Wednesday, September 28, 2016

Exploding Washing Machines

ABC News reports here on a U. S. Consumer Products Safety Commission (CPSC) warning about some Samsung washing machines that exhibit extreme vibrations that witnesses describe as explosions.  The cause of the vibrations appears to be a part that can come loose, allowing the spinning tub to move.  This problem does not appear to have any computer-related cause. It is, however, an interesting example of the large amounts of energy that is harnessed by everyday objects.

Saturday, September 24, 2016

Computers as Components 4th edition

The fourth edition of Computers as Components is now available.  A highlight of this latest edition is coverage of the Internet of Things: IoT devices, protocols, systems, and applications. You can find out more about the book here.

Thursday, September 22, 2016

Internet Security Probes

Respected computer security expert Bruce Schneier reports here that many components of the core Internet infrastructure have been probed in a manner that suggests that some entity is trying to figure out how to take down the entire Internet. A complete Internet failure---even failure of a significant piece of the Internet---would pose many concerns. One of those concerns is the operation of critical infrastructure that relies on the Internet. Many agencies and companies are working to address critical infrastructure vulnerabilities; this latest report gives those efforts added impetus.

Puerto Rico blackout

7 News Miami reports here on a power blackout, apparently of the entire island of Puerto Rico. This blackout was due to a fire, not computer problems. But it does illustrate the challenges we face in providing reliable critical infrastructure.

Wednesday, September 21, 2016

U.S. DoT Policy on Automated Vehicle Development

The U. S. Department of Transportation releases here a statement on its policy on automated vehicle development.

Remote Hack of Tesla

Reuters reports here on a remote hack of a Tesla automobile.

Thursday, September 15, 2016

Uber Driverless Vehicle Experiment

This article from the Associated Press, printed in the Houston Chronicle, reports on Uber's driverless car experiments in Pittsburgh.

Tuesday, September 13, 2016

Monday, September 12, 2016

Hello, Mechanical Sewing Machine

 I have written several posts about the trials of finding a good sewing machine.  I finally decided to buy an industrial model.  The store owner told me that it would last 20 years.  I think that he underestimates.  The way this machine is built, I plan to leave it in my will.  I mention it here as an example of heavy-duty design.  So much modern software and electronics are designed to be throw-away; the modern smartphone is designed to last for 2-3 years.  While disposable devices certainly have their place, I hope that we don't lose the ability to design solid, long-lasting devices.

English is not the first language of the manual.

This machine has an oil pan.  It uses splash lubrication just like a car engine. The lubricant is mineral oil.  It has a sweet smell and should stain less in the unlikely case that it spills.  I have read quite a few complaints on the Web about the plastic gears used in portable sewing machines and other home appliances.  As I understand it, plastic gears perform better in lubrication-free environments; I don't think the average homeowner wants to oil all their appliances.  I'd rather have good plastic gears than cheap metal gears.  But the drivetrain of this machine is impressively solid.

The speed control connection to the motor is a steel rod. The pedal on my portable machine proudly proclaims "Electronic."  No wimpy electronic control here.

This machine came with a servo motor. Older machines use clutch motors, which must have been both loud and a little smelly. This machine runs at 5000 stitches per minute---that's 25 meters per minute.  The knob on the motor allows you to set the maximum speed to a lower value.  I was a little worried about the sensitivity of the speed control, but it has proven to be easy to control.

You say you want vibration control? Just the head of this machine weighs 75 pounds.  Add in the motor and table and it tips in at over 100 pounds. That's vibration control technology straight from Sir Isaac Newton---a 100 pound body at rest tends to stay at rest.

This machine only makes one stitch, a straight stitch. It is also mechanically set for medium-weight fabric. To adjust it for either very light or very heavy fabrics, I have to use a screwdriver to adjust the feed dogs that feed the fabric. I also have to adjust the thread tension by hand.  Home portable machines have sensors and controllers that automatically adjust all aspects of the machine to adapt to the fabric conditions.  They also perform a lot of different stitches; high-end machines may perform hundreds of decorative stitches.  But their stitches aren't as uniform as the ones produced by industrial machines.  Building a machine to do one thing well has advantages.

Saturday, September 10, 2016

NASA Github site

Dimitrios Serpanos pointed me to the NASA github site.  It contains a wealth of NASA code ranging from the 1970s to recent developments.

Near-Field Audio

EE Times reports here on the NXP chip used for near-field audio on the iPhone 7.

Killer USB Drives

Extremetech reports here on a USB device that will destroy a computer when the drive is plugged into the USB port.  This device works by applying a large negative voltage.  As a result, it needs no knowledge of software and can work on any type of device or operating system---it simply fries the electronics.

Friday, September 2, 2016

Galaxy Note 7 Battery Fires

In case you were wondering why batteries are important, see this Anandtech article on reported battery fires in the Galaxy Note 7.

Battery Technology

Extremetech posted an interesting article here on the non-technical challenges we face to improve battery capacity and lifetime.