Like many inexpensive desktop PCs, my Dell Dimension C521 lacks a serial port. But, don't write off serial communications which will continue to play important roles in industrial controls, point-of-sale terminals and other equipment. USB and Ethernet have a place, but simple serial I/O still solves a lot of problems.
For simple static-DC source-and-measure tests, familiar instruments such as power supplies, scopes, voltmeters and function generators work well. Dynamic DC-bias tests, though, involve sequencing and sourcing voltage and current, as well as making measurements. These bias tests require complex interactions among traditional instruments, and they can create setup and configuration challenges.
You found me! And I do hope that the journey to the back of the magazine was productive. It’s not often that someone has the luxury of a forum such as this column to tell a very large number of people that they are moving on but, as luck and timing have it, I do have this opportunity and I would like to take just a brief amount of your time to bid farewell to the readers of ECN as I leave my position as editor-in-chief.
Solid state lighting offers greater energy efficiency, as well as what are now still long-term cost benefits. Here, industry experts comment on the biggest challenges in the design and manufacturing of LED illumination and what is needed to make the widespread adoption of LED illumination by design engineers a reality. Follow the links to read the complete commentary.
Power factor is the ratio of the actual power used to the apparent (reactive) power that a piece of equipment draws from the alternating current (AC) line. The reactance of large capacitors or inductors can cause the apparent power drawn from the line to exceed the actual power used, resulting in low power factor (PF). The lower the PF, the more energy is lost along the AC power line. The result is higher electricity bills for the utility customer. That lost energy also lowers the capacity of the utility distribution system.
Most likely you know a bit about the Controller Area Network, also called CAN or CAN bus, developed for communications between equipment in vehicles. The CAN has spread into embedded systems, too, but unlike chip-to-chip I2C or SPI connections, CAN communications may occur between cards and systems over a bus that can extend from 10's to 100's of meters. (The ISO-11519 and ISO-11898 standards covers CAN protocols and physical-layer specifications.)
My first experience with a relay came about when a friend found a radiosonde -- a small balloon-borne weather instrument -- in the woods behind his house. My friend Ben wanted the parachute, so I got the electronics. As a kid of 11 or 12, the circuitry didn't mean much, but it included a simple relay I experimented with.
Electrostatic discharge (ESD) occurs when objects -- including people, furniture, machines, integrated circuits or electrical cables -- become charged and discharged. Electrostatic charging brings objects to surprisingly high potentials of many thousands of volts in ordinary home or office environments. ESD produces currents which can have rise times less than a nanosecond, peak currents of dozens of Amps and durations that can last from tens to hundreds of nanoseconds. Unless ESD robustness is included during design, these current levels can damage electrical components and upset or damage electrical systems from cell phones to computers.
Competitive telecom businesses have realized they can no longer design proprietary hardware. In response to this changed business climate, members of the PICMG, a consortium of industrial-computer vendors, developed PICMG 3.0, or the Advanced Telecom Computing Architecture (ATCA). Marc LeClaire, a product manager in the Advanced Blades and Servers Division at Kontron, stressed that the ATCA standard covers boards, enclosures, interconnections, communications, and other architectural components. "Designers must think of the ATCA as a complete architecture, not simply as a bus."
For years, synchronous parallel buses have served as the media for data exchange between digital devices. Timing issues, however, plague parallel buses at high clock frequencies and data rates, and limit their capability to keep up with demands of higher-speed computers. Over the past few years, serial-bus technology has advanced the computer industry because serial buses send self-clocking bit streams that eliminate skew associated with parallel buses. As a result, serial data rates have risen above 1 Gbits/sec. and newer implementations approach 3 to 6 Gbits/sec. As multi-gigabit data rates become common, however, signal integrity -- the quality of signal needed to properly transmit data to an IC -- becomes a paramount concern for designers.
I think the simplist productivity metric which should be used across the industry is the total number lines of code in the organization divided by the number of people who are working on that code (including QA as well as development).
The trend toward miniaturizing medical electronics devices also brings with it a number of challenges. In this month's edition of Brainstorm, we ask industry experts in the medical electronics market what they believe to be the most critical of these challenges and what current and developing technology is available to help the designer meet those challenges.
What do you consider to be the most important factors that will further the development of power management in portable systems? What do you think are some of the customer misconceptions about power management that must overcome to move the industry forward?
As I kid, I sometimes got frustrated with what I saw as my Dad not giving me a straight answer. For instance, I would say, “Dad, I need a hammer”. “What are you using it for?” he would say. “There’s a finishing nail sticking out the wooden floor in my room and I need to pound it back in.” (I grew up in an very old farm house.) “Then you need a rubber mallet, not a hammer.
Designers are always on the lookout for semiconductors and algorithms that help to boost the efficiency of appliances with a minimum addition to the overall system cost. Motor-control systems need to compensate for system input changes and can use control algorithms to ensure the efficient operation of the motor. Using advanced algorithms, such as a field oriented control (FOC), motor torque can be controlled dynamically, keeping it constant within the rated speed range (see Figure 1). Toward this, the most commonly used motor-control loop is the Proportional Integral Derivative (PID) controller, which comprises error calculation (reference minus measured variable), compensator (controller), and output generation to the system.