What is a Resolver?
A resolver is a rotary transformer consisting of a sensor that is used to accurately measure a rotor’s angular position relative to the stator, as well as speed of rotation. It has no electronic parts, which makes it suitable for long-term use in harsh and demanding environments including those with high temperatures, vibrations, radiation and residue, for example heavy industrial motors, servo motors, and automobiles. The digital version of a resolver is a rotary encoder.

Photo: Dynapar.com
https://ecatalog.dynapar.com/ecatalog/resolvers/en?_ga=2.112395652.1441738319.1562699952-819002326.1562699952 （Search date: 2019/7/10）

How are Resolvers Used?

A resolver is used as a feedback device to ensure that a rotor will rotate properly, and by extension, the motor will accelerate, slow down, or stop at precise moments.  Manufacturers using robotic equipment depend on reliable servo motors to control arm movement while it operates at optimal speeds, making both safety and efficiency high priorities.

Resolvers are also a critical part of a motor on hybrid or electric vehicles to serve as the rotor position sensor.  In order for the car’s AC synchronous motor setup to function properly, the computer needs to know the position of the rotor at any given time so that the appropriate stator winding is charged with the proper phase current from the inverter – a resolver is essentially a sensor that helps to do that.

The Memory HiCorder as a Resolver Digital Converter

During motor development, a multi-channel Memory HiCorder MR6000 can be used as a resolver digital converter to evaluate the rotor position and the rotational speed based on the signal waveforms.  The ability to capture the resolver’s excitation signal (reference voltage signal) and two output signals (sine and cosine voltage) with a single analog unit, and then using another channel to make calculations for the rotation angle, makes it a turnkey solution for this application.  The Memory HiCorder’s high 16-bit resolution enables customers to capture the slight changes in the output waveforms that serves as valuable information for advancing the precision of the resolver’s position sensing during development.

How to Set Up and Measure? 

• Input the resolver’s excitation signal and output signal to the 4ch Analog Unit U8978 (range: 100mVf.s. to 40Vf.s.)
• The remaining input slots of the MR6000 can be fitted with other modules to let you measure temperature, control signals, torque, and current signals at the same time in order to evaluate the effect of other factors on the signal as well as measure additional physical properties of a motor, especially EV motors that require highly efficient but precise control.
• Use the built-in waveform calculation function to calculate the resolver’s angle of rotation and display on the screen

Products Used:

・ Memory HiCorder MR6000

・ 4ch Analog Unit U8978, or 4ch Analog Unit U8975, depending on voltage specificaDons of resolver

*Please contact your Hioki sales office for more informa5on about how to configure the instrument.

HIOKI is pleased to announce the launch of the Current Probe CT6710 and CT6711. Both products provide three ranges (30 A, 5 A, and 0.5 A) to facilitate observation of waveforms representing currents as large as 30 A or as small as several hundred microamperes. This capability makes the probes ideal for observing current waveforms under a variety of operating conditions, including inrush currents*¹, micro currents, and high-speed currents*².

■ DEVELOPMENT BACKGROUND

Current probes convert the current flowing through a wire into a voltage signal.  They are connected to data acquisition equipment such as oscilloscopes and Hioki Memory HiCorders so that those devices can display the current waveform, and are used principally in the development and design of products such as electrical and electronic devices, industrial equipment, and electronic components.

In recent years, manufacturers in every industrial sector have redoubled their efforts to save energy, for example by increasing energy efficiency and by lowering power consumption. This renewed focus has made it necessary for engineers involved in device and component R&D to observe abrupt changes in currents, rapid variations in operating currents, and micro currents, creating demand for probes with broader current and frequency coverage.

Since launching its first clamp-on tester in 1971, HIOKI has developed numerous current sensors for use in a variety of applications. In 2014, the company sought to meet customer demand for high sensitivity by introducing a pair of current probes (the CT6700/CT6701) with 10 times the sensitivity of the legacy models (the 3273/3276). However, the new devices’ current-measuring capabilities were limited by its single range (5 A) configuration even as demand for a single probe capable of measuring both micro and large currents grew. To meet this demand, HIOKI sought to develop a current probe with a wide frequency band (DC to 120 MHz) and a broad measurement range (0.5 A to 30 A).

■ FEATURES
1. Observe waveforms from 30 A to micro currents thanks to 3 ranges (30 A, 5 A, and 0.5 A)
Existing current probes such as the Hioki CT6700 and CT6701 offer a single, 5 A range. The new CT6710 and CT6711 provides three ranges (30 A, 5 A, and 0.5 A) so that users can observe a wide range of current waveforms with one device. The result is an instrument capable of accurately identifying currents under various operating conditions, for example by using the 0.5 A range to measure micro currents and the 30 A range to measure inrush currents.  In addition, the range can be switched simply by pressing a button on the probe’s relay box.

 2. Observe current waveforms across a wide frequency band

The CT6710 and CT6711 can observe current waveforms across a wide frequency band, from DC to megahertz bandwidths. With a band of either DC to 50 MHz (CT6710) or DC to 120 MHz (CT6711), the probes accommodate use in an array of settings.

3. Ten times the sensitivity of existing and comparable probes, enabling micro currents on the order of several hundred microamperes to be observed clearly

Because they offer higher sensitivity than existing devices, the CT6710 and CT6711 can observe micro currents with a high degree of clarity.  The output rate of 1 V/A on the sister products, CT6701 and CT6700, as well as competitive devices means that they generate an output voltage of 1 V for a current value of 1 A.  At this low output rate, users need to set the oscilloscope to a high-sensitivity range where noise is more pronounced, resulting in the inability to precisely identify micro currents that are hidden by the  noise. By contrast, the CT6710 and CT6711 deliver an output rate of 10 V/A when using the 0.5 A range, giving them 10 times the sensitivity of prior Hioki probes.  The higher output rate enables users to make measurements at the low-sensitivity range where noise is less noticeable.   Additionally, overall improvements in the probes’ S/N ratio*³ allow use of oscilloscope functionality*⁴ to observe micro current waveforms with a high degree of clarity.

4. One-touch BNC connectors

Connect the CT6710 or CT6711 to an oscilloscope or Memory HiCorder simply by inserting its connector straight into the host instrument’s BNC connector, eliminating the need to rotate to tighten. Additionally, the connector is locked in place automatically so that there’s no need to worry about the sensor accidentally detaching. One-touch disengagement of the locking mechanism makes it easy to disconnect the probe.

■ PRINCIPAL MARKETS

• Development and design of electrical and electronic devices, industrial devices, electronic components, mobile devices, etc.
• Development and design of automobiles, transport equipment, and motors
• Fundamental research at universities, research institutes, etc.

■ LINEUP

CURRENT PROBE CT6710 (DC to 50 MHz)

CURRENT PROBE CT6711 (DC to 120 MHz)

Note: Use the optional Power Supply 3269 to drive the current probe when power from the Memory HiCorder or oscilloscope is not available.

POWER SUPPLY 3269  (designed to accommodate up to two probes)

Download the product catalog here: Current Probe CT6710 and CT6711

*1 Inrush current: A large current that flows momentarily when power is first supplied to an electrical device.

*2 High-speed current: A current that rises or falls abruptly. Some devices need to be able to cycle current on and off quickly in order to improve energy efficiency.

*3 S/N ratio: The ratio of a signal to the amount of noise. The higher the S/N ratio, the less the noise, allowing high-quality signal measurement.

*4: Oscilloscope averaging function or band-limiting function. 

Hioki is pleased to announce the launch of the Electrode Resistance Measurement System RM2610.

The RM2610 isolates and quantifies the resistance characteristics of electrode sheets, a major component of lithium-ion batteries (LIBs), as two components: the composite layer resistance and the interface resistance between the composite layer and collector.  The system allows users to visualize these two quantities by measuring the surface of the electrode sheet with a test fixture that consists of an array of test probes and then using proprietary analytical techniques to quantify them. By quantifying resistance characteristics that have been impossible to visualize in the past, the RM2610 assesses electrode sheet characteristics and quality trends and to help LIB developers visualize how resistance characteristics vary in response to changes in composite materials and composition. In this way, it facilitates improvements in the quality and development of lithium-ion batteries.

Electrode Sheet Diagram

DEVELOPMENT BACKGROUND

Lithium-ion batteries are rechargeable batteries in which the movement of lithium ions between positive and negative electrodes causes the battery to charge or discharge. This type of battery has entered into widespread use in compact devices such as smartphones and computers because it delivers high capacity in a lightweight package. Mass-production of lithium-ion batteries on a global scale is growing rapidly in the wake of efforts to evolve, improve, and develop them for use as rechargeable batteries in electric vehicles (EVs) as the world moves toward a carbonless society.

Electrode sheets are made by coating a collector (the part that attracts electricity; typically with a positive electrode made of aluminium and a negative electrode made of copper) with a liquid (the composite) containing ingredients such as an active substance (which serves to capture and release lithium ions) and a conductive auxiliary agent (which serves to facilitate electron conductivity). The sheets are used as electrodes in lithium-ion batteries. Since lower internal resistance means higher performance in terms of output and service life, it is extremely important to observe the resistance characteristics of electrode sheets, which are as a major component of lithium-ion batteries.

However, until now it has been impossible to evaluate electrode sheets until the lithium-ion battery they’re used in is fully assembled, making it necessary to spend a significant amount of time and effort creating prototypes. Complicating the issue is the fact that it has not been possible to measure the overall resistance characteristics of electrode sheets using traditional measurement techniques (measurement of pass-through resistance and 4-wire volume resistivity measurement), leaving no means of assessing the resistance of the composite layer or of the interface (plane of contact) between the composite layer and collector. Accurate knowledge of these characteristics not only makes possible the fine-grained observation of which materials, compositions, and manufacturing conditions yield improved performance, but also their evaluation at the electrode sheet stage of the battery manufacturing process. These capabilities promise to drive significant improvement in LIB quality and development efficiency.

Hioki focused on the issues described above and utilized proprietary analytical techniques to engineer the RM2610 so that it could quantify the interface resistance between the composite layer and collector, which has been impossible to visualize until now.

■ Electrode Resistance Measurement System RM2610: System components

・Press Unit RM9003

・Test Fixture RM9004

・Connection Cable RM9005

・Electrode Resistance Meter RM2611

・Resistance Calculation Software RM2612

■ PRINCIPAL MARKETS

・Lithium-ion battery manufacturers and venture companies

・Manufacturers of materials used in lithium-ion batteries

Download Product Catalogue Here : RM2610

More than 50 people from all walks of life, joined Hioki Singapore Pte. Ltd. on 16th June 2019 to plant a total of 305 trees in Ban Naka Community Forest, Ratchaburi, Thailand. Among the group includes Hioki distributors from Thailand, Hioki associates from Japan, Singapore, Malaysia, Thailand, Vietnam & Indonesia, students from Baan Lankha school and villagers from Ban Naka Community forest.

In addition to tree planting, the group had also built and repaired 3 weirs. Weirs are commonly used to prevent flooding, and to measure water discharge. It is also used to serve as a water catchment tool in case of drought season to ensure the forest and community maintain important source of water.

Aside from business growth, Hioki E.E Corporation emphasizes on social and environmental balance by following closely to the company’s corporate philosophies, “Contribution to Society” & “Respect for Humanity”. Hioki Tree Planting 2019 (previously known as Green Point Campaign) is the fifth instalment of the annual initiative by Hioki Singapore Pte. Ltd., to plant trees on behalf of HIOKI users to a tree-planting organization when the customers purchase a qualifying product.

“It is really wonderful and important for Hioki to recreate good environment through activity like this, together with children who bear the future on Earth.” said Mr. Kazutoshi Hosoya, President & CEO, Hioki E.E Corporation. 

“And this time, our Thailand distributors also join us for this activity, I really appreciate that. I am also very glad that many students and villagers representing the local communities are able to join us as well.” Mr Toshihiko Tsuchiya, Managing Director of Hioki Singapore Pte. Ltd. added. 

The group planted a total of 305 trees, consisting of Syzygium cumini, Lagerstroemia speciose and eucalyptus.

About the area – Ban Naka Community Forest

Ban Naka Community forest is located at National forest Yanghak sub-district, Paktho district, Ratchaburi province, with an approximate area of 1,135 acre with high forest & mixed forest vegetation. The community work closely together to protect the forest as it helps to keep the climate stable, absorbing carbon dioxide and releasing oxygen, and they regulate the water supply and improves its quality. The people living around the forests depend on them for fuel, food, medicines and building materials.Ban Naka Community Forest is the winner of the provincial award “People protect forest, the forest love the community” in 2013.

Hioki associates, distributors, students and villagers from local community worked together to repair  3 wiers which are important protect the surrounding environment in case of flood

The team comes together to plant a total 305 trees in Ban Naka community forest

Click to watch Hioki Singapore Tree Planting 2019 Video Highlights!

Power Quality Analyser PQ3198 

Hioki has launched the Power Quality Analyzer PQ3198, a new instrument that revamps the functionality and specifications of its predecessor, the Power Quality PW3198. The product  makes it even easier to record and analyse power supply issues, including by eliminating the need for a dedicated sensor power supply and by enabling power and efficiency measurement of 2 circuits.

Leading industry magazine Industrial Automation Asia had recently interviewed Ken Sakai, Senior Research Engineer of Hioki E.E Corporation, who had told us more about the company’s latest innovation, Power Quality Analyzer PQ3198. Below are his replies.

 Highlights of the PQ3198… 

When there are many events to record, making settings can be very challenging using typical power analyzers.  The PQ3198’s PRESET feature lets you make the basic power analysis measurement settings easily because the instrument automatically configures event threshold settings based on generally accepted standards or practices.  Customers can choose from 5 different “courses” depending on the issue they are facing, and the PQA will make the appropriate settings to provide the proper analytical data.

Also, if you use the high harmonic event detection function, if a harmonic exceeding 3kHz appears on your line, you can record the waveform and conduct additional frequency analysis on a PC with our free software, PQ ONE.  This lets you discover the cause of harmonic problems in a more convenient way.

The differences between the legendary product PW3198 & PQ3198… 

The biggest difference and advantage provided by the new PQ3198 is the ability to power current sensors directly from the unit rather than using a separate AC power supply.  Another major improvement is the ability to record 9,999 events, versus only 1000 events with the earlier product.  This helps prevent the recording from stopping when 1000 events are reached.

Another big difference is the ability to calculate efficiency using the power measurement values from Channel 4.  This in effect makes the PQA a simplified inverter efficiency measurement device for simple testing of inverters.  For more precise and advanced testing, of course we recommend our flagship power analyzer PW6001 or PW3390.

Another addition to the PQ3198 is the FTP server function that will enable customers to download their data from remote locations easily.

Challenges faced in developing PQ3198 and possibility of an improvised version… 

The legacy PW3198 and its predecessor were very successful products, so we wanted to maintain the same ease of use and functionality with the new PQ3198, while providing greater value in terms convenience and meeting real application needs.  The challenge was identifying what they were, and we concluded that the ability to record more events and streamlining the entire measurement system by removing the use of additional power supplies to drive the current sensors were the most important improvements that we should be providing to our customers.  Going forward, we will continue to closely monitor for changes in applications, as well as to international power quality measurement standards so that our PQA is always compliant.

The applications of PQ3198 in EV car and others…

Thanks to isolation between Channels 1/2/3 and Channel 4, customers can safely measure the primary and secondary sides of an inverter at the same time without fear of short-circuits stemming from the connection of lines with different electrical potentials.  In addition, customers can use Channel 4 to measure power or efficiency.  This capability opens up opportunities for applications involving the inspection of the power quality of EV rapid charging stations to evaluate power conversion efficiency.  The PQ3198 can measure the current and power of equipment operating at a fundamental frequency of 40 to 70Hz, and maximum carrier frequency of 20kHz, with performance that is almost equivalent to the more advanced Hioki Power Analyzers PW3390 or PW6001.

The biggest and most important application is, of course, troubleshooting power quality issues, especially when the cause is unknown.  With the variety of event settings and number of recordable events, customers using the PQ3198 will have a very easy and effective tool to resolve power quality issues.

Your development goals for the Power Quality Analyzer PQ3198… 

Our goal is for the Power Quality Analyzer to be used by as many customers as possible from around the world so that we can contribute to improving the quality of electricity at customer sites, and by extension, save our customers time and money by increasing productivity and yield.

Regular maintenance and management are essential in order to keep electrical equipment operating properly in buildings and manufacturing plants.  Clamp meters make it easy to measure current simply by clamping the jaws of the instrument around the cable being measured, and as a result they have entered into wide use in maintenance management applications. Distribution panels have been shrinking in recent years, with the result that the wires inside them are packed closer together. Less space between adjacent cables makes it harder for technicians to do their jobs.

The CM4376 AC/DC Clamp Meter, which is designed to be more easily clamped around wires, has the thinnest sensor in the industry at 9.5 mm, allowing it to be applied to wires that are surrounded by just 13 mm of space. This capability makes it possible to measure currents at a point directly underneath circuit breakers—a task that was impossible with its predecessor—and significantly boosts work efficiency when making such measurements. Additionally, the sensor can be paired with GENNECT Cross, a free smartphone app whose waveform display and logging functionality boost convenience by allowing users to visualize current.

At the fair’s product competition, the CM4376 was praised by measurement professionals for delivering improved performance, work safety, and peace of mind.

Hioki will take encouragement from this accolade as it continues to provide unique products from the customer’s perspective.

■JECA FAIR （Japan Electrical Construction Association）
The JECA Fair, which is hosted by the Japan Electrical Construction Association and sponsored by entities including the Ministry of Land, Infrastructure, Transport and Tourism; the Ministry of Economy, Trade and Industry; and the Ministry of the Environment, is the largest electrical equipment tradeshow held in Japan. The event, which  brought together people from throughout the industry for the 67th time in 2019, alternates between Tokyo and Osaka.

The CM4376 is the 9th Hioki product to be recognized at the JECA Fair since the 44th fair in 1996.

Importance of Maintaining the Proper Operation of Uninterruptible Power Supplies (UPS)

What Signal Do You Measure?

How Do You Measure the UPS?

Conventional Approach vs. using a PQA

Note: Voltage Swells and Dips Can Stress UPS

Related Product:
PQ3198 Power Quality Analyzer