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New Post has been published on http://engineer.city/advanced-modular-watercooled-resistors/

Advanced modular watercooled resistors

Simone Bruckner discusses how these resistors can be used in the yachting industry

From solar panels to hydro and wind generators, the yacht industry has never been shy to embrace new and innovative technologies. Furthermore, customers of luxury yachts have never been shy in spending a little extra to adopt innovations.

There are three types of luxury yachts. Your typical yacht is between 40 and 100 feet, a megayacht is between 100 and 200 feet, and the granddaddy of them all, the superyacht, is anything over 200 feet. Regardless of the size of the vessel, space, aesthetics and ease of maintenance are common concerns for yacht owners.

Yachts require as lot of power to run on board systems and equipment like air conditioning, fridges, lighting, bow and stern thrusters — you name it. However, just as in the home or the factory, these devices don’t run all day every day. There are usually peak times and low energy consumption periods. This often means generators on yachts will run at only 30% of their full load.

When diesel generators run for prolonged periods at low speeds or loads, carbon build-up and internal glazing can affect the generator. This leads to serious operational problems like decreased reliability and increased running costs.

In addition, these issues set off a chain reaction that will result in the generator belching out smoke. This of course, is not ideal on a luxury yacht. If the problem remains unresolved, the generator will eventually fail to start at all and owners will have to buy a new one.

Vessel owners must maintain their generator properly, by bringing it up to a full load regularly. To help, Cressall is currently conducting research into using our EV2 resistors to maintain and test generators on yachts.

The EV2 can be used as a dummy load resistor, used to replicate a full electrical load on the vessel's generator.

One advantage of using the EV2, is that it will dissipate the energy from the generator as heat into the cooling water. This can be used to heat water for the hot water tank.

Using the EV2 on yachts is beneficial because the resistor is lighter and smaller than some new methods used to maintain generators, which involves switchgear, an inverter, controls and large additional batteries. For example, to store enough reserve power for a yacht application, you would have to use batteries approximately six times bigger than a single EV2. Moreover, in a traditional set-ups when batteries are fully charged and cannot store any more power, you would need a resistor to dissipate the excess energy and protect the generator anyway.

A small footprint is crucial in applications where space is limited and this is always the case even in superyachts.

Similarly, any extra weight means that the yacht engine has to work harder to move the vessel, using more fuel and causing more wear to engine components. Essentially, the moral of the story is that when it comes to yachts, the smaller and lighter the equipment, the better.

Furthermore, the EV2 is perfectly suited to marine applications in which moisture, humidity and salt pose problems to electrical devices not built for such an environment. The resistor has a rugged silicone rubber outer skin, giving the EV2 an ingress protection of IP56. This means that even powerful water jets of water cannot penetrate the device.

Light, water resistant and compact, the EV2 could play a key role in maintaining yacht generators as a complete on board package. It could also be one of the next big innovations the sector adopts.

Simone Bruckner is managing director of Cressall Resistors. 

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New Post has been published on http://engineer.city/stability-safety-and-easy-handling/

Stability, safety and easy handling

The CONTA-CLIP SRK series screw connection terminal system combines all crucial innovations in the field of electric terminal blocks terminals and thereby satisfies even very demanding quality requirements regarding stability, safety and easy handling.

The series includes SRK feed-through terminals and SSL protective earth terminals in single and double level versions as well as SSIK fuse disconnect terminals. A very versatile range of accessories is available for all terminal types.

The feed-through standard models are available for a wide range of cross sections between 0,2 mm² to 120 mm², the corresponding earth terminals between 0,2 to 70 mm². Terminal sizes for diameters up to 10 mm² are identical, which allows for the use of uniform cover and partition plates. This also applies to the space-saving double level versions of SRKD and SSLD feed-through and protective earth terminals, which are available for wire cross sections between 0.2 mm² and 10 mm² and with 2×2 or 1×4 connections.

The SSIK fuse disconnect terminal with screw connection system features a hinged disconnect lever that locks in its end position and accommodates a spare fuse. They are available as SSIK 4 models for microfuse types 5 x 20, 5 x 25, 5 x 30 and as SSIK 6 models for fuse types 6.3 x 25 and 6.3 x 32 can be optionally equipped with an LED status display.

A large wire entry bay ensures a quick insertion of solid and flexible wires with or without wire-end ferrules in all terminals. Since rated cross sections are specified for the connection of flexible wires with wire-end ferrules, solid conductors without sleeves of the next largest cross section can be contacted as well.

Due to the clamping yoke system, a high contact force and contact reliability with a low contact resistance are ensured: it indirectly pulls the wire onto the bus bar over the screw and the clamping yoke, which is electrogalvanised, thick-layer passivated and made from hardened steel.

In addition, the screws are captive and the optimised foot construction guarantees a flawless snap-on function and shock- and vibration-resistant hold on mounting rail types TS 35 x 7.5 and TS 35 x 15.

To ensure a maximum of mechanical and electrical safety, the earth terminals have a PE foot contact on both sides and can be snapped onto the rails with no need for screws.

All metal parts, ie screws, clamping yokes, bus bars and PE feet, are securely integrated into the torsion resistant housing. Made from PA 6.6 V0 polyamide, the insulation housings are self-extinguishing, contain no harmful substances and withstand temperatures between -40°C and +120°C. Insulation housings of the SSIK fuse disconnect terminals made from glass-fibre reinforced polyamide withstand an even wider temperature range from -40°C to +140°C.

Standard SRK feed-through terminals for wire cross sections between 2.5 mm² and 10 mm² and SSIK fuse disconnect terminals are equipped with a double cross connection channel. Due to this feature, the potentials can be horizontally distributed in a row of terminals with the help of an SQI cross connector.

Designed for rated voltage/rated current loads, connectors are available with 2 to 10 poles and with 30 poles. A straightedge inside the insulated housing of 30-pole versions allows users to count out poles more easily. For skip bridging, individual contact elements can be easily removed. Cross connections can be cut shorter as required, touch safety of the cut uninsulated side is then re-established with the SQIK insulator cap.

For an easy and permanent labelling of terminals, the identification systems PMC SB, PMC BSTR and MC are available. To attach markers, standard terminals are equipped with up to four marker bars. The extensive accessory range includes rails, mechanical mounting parts and end supports, group marker holders, end plates and covers.

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New Post has been published on http://engineer.city/screw-connection-stability-safety-and-easy-handling/

Screw connection: stability, safety and easy handling

The CONTA-CLIP SRK series screw connection terminal system combines all crucial innovations in the field of electric terminal blocks terminals and thereby satisfies even very demanding quality requirements regarding stability, safety and easy handling.

The series includes SRK feed-through terminals and SSL protective earth terminals in single and double level versions as well as SSIK fuse disconnect terminals. A very versatile range of accessories is available for all terminal types.

The feed-through standard models are available for a wide range of cross sections between 0,2 mm² to 120 mm², the corresponding earth terminals between 0,2 to 70 mm². Terminal sizes for diameters up to 10 mm² are identical, which allows for the use of uniform cover and partition plates. This also applies to the space-saving double level versions of SRKD and SSLD feed-through and protective earth terminals, which are available for wire cross sections between 0.2 mm² and 10 mm² and with 2×2 or 1×4 connections.

The SSIK fuse disconnect terminal with screw connection system features a hinged disconnect lever that locks in its end position and accommodates a spare fuse. They are available as SSIK 4 models for microfuse types 5 x 20, 5 x 25, 5 x 30 and as SSIK 6 models for fuse types 6.3 x 25 and 6.3 x 32 can be optionally equipped with an LED status display.

A large wire entry bay ensures a quick insertion of solid and flexible wires with or without wire-end ferrules in all terminals. Since rated cross sections are specified for the connection of flexible wires with wire-end ferrules, solid conductors without sleeves of the next largest cross section can be contacted as well.

Due to the clamping yoke system, a high contact force and contact reliability with a low contact resistance are ensured: it indirectly pulls the wire onto the bus bar over the screw and the clamping yoke, which is electrogalvanised, thick-layer passivated and made from hardened steel.

In addition, the screws are captive and the optimised foot construction guarantees a flawless snap-on function and shock- and vibration-resistant hold on mounting rail types TS 35 x 7.5 and TS 35 x 15.

To ensure a maximum of mechanical and electrical safety, the earth terminals have a PE foot contact on both sides and can be snapped onto the rails with no need for screws.

All metal parts, ie screws, clamping yokes, bus bars and PE feet, are securely integrated into the torsion resistant housing. Made from PA 6.6 V0 polyamide, the insulation housings are self-extinguishing, contain no harmful substances and withstand temperatures between -40°C and +120°C. Insulation housings of the SSIK fuse disconnect terminals made from glass-fibre reinforced polyamide withstand an even wider temperature range from -40°C to +140°C.

Standard SRK feed-through terminals for wire cross sections between 2.5 mm² and 10 mm² and SSIK fuse disconnect terminals are equipped with a double cross connection channel. Due to this feature, the potentials can be horizontally distributed in a row of terminals with the help of an SQI cross connector.

Designed for rated voltage/rated current loads, connectors are available with 2 to 10 poles and with 30 poles. A straightedge inside the insulated housing of 30-pole versions allows users to count out poles more easily. For skip bridging, individual contact elements can be easily removed. Cross connections can be cut shorter as required, touch safety of the cut uninsulated side is then re-established with the SQIK insulator cap.

For an easy and permanent labelling of terminals, the identification systems PMC SB, PMC BSTR and MC are available. To attach markers, standard terminals are equipped with up to four marker bars. The extensive accessory range includes rails, mechanical mounting parts and end supports, group marker holders, end plates and covers.

Images: 

New Post has been published on http://engineer.city/why-it-makes-sense-to-add-a-ground-choke/

Why it makes sense to add a ground choke

Herbert Blum presents a simple and safe solution for ground connection interferences

Switched mode circuits are increasingly being used in electronic devices. Due to their rapid switching speeds, the probability of high-frequency ground connection interferences is also becoming more prevalent. A correctly specified and placed ground choke offers a simple and safe solution.

Today, electric motors are required to operate within an optimal RPM range and, for that reason, are equipped with frequency inverters. LED lights with switch mode power supplies are replacing incandescent bulbs. These are just two examples that showcase the current trend for increased efficiency and better controllability through the use of switched mode controls.

Regardless of the positive benefits in terms of increased efficiency, these circuits can also lead to increased interferences, which often went unaddressed, although they are now becoming more relevant.

The topic of overlooked interferences concerns that of high-frequency interferences on the ground as well. The ground receives little attention (compared to interferences generated on the line) during the EMC-compliant design of electronic devices. Yet this can quickly change if a ground loop develops.

When ground loops occur

Ground loops develop due to the different impedances of various ground connections from one or more devices. Although all ground connections have the same potential for the 50Hz load current, they can have different potentials due to the different line impedances for the high-frequency interferences. As a result, switched mode circuits have high frequency currents that can be transferred by the capacitive coupling or via interference suppression capacitors to the ground. There is usually no problem if the ground is good or there is only one ground connection; these currents are conducted to the ground. But, if there are different potentials from two or more ground connections, this can produce high-frequency currents.

The effects of the equalising currents on the ground can be drastic: for example, the interferences may damage the electronic control of the device. It is also conceivable that this can result in failure to meet EMC specifications, even though a suitable filter was installed in the device.

What’s the solution?

Adding a ground choke can solve this problem. The ground choke, however, must be correctly specified for it to also satisfy strict safety regulations, with regard to conductor cross-section and resistance. Furthermore, the ground choke must be installed so that possible high-frequency interference currents on the ground cannot circumvent the choke via the housing. This is particularly a concern with in-line filters. These filters are screwed directly to the metal housing for optimal performance. By screwing the filter casing directly to the grounded metal housing, low impedance is achieved, which thereby improves the interference suppression capacitor’s damping properties to ground. Device inlet filters or installed filters that are connected this way, to the mounting flange on the metal housing, are thus connected directly to ground. In addition, they also have a ground connection that is connected via a cable to the housing. If a ground choke is now integrated into the ground cable after the filter, the interference currents can bypass the choke via the metal housing of the device and the filter housing.

Schurter offers a simple and safe solution to solving ground loop interference, with the KFA power entry module, which integrates a ground choke. In addition to the current compensated choke on the polar and neutral conductors, the mains filter has another linear choke on the ground conductor. This ground choke isolates the metal housing and the ground connection of the device from the mains ground. This solution effectively breaks any possible ground loops. The KFA power entry module with 1- or 2-pole fuse holder and filter is available in a wide range of versions and models. The filter with the ground choke also meets current safety requirements.

For more information, visit wwe.engineerlive.com/ede

Herbert Blum is with Schurter. 

  SCHURTER_shutterstock.jpg

Caption: Example of wired device 

  Left diagram.pdf

Right diagram.pdf

Gill: if these PDFs are usable images then they need to go in that order (left and right)

  Caption for Left diagram.pdf: Incorrect installation: ground currents bypass the ground choke

   Caption for Right diagram.pdf: Correct installation: filter with integrated ground choke

  SCHURTER_KFA.TIF

Caption: Device inlet filters with Schurter’s integrated KFA ground choke

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New Post has been published on http://engineer.city/configurable-low-power-embedded-controllers/

Configurable low-power embedded controllers

Microchip announces the MEC14XX family of highly configurable low-power embedded controllers customised to the needs of x86-based notebook and tablet platform designers.

The scalable family of MEC14XX devices is one of the first to support both the Intel Corporation’s new Enhanced Serial Peripheral Interface (eSPI) and the existing Low Pin Count interface (LPC).

To ease the mobile computing industry’s transition to the new interface and lower-voltage designs, Microchip’s MEC14XX family also provides a flexible arrangement that allows multiple I/O signals to be configured to support either 3.3V or 1.8V, reducing the system bill-of-materials cost by eliminating the need for external voltage translators.

These features of the MEC14XX family also allow for a seamless migration of intellectual property (IP) reuse across multiple x86 computing platform architectures, such as Intel Atom, Intel iCore and AMD-based systems.  This is also Microchip’s first embedded controller family targeted for general x86 computing that includes Microchip’s award-winning MPLAB development tool support.

The MEC14XX devices are offered with a choice of 128 KB, 160 KB or 192 KB of closely-coupled SRAM for code and data that loads from SPI-flash.  Designers can leverage the host SPI-flash (used for BIOS storage) for non-volatile EC firmware storage, as a cost-effective system solution. The added choice of either the MEC140X LPC interface devices or the MEC1418, which supports both the LPC and eSPI interfaces, allows the designer to select the most cost-effective device for a particular platform and provides manufacturers the ability to preserve their investments as the industry transitions.  All members of the Microchip MEC14XX family are pin and register compatible.

Each member of the MEC14XX family is based on Microchip’s 32-bit PIC MCU architecture and is supported by Microchip’s development tools.

The MEC1404 (128 KB SRAM) and MEC1408 (192 KB SRAM) embedded controllers supporting the Intel LPC interface are available today for sampling and volume production.  The MEC1418 (192 KB SRAM) embedded controller, supporting both the Intel LPC and eSPI interfaces, is available today for sampling and volume production. All MEC14XX devices are currently offered in a 128-VTQFP package.

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New Post has been published on http://engineer.city/configurable-low-power-embedded-controllers/

Configurable low-power embedded controllers

Microchip announces the MEC14XX family of highly configurable low-power embedded controllers customised to the needs of x86-based notebook and tablet platform designers.

The scalable family of MEC14XX devices is one of the first to support both the Intel Corporation’s new Enhanced Serial Peripheral Interface (eSPI) and the existing Low Pin Count interface (LPC).

To ease the mobile computing industry’s transition to the new interface and lower-voltage designs, Microchip’s MEC14XX family also provides a flexible arrangement that allows multiple I/O signals to be configured to support either 3.3V or 1.8V, reducing the system bill-of-materials cost by eliminating the need for external voltage translators.

These features of the MEC14XX family also allow for a seamless migration of intellectual property (IP) reuse across multiple x86 computing platform architectures, such as Intel Atom, Intel iCore and AMD-based systems.  This is also Microchip’s first embedded controller family targeted for general x86 computing that includes Microchip’s award-winning MPLAB development tool support.

The MEC14XX devices are offered with a choice of 128 KB, 160 KB or 192 KB of closely-coupled SRAM for code and data that loads from SPI-flash.  Designers can leverage the host SPI-flash (used for BIOS storage) for non-volatile EC firmware storage, as a cost-effective system solution. The added choice of either the MEC140X LPC interface devices or the MEC1418, which supports both the LPC and eSPI interfaces, allows the designer to select the most cost-effective device for a particular platform and provides manufacturers the ability to preserve their investments as the industry transitions.  All members of the Microchip MEC14XX family are pin and register compatible.

Each member of the MEC14XX family is based on Microchip’s 32-bit PIC MCU architecture and is supported by Microchip’s development tools.

The MEC1404 (128 KB SRAM) and MEC1408 (192 KB SRAM) embedded controllers supporting the Intel LPC interface are available today for sampling and volume production.  The MEC1418 (192 KB SRAM) embedded controller, supporting both the Intel LPC and eSPI interfaces, is available today for sampling and volume production. All MEC14XX devices are currently offered in a 128-VTQFP package.

Images: 

New Post has been published on http://engineer.city/sealed-connector-system-for-automotive-applications/

Sealed connector system for automotive applications

Molex now offers its MXP120 Sealed Connector System for both safety and non-safety electronics applications. For non-safety powertrain and body electronics applications, the MXP120 Sealed Connector System is available in black outer housings, while for safety applications the connectors and receptacles have distinctive yellow outer housings.

The 4.00mm pitch, 1.20mm MXP120 Sealed Connector System offers superior mating, sealing and performance for severe applications. In addition to 1-by-3, 1-by-4 and 1-by-6 circuit sizes, the connection system includes a small 1-by-2 version that meets USCAR-25 ergonomic requirements, especially versus the CPA push surface. Automotive and commercial vehicle manufacturers can use MXP120 devices to replace 1.50mm terminal connections in space-constrained applications.

MXP120 sealed connectors and receptacles have several other key benefits, including:

* A single-wire-seal (SWS) connection system with a robust perimeter seal that is IPX8 rated and withstands high-pressure spray environments (IPX9K) under certain conditions.

* Compatibility with AK and USCAR interfaces.

* A design that uses the worldwide AK cavity definition, which confirms global acceptance and marketability.

* Ability to meet power requirements up to 13.0A.

Key safety applications for MXP120 yellow connector systems include supplemental inflatable restraints (SIR), safety restraint systems (SRS), seat-belt pretensioners and steering-wheel, side and curtain airbags. Applications for MXP120 black connector systems include body electronics connections in wet areas, such as exterior lighting, turn signal indicators and door-lock mechanisms. Black connectors can be also used in severe powertrain applications that include fuel injection systems, emission controls and ignition coils.

MXP120 Sealed Connector Systems are not restricted to automotive and are also suitable for many industrial and consumer applications where sealing is required and package size is a constraint.

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New Post has been published on http://engineer.city/turning-clothing-into-information-displays/

Turning clothing into information displays

Researchers from Holst Centre (set up by TNO and imec), imec and CMST, imec’s associated lab at Ghent University, have demonstrated the world’s first stretchable and conformable thin-film transistor (TFT) driven LED display laminated into textiles. This paves the way to wearable displays in clothing providing users with feedback.

Wearable devices such as healthcare monitors and activity trackers are now a part of everyday life for many people. Today’s wearables are separate devices that users must remember to wear. The next step forward will be to integrate these devices into our clothing. Doing so will make wearable devices less obtrusive and more comfortable, encouraging people to use them more regularly and, hence, increasing the quality of data collected. A key step towards realising wearable devices in clothing is creating displays that can be integrated into textiles to allow interaction with the wearer.

“Wearable devices allow people to monitor their fitness and health so they can live full and active lives for longer. But to maximise the benefits wearables can offer, they need to be able to provide feedback on what users are doing as well as measuring it. By combining imec’s patented stretch technology with our expertise in active-matrix backplanes and integrating electronics into fabrics, we’ve taken a giant step towards that possibility,” says Edsger Smits, Senior research scientist at Holst Centre.

The conformable display is very thin and mechanically stretchable. A fine-grain version of the proven meander interconnect technology was developed by the CMST lab at Ghent University and Holst Centre to link standard (rigid) LEDs into a flexible and stretchable display. The LED displays are fabricated on a polyimide substrate and encapsulated in rubber, allowing the displays to be laminated in to textiles that can be washed. Importantly, the technology uses fabrication steps that are known to the manufacturing industry, enabling rapid industrialization.

Following an initial demonstration at the Society for Information Display’s Display Week in San Jose, USA earlier this year, Holst Centre has presented the next generation of the display at the International Meeting on Information Display (IMID) in Daegu, Korea, 18-21 August 2015. Smaller LEDs are now mounted on an amorphous indium-gallium-zinc oxide (a-IGZO) TFT backplane that employs a two-transistor and one capacitor (2T-1C) pixel engine to drive the LEDs. These second-generation displays offer higher pitch and increased, average brightness. The presentation will feature a 32×32 pixel demonstrator with a resolution of 13 pixels per inch (ppi) and average brightness above 200 candelas per square meter (cd/m2). Work is ongoing to further industrialise this technology.

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