Electro-ramblings

OhmArt Cartoon: A dangerous surge is on the loose!

2012-02-10T08:32:21Z

It's time for another in our series of posts featuring the excellent electronics cartoons from OhmArt! Check out more on Barney's blog, too...

At the top of the hour, on Network News, is a story to worry all watching Transistors!

Can you find what you're looking for on ElectronicsWeekly.com?

2012-02-09T14:20:19Z

Take part in our survey >>

A call for action and help! We are currently reviewing our website to find out how we can best improve the user experience.

One area that has come out of our research in the past is regarding how people navigate around the site and find information, so we would like your help in making sure we are organising the content in the best way possible.

Here a link to an online survey which asks you to organise a list of content items into groups that belong together. There are no right or wrong answers, it's simply about what makes sense to you.

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The survey is anonymous and should only take about 10 minutes to complete. Your feedback will help us in continuing to deliver the best website we can for you.

Thanks in advance for your time!

An Engineer in Wonderland - Help Alice with assembler code

2012-02-09T11:45:57Z

I am trying to write some code for a microcontroller - a PIC - and have stumbled across a problem, and a sort-of answer.

As I have no formal training in well-structured assembler code, I suspect my answer is sub-optimal - or even sub-passable - and could do with some help.

My hope is that some kind soul will say 'What you need is to use Shubunkin's inferior parameter pass, or the Smyth-Hamilton's data swap', or some such.

Anyway, this is the problem:

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The main loop transfers this number to a working register to use it, then clears John.

The problem that I envisage is: That the ISR will very occasionally put a new value into John in the 1µs between the main loop reading John and the main loop clearing John.

Which will mean the main loop occasionally misses a new value from the ISR.

How do you get over that?

My clunky answer is to have the ISR read John to make sure it is clear before storing a new value into it. If John is not clear, the ISR will have to store the spare value until the next time tick and have another go at putting it into John.

The additional time delay will be no problem, but the ISR may have to store one or two spare values pending putting them into John.

And is there a book on good structured assembler programming that would help?

'Alice'

Please don't respond below as our spam blocking system doesn't work and the inbox is overwhelmed by all kinds of generous offers from a multitude of rather annoying people.

Should you feel the need, respond to alice@electronicsweekly.com with 'Assembler' in the title.

No email addresses are collected for marketing (or any other) purposes from responses to this blog. I will keep it that way for as long as possible.

An Engineer in Wonderland - Cunning battery adapter

2012-02-08T16:30:59Z

Those clever guy's at Zebralight in China have come up with a neat way of making an LED torch compatible with both CR123 and AA cells.

Electrically, it just means a wider input voltage range - probably 0.9-4.0V.

But mechanically this has previously meant screw-on extension tubes to allow for the longer AA cell - maybe with a narrowed interior to deal with the AA's slimmer profile.

]]> http://www.zebralight.com/SC80c-AACR123A-Flashlight-85-CRI_p_85.html

It is a bit like those Presta-Schrader adapters in the end of bicycle pumps.

Looking for disadvantages, I surmise that the whole torch no longer gets shorter when the dumpy CR123 is fitted, and an additional insulating sleeve would be required if a switch was needed at the tail end of the torch.

'Alice'

Please don't respond below as our spam blocking system doesn't work and the inbox is overwhelmed by all kinds of generous offers from a multitude of rather annoying people.

Should you feel the need, respond to alice@electronicsweekly.com with 'Adapter' in the title.

No email addresses are collected for marketing (or any other) purposes from responses to this blog. I will keep it that way for as long as possible.

Let the breaking news come to you, with RSS

2012-02-08T14:58:52Z

The best way to get the latest electronics news as soon as it is published? RSS! Check out all the RSS feeds that are available for Electronics Weekly content. The feed for Latest News can be found here.

There are 10 Electronics Weekly feeds you can tap into: News Jobs Products]]> Mannerisms Gadget Master Made by Monkeys Electro-ramblings Directive Decoder Tech Startups Parallel lines To use an ElectronicsWeekly.com RSS feed you simply need to download and install a RSS reader. Alternatively RSS functionality is built into the personalised areas of sites such as Google & Yahoo, or in Internet browsers such as IE7 and Mozilla Firefox. RSS stands for Really Simple Syndication, by the way. And if you are unfamiliar with this technology, just check out the What is RSS section of our RSS page. electronics news

Video: CES 2012 - Samsung Transparent Smart Window

2012-02-07T16:19:20Z

At CES recently, the Samsung 22" and 46" transparent displays with touch screen interaction attracted a lot of interest. Here's a nice video showing it off.

Thanks to Chris Bartram of CDS for flagging this one.

Only Connect: On D-Type connectors

2012-02-06T09:35:38Z

Welcome to another post in the series by Nick Locke, of Nicab Ltd, who has over 15 years experience in the electronics manufacturing industry specialising in interconnection cable assembly.

Back in 1952 when Cannon first introduced the D-Series connector to the market they could not have imagined that they are still being used as the connector of choice for many interconnect applications.

This simple yet ingenious design has stood the test of time simply because it is so useful for a myriad of connectivity solutions.

We all know the d-connector but how well do you know it? Leaving aside the different number of ways and densities there are many different types. How many do you know? Well here is a simple guide to what is available and to enable you to make better design choices in the future. ]]>
1: Stamped & Formed Pin

The pins & sockets that are manufactured from a flat piece of metal (usually tinned brass) that is formed into the cylindrical shape of the contact. This is the most common type of contact used in commercial connectors and typically has a 50 mating cycles.

2: Machined Pin

Contacts are manufactured from a solid piece of metal (usually gold plated copper) that is machined into the shape of the contact. This is a high quality contact designed for demanding applications. These connectors carry in excess of 500 mating cycles.

3: Crimp Contact

Crimp Contact D-Connectors are very popular in the high end harsh environment specifically in the military market. Crimpling as apposed to soldering is generally seen as the termination method of choice for high end however, the arguments for and against are equally strong.

4: IDC Connector

The IDC D-type is just about the easiest to terminate and has the added advantage of being quick to assemble making this a extremely popular choice for simple data transfer. The main disadvantage is pin-outs are limited and cable choice is restricted to ribbon cable.

5: Filtered Connector

Filtered connectors offer greater protection from EMI/RFI. The connectors feature ceramic capacitor planar arrays and ferrite inductors to prevent interference and are typically used in environments where clarity of signal is critical. Connectors with filtering are by far the most expensive, however. If interference is an option then filtering is a must.

I hope this information has been useful and will enable you to make better designs in the process. When working with your approved cable assembly company be sure to ask them to offer their advice on which connector will be best for you.

Previous Only Connect entries:

* Only Connect: UL markings

* Only Connect: Quality of workmanship and value of UK Manufactured

* Only Connect: 3M Twin Axial Cable

* Only Connect: Workshop tools and cool, cute videos

* Only Connect: Guitar wiring

* Only Connect: NASA-standard quality

* Only Connect: Requirements & Acceptance for Cable & Wire Harness Assemblies

* Only Connect: CCA Conductors in Ethernet Cables

* Only Connect: Good design and the IEC Connector

* Only Connect: Identifying greener manufacturers (Going Green #9)

* Only Connect: New product design - InfiniBand CXP 12x QDR standard

* Only Connect: HDMI Connections a simple guide

Electronics Weekly Index - February 2012

2012-02-02T14:06:54Z

A periodic check on the market capitalisation of publicly quoted UK electronics companies...

I've just taken the February snapshot of industry market capitalisation, for our Electronics Weekly Index... see The market capitalisation of the UK electronics industry

With the number of companies stabilised, for better or worse this month can serve as the first benchmark...

How stands the industry? Well, it is currently worth at least £842.2 billion...
]]> recent results announcement, ARM Holdings is still leading the way, as an £8.0 bn company (13.5M shares priced at £5.96 at today's opening).

Take a look at the details >> (view the Companies tab for the figures)

Leave a comment below.

An Engineer in Wonderland - 15,000 lm torch

2012-02-01T15:32:50Z

LED torch maker 4sevens has demonstrated the production version of its 15,000 lm XM18 torch - or flashlight as the company would say.

Take a look at this video over at Geeky Gadgets

'Alice'

Should you feel the need, respond to alice@electronicsweekly.com with 'Torch' in the title.

Please don't respond below as our spam blocking system doesn't work and the inbox is overwhelmed by all kinds of generous offers from a multitude of rather annoying people.

No email addresses are collected for marketing (or any other) purposes from responses to this blog. I will keep it that way for as long as possible.

Only Connect: UL markings

2012-01-30T19:27:45Z

Welcome to another post in the series by Nick Locke, of Nicab Ltd, who has over 15 years experience in the electronics manufacturing industry specialising in interconnection cable assembly.

In this week's blog post I am going to show you how easy it is to understand UL ratings on Cable.

This is often an area of confusion as we have the BS Standard, CSA (Canadian Standards Association), and (Underwriters Laboratories) ratings - it's hard to know where to start or which standard to adopt.

For many the default standard of choice is the UL for cable & wire. The main reason for this is the international association of the standard. Pretty much everywhere in the world recognises the standard. What's more, the leading brands such as Belden & Alpha use UL ratings as standard.

]]> Assuming we are also going to adopt UL as the standard of choice what do we need to know. Here is a quick guide to UL marking on cable direct from the UL website:

What is the relationship between the UL Standards for wire and cable and the National Electrical Code? The large majority of UL's wire and cable Standards are intended to be compatible with the installation requirements of the National Electrical Code (NEC). Some exceptions are boat cable, marine shipboard cable, and appliance wiring material. UL staff devotes significant resources to the development of the NEC, which is published by the National Fire Protection Association (NFPA).

Does an E-number on a product mean that it is UL Listed? No. The UL E-number is a valid identifier for the organization responsible for a product but not an indication that the product is Listed, Classified, verified or Recognized. Only the appropriate UL Mark -- on the wire or cable or on its packaging -- is a valid indication of UL certification. UL assigns a unique E-number (E and a 3- to 6-digit number for wire and cable products) to each applicant in every product category. To find the responsible organization for a product when the E-number has been used for identification, go to UL's Online Certifications Directory, select "Search By UL File Number" and enter the E-number.

Why are ampacity markings not permitted on UL Listed wire and cable, and not shown in UL wire and cable Standards? The ampacity of a wire or cable is the amount of current that the wire or cable can transmit without exceeding its rated temperature. An ampacity marking on a wire or cable or a reference to a specific ampacity for a wire or cable in a UL wire or cable standard is not feasible since ampacity varies according to the actual conditions under which the cable will operate. These conditions include the ambient temperature, installation environment (e.g., free-air), conduit or directly buried in the earth. The National Electrical Code provides two methods for the cable user to determine ampacity for a cable based on the installation conditions.

What does the term "verified" mean? The term "verified," when used in a UL marking, means that the product has been tested and complies with one or more specific requirement. These requirements may be safety- or performance-related. In the UL system, the words "Classified" and "verified" mean the same thing. For a complete explanation of "Listed," "Classified" and "Recognized," read more on the UL Mark.

What is the best source of information on the intended use of a UL Listed wire or cable product? The guide information for most of UL's product categories provides valuable information regarding intended use and installation requirements. To view this information, go to UL's Online Certifications Directory. Use the keyword search to determine the links to files that are appropriate. Each file contains an additional link to the guide information.

Do the style numbers for Appliance Wiring Material (e.g. 1015) have any significance? The significance of the numbering systems is as follows:

Style range

Description

1000-1999

Single conductor, thermoplastic-insulated wire

2000-2999

Multi-conductor, thermoplastic-insulated and jacketed wire

3000-3999

Single conductor, thermosetting-insulated wire

4000-4999

Multi-conductor, thermosetting-insulated and jacketed wire

5000-5999

Single and multiple conductor specialty items

10000-19999

Continuation of Section 1

20000-29999

Continuation of Section 2

For additional information, refer to the guide information for category AVLV2 - Appliance Wiring Material.

The Appliance Wiring Material style pages include text such as "Marking - see page 13." What document does this reference? The UL appliance wiring material style pages are currently being revised. References within the style pages are obsolete. Instead, refer to the guide information for AVLV2 - Appliance Wiring Material.

I hope this has helped you and look out for my future blogs on this subject designed to help you improve your knowledge and build better products!

An Engineer in Wonderland - How wings really lift

2012-01-27T12:02:07Z

From the University of Cambridge: A one minute video sets the record straight on a much misunderstood concept.

The University said:

It's one of the most tenacious myths in physics and it frustrates aerodynamicists the world over.

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"A wing lifts when the air pressure above it is lowered. It's often said that this happens because the airflow moving over the top, curved surface has a longer distance to travel and needs to go faster to have the same transit time as the air travelling along the lower, flat surface. But this is wrong," he explained. "I don't know when the explanation first surfaced but it's been around for decades. You find it taught in textbooks, explained on television and even described in aircraft manuals for pilots. In the worst case, it can lead to a fundamental misunderstanding of some of the most important principles of aerodynamics."

To show that this common explanation is wrong, Babinsky filmed pulses of smoke flowing around an aerofoil (the shape of a wing in cross-section). When the video is paused, it's clear that the transit times above and below the wing are not equal: the air moves faster over the top surface and has already gone past the end of the wing by the time the flow below the aerofoil reaches the end of the lower surface.

"What actually causes lift is introducing a shape into the airflow, which curves the streamlines and introduces pressure changes - lower pressure on the upper surface and higher pressure on the lower surface," clarified Babinsky, from the Department of Engineering. "This is why a flat surface like a sail is able to cause lift - here the distance on each side is the same but it is slightly curved when it is rigged and so it acts as an aerofoil. In other words, it's the curvature that creates lift, not the distance."

Babinsky is quick to stress that he is far from the only aerodynamicist who is frustrated by the perpetuation of the myth: colleagues have in the past expressed their concerns in print and online. Where he hopes his video will help debunk the myth once and for all is by providing a quick and visual demonstration to show that the most commonly used explanation cannot possibly be correct. The original video, created by Babinsky a few years ago using a wind tunnel, has now been re-edited in high quality with a voice-over in which he explains the phenomenon as it happens.

Babinsky's research focuses on the fundamental aspects of aerodynamics as they relate to aircraft wings, Formula I racing cars, articulated lorries and wind turbines. One of his visions is to design a wing that will enable aircraft to fly faster and more efficiently. Using a massive wind tunnel within the Department of Engineering, Babinsky and his team have been modelling the shockwaves that are created on aircraft wings and that restrict the plane's top speed.

The newly released video will support lectures Babinsky will be giving as part of a series of University of Cambridge Subject Masterclasses aimed at Year 12 school children: "It's important to put out this video because when I give this lecture to school kids I start by giving the wrong explanation and asking who has heard it and every time 95% of the audience puts their hand up. Only a handful will know that it is wrong."

There is a series of University of Cambridge master class videos aimed at Year 12 school children:

'Alice'

Should you feel the need, respond to alice@electronicsweekly.com with 'Wings' in the title.

Please don't respond below as our spam blocking system doesn't work and the inbox is overwhelmed by all kinds of generous offers from all kinds of rather annoying people.

No email addresses are collected for marketing (or any other) purposes from responses to this blog. I will keep it that way for as long as possible.

Gadget Master compo sees Android IOIO board up for grabs

2012-01-25T08:30:59Z

Just a quick post to flag that you can win an Android-related piece of kit on another Electronics Weekly blog - check out the current compo on Gadget Master.

Specifically, up for grabs is the IOIO board (pronounced "YoYo"), from SparkFun. It is an easy way to get I/O from an Android smartphone's USB connection (OS versions 1.5 and greater). ]]>
To have a chance of winning the competition you need to answer one question correctly (based on a set of Android-related blog posts).

Enter the competition >>

Picture Gallery - CES International 2012

2012-01-24T08:46:58Z

It's like with London buses - you wait ages for one Picture Gallery and another one comes along straight after it!

Following on from the recent Spy Glider series, check out our picture gallery of a certain consumer electronics show that took place in Las Vegas.

Take a look at the people, gadgets and keynotes at CES International 2012, including the Sony Ericsson SmartWatch, the Invoxia NVX610, a PowerBag, the GreenWave Reality energy management system, keynotes from Intel and Microsoft, and more...

View the latest photo gallery >>

View all Electronics Weekly photo galleries >>

Only Connect: On education in electronics

2012-01-23T13:36:21Z

Welcome to another post in the series by Nick Locke, of Nicab Ltd, who has over 15 years experience in the electronics manufacturing industry specialising in interconnection cable assembly.

They say that if you always run your car on empty eventually it wall cause damage to the engine and cost you more in the long term, I believe it is the same for your mind.

If we only invest in the minimum to get by we will mostly just get by. However, if we constantly keep our minds topped up we will run in peak performance which leads to long term happiness, and isn't that what we all want?

It's not easy, it takes hard work and more effort but then anything worth having is always harder to gain. If you work in a highly technical industry such as ours it is well worth taking the opportunity to improve your knowledge, and it is possible. After all, learning about something your are interested in is always easier. ]]> IPC Training starts from the basics through to advanced assembly techniques. For the more technical a short course is a excellent way to brush up on your skills.

Oxford University does some great short courses, as do many academic institutions throughout the country.

For those who don't consider themselves as technical, then I can highly recommend the Make series of videos. I strongly recommend EVERYONE subscribe to this YouTube channel. They make electronics and engineering so easy to understand!

Finally, now for something completely different, I want to acknowledge the winners of this year's Elektra award for Passive & Electromechanical Product of Year: Harting - Han-Yellock connector system (pictured above).

It's a great system and well worth the award. It proves that simplicity is the key to great design. Harting are a fantastic company with brilliant products, often copied but never bettered!

Previous Only Connect entries:

* Only Connect: Quality of workmanship and value of UK Manufactured

* Only Connect: 3M Twin Axial Cable

* Only Connect: Workshop tools and cool, cute videos

* Only Connect: Guitar wiring

* Only Connect: NASA-standard quality

* Only Connect: Requirements & Acceptance for Cable & Wire Harness Assemblies

* Only Connect: CCA Conductors in Ethernet Cables

* Only Connect: Good design and the IEC Connector

* Only Connect: Identifying greener manufacturers (Going Green #9)

* Only Connect: New product design - InfiniBand CXP 12x QDR standard

* Only Connect: HDMI Connections a simple guide

* Only Connect: New investment in the motor industry's high-end

* Only Connect: My personal connector top ten

* Only Connet: Marine manufacturing and growth

OhmArt Cartoon: Logic Families

2012-01-20T14:14:26Z

It's well overdue time for another in our series of posts featuring the excellent electronics cartoons from OhmArt! Check out more on Barney's blog, too...

This one takes us into the rather strange world of Logic. Grandfather Aristotle has a lot to answer for!