“The Hardware Hacker”

Andrew “Bunnie” Huang has written a book that really pulls together the realities of launching new products in China, in a detailed way. It has a broad scope, covering engineering, business practices, and cultural norms for China.

The Hardware Hacke (Adventures in Making & Breaking Hardware)
by Andrew “bunnie” Huang
No Starch Press

Book Cover: TheHardwareHackerIf you are involved in management, engineering, accounting, support, or most any other area of high-tech electronics, you should read this book, especially sections 1 and 2. The author offers great insight and advice on bringing designs into production, particularly when production is moved to China. The first five chapters cover development and mass production of an open source design internet data “appliance” called “Chumby.” Here are some of the topics covered:

  • test plans and test equipment design
  • component selection
  • fake goods (identifying gray market or counterfeit parts)
  • required documentation
  • basics of creating a Bill of Materials (BOM)
  • packaging and shipping considerations
  • automation v. human labor in some processes
  • factory tours and “culture”

Go to full review

Posted in China, Chinese culture, gongkai, intellectual property, open source, outsourcing, shanzhai, test methods, Uncategorized | Comments Off

Desk Lamp is Unstable

With advances in LED lighting, this TaoTronics desk lamp looked like it would fit my needs, which were:

  • An adjustable (position & intensity) light to use with my “student” microscope. The ‘scope has a mirror for illuminating slides from below or with direct light from above.
  • A light source for macro-photography and close-up work.

desk lamp tips overThe most common complaint in the lower rated (1-3 star) reviews on Amazon cited functional failure of the light or the touch-control panel (used to vary brightness), so when I received the lamp, the first thing I did is set it up and run it through several on-off cycles, ranging from a few minutes to 24 hour on, for about 4 days.
> Link to full article and video

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New Connector Technology

Wiring harnesses for the B-17 World War 2 bomber (Click for full-size)

Wiring harnesses for the B-17 World War 2 bomber (Click for full-size)

In over 25 years of electronics troubleshooting on a wide variety of analog and digital equipment, some of it cutting edge, I have concluded that a majority of failures were due to failed connections. That is, components such as  switches, plugs and jacks, crimped wire terminals, circuit board conductor fabrication, and solder joints failed more often than the components they connect. In the 21st Century (I like saying that) connectors, other than optical systems, still rely on old technology: mechanical contact between conductors.

The good news is that Non-mating Connectors (NMCs) use a totally different technology to transfer signals and power, and hold great promise for increasing the reliability of electronic equipment. Read more..(in Reliability section)

 

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Patio Heater Safety Hazards

This blog has a section devoted to products of poor quality &/or design (see Quality Fail), but this post stands alone for an exceptional  failure which could endanger people and property.

The product is a large, standalone propane patio heater manufactured by Shinerich Industries in China. They are marketed in the U.S. under names such as “Charmglow”, “Fire-Sense”, “Blue Rhino,” and are commonly sold in “big box” stores and on Amazon.

In March, 2014, a gust of wind (est. 15-25 mph) blew the top reflector off! The metal screen had totally failed and broken apart. It was the only support for the hood. The metal was degraded to the point where it crumbled like a potato chip.
Play this video to see more details:

The heater was only used 10-15 times, and appeared to be in good condition, with only minor exterior corrosion. The unit was not being used at the time, so there was no fire danger.

Had it been on, with people gathered around, they may have been seriously burned by red-hot metal pieces. Even with the unit flame off, the large, heavy reflector could have injured someone or gone through a window. It flew about 15 feet away from the base, but not toward the house–we were lucky.

Root Cause

The metal screen was clearly not suitable for use. As a comparison, I tested a similar unit (nearly 7 yrs. old) owned by a neighbor, and the screen material was strong–it withstood light hammer blows with no bending or cracking.

But nobody was hurt…

In early April, I reported this failure to the manufacturer, to CSA (they certify these), and to the U.S. Consumer Products Safety Commission. I have kept samples of the metal screen, and offered to submit them for forensic investigation. CSA has not responded to my reports or offer of samples of the screen. I believe part of this is because there were no injuries or other damage, and CSA knows that the manufacturer subverted or avoided the surveillance in the factory to use a substandard metal, not certified for use in a propane flame environment. In other words, “CSA Certified” is no guarantee of a safe product. But again, “Nobody got hurt and you don’t have any damages to claim,” is probably the main concept that applies here.

Conclusion–waiting!

On Amazon.com, there was a similar report involving a 2 yr. old unit (ours was approx. 4 yrs. old), but I have not been able to get any more details. This is disturbing, because there may be hundreds of these waiting to fail. In the 21st century, there are certainly high quality metals that have been designed for this use, but Shinerich did not use such a metal on this particular unit. We now have a large large, useless heater that would be cheaper to replace than repair. If there is any news on this situation (contact from CSA, etc.), I will create a new post.

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Medical Devices – 10 Regulatory Pitfalls

Avoid the infamous “Showstopper”

The IEC60601 standard isn’t simple to understand. Experienced engineers not trained in this standard may present sound designs but still have problems with certification. There are many grey areas when it comes to component certifications. The better you understand the standard, the more quickly (and cheaply) you can get the product certified. Here are ten pitfalls I have encountered as a Product Safety Engineer:

  1. Power Supplies – Leakage and Temperature
    -Some Power Supply Units (PSU) are not fully certified for the type of medical device you may design. They may be acceptable for some applications, but not all. Low leakage current is critical and requires close examination of the power supply CB report.
    -The critical components in the power supply will be monitored for maximum temperature in the final product. The original PSU tests are done in open air, and your product will require venting, fans, etc. that affect the temperatures.
  2. Bottom Vents
    A chassis with bottom vents has very restrictive requirements to meet. Under certain conditions, the device may comply, but it’s best to avoid using bottom vents.
    For details, see IEC/UL60602, Clause 11.3b, Table 25.
  3. Fuse Selection
    Fuses have blow curves, so the current rating can be deceptive. It won’t instantly open with that exact current–it takes time. You want the fuse to open before other hazards occur, and this requires testing to ensure the fuse works, but isn’t too sensitive to routine surges.
  4. Laser Certificaton
    If lasers are used, test reports and certifications will be closely scrutinized by the lab. The report must include testing of the failure modes for the laser. Many reports are incomplete and have skipped these tests! Refer to IEC60825-1 for details.
  5. Battery Packs
    Standards for batteries, especially lithium-ion and other rechargables, have tightened considerably. You may select a certified battery cell, but if it is packaged as a multi cell battery, further testing is required. Example: You have selected a certified 1.5V NiMh cell and put 4 of these into a 6V package. Complete testing of the pack is required. Tests include failure modes and can be destructive. The testing can be time consuming and expensive. It’s best to find an existing certified battery pack, if possible.
    Refer to the IEC62133 (supercedes UL1642) and IEC60086-4 standards.
  6. Circuit Board Thickness
    For circuit boards, it’s easy to over-focus on creepage and clearance for insulating high energy or voltage circuits. Be aware that board thickness between layers is just as important. This is covered under Distance Through Insulation (DTI) in the standard.
  7. EMC Requirements
    IEC 60601 requires rigorous testing for RF interference and susceptibility.
  8. Plastics Flammability
    Selection of plastic for a housing requires consideration of flammability. Typically, you find a suitable plastic by checking a database, such as the UL certifications that have detailed listings and ratings. Make sure your design uses a thickness that is listed. If you use a 1mm thickness, and the minimum listed is 1.5mm, you fail!
  9. Plastics and EMC shielding
    Metal coatings inside a plastic case may be necessary to meet EMC requirements. The combination of plastic and metal must be certified. This is to ensure the metal doesn’t break free of the plastic and cause problems with EMC and safety (e.g. shorts caused by metal flakes).
  10. Manuals for Users, Operators & Maintenance
    This documentation, along with the product label are considered part of the product and therefore must be submitted with the product sample. If possible, avoid big production runs of these documents until final approval is received from the test lab.
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Voyager 1 Spacecraft – very far out!

Great Red Spot on Jupiter

Early in the mission, Voyager 1 sent this image of the Great Red Spot on Jupiter.

The Voyager 1 Spacecraft, launched by NASA on Sept. 5, 1977, is nearing the edge of our solar system. It has traveled over 18 billion kilometers, and continues to function as designed. This is a case where quality exceeded expectations.  More on Quality Excellence.

 

 

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