of different molecular receptors and molecules to a sheet of graphene. This helps to create sensors that can detect specific molecules.

However, graphene has more advantages. Because of the high electrical conductivity of graphene, its high charge transfer properties, and high charge carrier mobility, sensors made from graphene exhibit very high sensitivity. That means, graphene sensors will generate a detectable response even from a small interaction with the environment. This happens because the excellent properties of graphene help in changing the resistivity across the graphene sheet with each small interaction. Therefore, graphene sensor help to detect even the smallest amounts of stimuli from the environment.

Because of their innate thinness, it is possible to make graphene-based sensors in small form factors, while retaining their highly sensitive sensing characteristics. It is also possible to tailor the sensors chemically for detecting a range of stimuli from the environment. This characteristic has led to the generation of much commercial interest in developing various graphene-based sensors for a variety of commercial markets involving many applications.

For instance, Paragraf has a graphene-based Hall-effect sensor that can measure changes in a magnetic field using the Hall effect. Therefore, this has increased the possibility of adding many new and interesting application areas to those that graphene sensors had not ventured into so far.

In the past year, Paragraf has demonstrated that Hall-effect sensors based on graphene are highly sensitive. They can measure currents flowing in batteries within electric vehicles for monitoring their status. Paragraf makes these sensors by depositing single layers of contamination-free graphene directly on a wafer. They repeat this following standard semiconductor manufacturing processes. This has allowed them to make several volume applications possible now, including those for fast and sensitive biosensors for detecting biomarkers within liquid samples.

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Haptic Skin Sensors

Although great technological advances are taking place to engage our eyes and ears in the virtual worlds, engaging other senses like touch is a different ballgame altogether. At City University in Hong Kong, engineers have developed a wearable, thin electronic skin called WeTac. It offers tactile feedback in AR and VR.

At present, there are several wearable devices with designs that allow users to manipulate virtual objects while receiving haptic feedback from them. However, not only are these devices heavy and big but also require tangles of wire and complex setups.

In contrast, the WeTac system is one of the neatest arrangements among all others. The engineers have made it from a rubbery hydrogel that makes it stick to the palm and on the front of the fingers. The device connects to a small battery and has a Bluetooth communications system that sits on the forearm in a 5-square-centimeter patch. The user can recharge the battery wirelessly.

The hydrogel has 32 electrodes embedded in it. The electrodes are spread out all over the palm, the thumb, and the fingers. The system sends electrical currents through these electrodes to produce tactile sensations.

According to the WeTac team, they can stimulate a specific combination of these electrodes at varying strengths. This allows them to simulate a wide range of experiences. They have demonstrated this by simulating catching a tennis ball or generating the feel of a virtual mouse moving across the hand. They claim they can ramp up the sensation to uncomfortable levels, but not to the extent of making them painful. This can give negative feedback, such as a reaction to touching a digital cactus.

According to the researchers, they can pair the system up with either augmented or virtual reality. They can thus simulate some intriguing use cases. For instance, it is possible to feel the rhythm of slicing through VR blocks in Beat Saber, or catch Pokemon while petting a Pikachu in the park in AR.

Using the WeTac system, it may be possible to control robots remotely or transmit to the human operator the tactile sensations of the robot as it grips something.

Syntouch has a new tactile sensor that performs three important functions. First, it measures the impedance using a flexible bladder placed against an array of sensing electrodes fixed in a rigid core. This arrangement helps to measure deformity, somewhat like the human finger, using its ductile skin and flesh against the rigid bone structure inside it. The finger uses its fingernails to cause bulges in the skin for detecting shear forces.

Second, the tactile sensor registers micro-vibrations using a pressure sensor that the sensor core has mounted on its inside. This enables measurements of surface texture and roughness. The fingerprints are very crucial here, as they can interact with the texture.

Third, the sensor has a thermistor. Its electrical resistance is a function of temperature. Just like the human finger can sense heat, the sensor also generates heat, while the thermistor allows it to detect how it exchanges this heat when the finger touches an object.

Precision RH&T Probe Using Chilled Mirror

The Aosong Electronic Co. Ltd, with a registered trademark ASAIR, is a leading designer and manufacturer in China of MEMS sensors. They focus on the design of sensor chips, the production of wafers, sensor modules, and system solutions. They have designed a sensor AHTT2820, which is a precision relative humidity and temperature probe.

ASAIR has based the design of AHTT2820 on the principles of a cold optical mirror. It directly measures humidity and temperature. Contrary to other methods of indirect measurements of humidity through resistance and capacitance changes, AHTT2820 uses the principles of a cold optical mirror. It can directly measure the surrounding humidity. It is an accurate, intuitive, and reliable sensor.

ASAIR uses a unique semiconductor process to treat the mirror surface of this high-precision humidity and temperature sensor. It uses platinum resistance to measure the temperature by sensing the change in the resistance due to a change in temperature. This gives the high-precision humidity and temperature sensor long-term stability, reliability, and high accuracy of measurement. The sensor features a fast response speed, a short warm-up time, and an automatic balance system.

Users can connect the sensor to their computer through a standard Modbus RTU communication system. It can record data, display the data, and chart curves. The precision RH&T probe provides direct measurement of temperature and dew point. Powered by USB, the split probe is suitable for various scenarios.

The AHTT2820 is a chilled mirror dew point meter that directly measures the dew point according to the definition of dew point. Various industries widely use it. They include food and medicine production industries, the measurement and testing industry, universities, the power electronics industry, scientific research institutes, the meteorological environment, and many others.

The probe uses its optical components to detect the thickness of frost or dew on the mirror surface. It uses the detection information for controlling the temperature of the mirror surface for maintaining a constant thickness of dew or frost. It uses a light-emitting diode to generate an incident beam of constant intensity to illuminate the mirror. On the opposite side, the probe has a photodiode for measuring the reflected intensity of the incident beam from the light-emitting diode.

The probe uses the output of the photodiode for controlling the semiconductor refrigeration stack. Depending on the output of the photodiode, the system either heats up or cools down the semiconductor refrigeration stack. This helps to maintain the condensation thickness of moisture on the surface of the mirror.

As it reaches the equilibrium point, the rate of evaporation from the mirror surface equals the rate of condensation. At this time, the platinum resistance thermometer embedded in the mirror measures the temperature of the mirror, and this represents the dew point.

Under standard atmospheric pressure, it is possible to obtain the related values of absolute humidity, relative humidity, water activity, and humid air enthalpy through calculation after measuring the ambient temperature.

The probe can measure temperatures from -40 to +80 °C, with an accuracy of ±0.1 °C. It measures humidity from 4.5 to 100%RH at 20 °C, with an accuracy of ±1%RH at <90%RH.

A Wheel-to-Leg Transformable Robot

With the general audience preferring to engage in the search for anthropomorphization, the popularity of biped and quadruped robots has been growing. At the Worcester Polytechnic Institute, researchers have innovated a robotic system that they call the OmniWheg—a robotic system that adapts its configuration based on the surrounding environment that it is navigating. They introduced this robot in a paper in the IEEE IROS 2022, and pre-published it on arVix. OmniWheg has its origins in an updated version of whegs, which was a mechanism with a design to transform the wings or wheels of a robot into legs.

Although the researchers would have liked to make the robot capable of going everywhere they go, they found the cost of legs to be very high. While evolution has provided humans and animals with legs, the researchers found that a robot with legs would be highly energy inefficient. While legs could make the robot more human or animal-like, they would not be able to complete tasks quickly and efficiently. Therefore, rather than develop a robot with a single mechanism for locomotion, the team proceeded to create a system that switched between various mechanisms.

The team found that about 95% of the environments at homes and workplaces are flat, while the rest are uneven terrains that require transitioning. Therefore, they went on to develop a robot that performs with a high-efficiency wheel-like arrangement for 95% of the cases, specifically transforming to the lower-efficiency mechanism for the remaining 5%.

The researchers, therefore, created a wheel that changed its configuration for climbing stairs or for circumventing small obstacles. For this, they utilized the concept of whegs, wing-legs, or wheel-legs, which is popular in the field of robotics.

In the past few years, the team developed and tested several wheel-leg systems. However, most of them were not successful, as the left and right sides of the wheel-leg system would not coordinate well or align properly when the robot tried climbing stairs.

Finally, the team could solve the coordination issues by using an omnidirectional wheel. This enabled the robot to align on-the-fly, but without rotating its body. Therefore, the robot can move forward, backward, and sideways at high efficiency, and remain in a stable position without expending any energy. At the same time, the robot can also climb stairs swiftly, when necessary.

For correct operation, the wheg system that the team developed requires a servo motor to be added to each wheel and operated with a simple algorithm. As the design is straightforward and basic, any other team can easily replicate it.

According to the researchers, the system has abundant advantages with very few drawbacks. The team feels it can pose a threat to the legged robots, and any robotic application can adopt this design.

The team has evaluated their OmniWheg robot system on a multitude of real-world indoor scenarios. This includes climbing steps of various heights, circumventing obstacles, and moving/turning omnidirectionally. They found the results to be highly promising, and the wheel-leg robot could successfully navigate the common obstacles quite flexibly and efficiently.

Micro 3D Printing for Miniaturization

Engineers have been using additive manufacturing for prototyping for about 30 years now and are also using it for production. However, the biggest value addition from additive manufacturing comes from producing parts that other traditional manufacturing methods find difficult.

Fabricators use additive manufacturing as a valuable and important solution for producing parts such as those including complex design features like internal geometries and cavities that are impossible to achieve by regular machining. Additive manufacturing is helpful in producing structural elements that are too cumbersome or difficult to generate effectively by conventional means.

At present, engineers use 3D printers for printing large parts quickly. These parts may have resolutions around 50 µm and tolerances around 100 µm. However, sometimes, they also need to produce parts with sub-micron resolutions that are smaller than 5 um. Therefore, they needed a system for printing micro-sized parts at a reasonably high print speed.

Smaller parts require a more precise production process. For instance, cell phones and tablets, microfluidic devices for medical pumps, cardiovascular stents, MEMS, industrial sensors, and edge technology components require connectors with high resolution and accuracy. Most standard additive manufacturing machines cannot provide the resolution necessary for micro-sized parts.

BMF or Boston Micro Fabrication designs and manufactures the PµSL or Projection Micro Stereolithography technology-based printers. Using PµSL printers, it is possible to create 3D printed parts with 2 µm resolution at ±10 um scales. These 3D printers incorporate the benefits of both the SLA or stereolithography technologies and the DLP or digital light processing technologies.

Using a flash of ultraviolet light at microscale resolutions, these PµSL printers cause a rapid photopolymerization of an entire layer of resin. This takes place at ultra-high precision, accuracy, and resolution, not possible to achieve with other technologies.

For faster processing, the PµSL technology supports continuous exposure. Other design elements allow additional benefits to the user. For instance, in printers using the standard SLA technology, the bottom-up build method requires a support structure to hold the part to the base, while also supporting the overhanging structures. Conventional SLA systems can typically achieve resolutions of 50 µm, an overall tolerance of ±100 µm, and a minimum feature size of 150 µm. Similarly, standard DLP systems using a similar bottom-up build structure offer 25-50 µm resolution, an overall tolerance of ±75 µm, and a minimum feature size of 50-100 µm.

On the other hand, the PµSL uses a top-down build, thereby minimizing the need for a support structure. It also provides a way to reduce damage while removing bubbles with a transparent membrane. Comparatively, PµSL systems offer resolution down to 2 µm, dimensional tolerances as high as ±10 µm, and minimum feature sizes of 10 µm.

BMF provides this type of quality by properly employing every system component. This includes the resolution of the optics, controlling the exposure and resulting curing, the precision of mechanical components, and the interaction between parts and required support structures. It also depends on the ability to control tolerances across the build and the overall size of the part. Moreover, working with such diverse micro parts requires choosing the right material characteristics.

Standard Connectors for EV Charging

With EVs or electric vehicles becoming a trend for both individuals and commercial operations, more people are opting for them for commuting to work, school, and moving around the town. While there are tax benefits to using EVs, they also reduce our dependence on fossil fuels. Moreover, with the maturing of battery technologies, EV performance is comparable to those of vehicles with traditional internal combustion engines.

With the increasing number of EVs in use, their fundamental and foremost requirement is charging the battery. This aspect has led to a spurt in the growth of electric vehicle charging stations. Manufacturers of electric vehicles produce a range of vehicles that they base on their specific design specifications. However, charging devices need a uniform design so that any make or model of an electric vehicle can hook up for charging. At present, there are two categories of electric vehicle chargers—Level 1 and Level 2.

Level 1 chargers are available with the vehicle. They have adapters that the user can plug into a standard mains 120-Volt outlet. Manufacturers make these chargers common for use in home charging outlets.

Level 2 chargers are standalone types and separate from electric vehicles. They have adapters to plug into a 240-Volt outlet. These chargers are typically available in offices, parking garages, grocery stations, and other such locations. Homeowners may also purchase Level 2 chargers separately.

To allow any model or make of EV to connect to any Level 2 chargers, it is necessary for both the EV and the charger to use a standard connector. At present, the standard charger connector for Level 2 chargers is the SAR J1772. All the latest electric vehicles using plug-in charging use the standard SAE J1772 plug, while the charger connectors use the standard SAE J1772 adapters. These are also known as J plugs. J1772_201710 is the most current revision for the J plug specifications.

While SAE was originally an acronym for the Society of Automobile Engineers, presently they are known as SAE International. They often come up with recommended practices that the entire automobile industry accepts as standards. With the use of the standard SAE J1772 plugs, a customer purchasing an electric vehicle from any manufacturer can charge it using the same charging connector. Public electric charging stations also use the SAE J1772 chargers, and these are compatible with plugs in most vehicles from different manufacturers.

Each SAE J1772 charger has a standard coupler control system consisting of AC and DC residual current detectors, an off-board AC to DC high power stage, an auxiliary power stage, an isolation monitor unit, a two-way communication system over a single wire, contactors, relays, service and user interface, and an energy metering unit. Charging stations with J1772 connectors use a cable for charging the electric vehicle, and the rating of this cable is EVJE for 300 Volts or EVE for 600 Volts.

The EVJE/EVE cable consists of a thermoplastic elastomer jacket and insulation around a center conductor made of copper. The cable usually has two conductors of 18 AWG wire, one conductor of 10 AWG, and another conductor of 16 AWG.