Wednesday, September 28, 2016
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
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
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.
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
Thursday, September 15, 2016
Tuesday, September 13, 2016
Monday, September 12, 2016
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.
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
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.