Wire & Cable Technology News

Though the vast majority of power cables today transmit alternating current, high voltage direct current (HVDC) transmission lines may power the future. DC transmission lines have lower losses and the transmission lengths are practically unlimited due to the elimination of the capacitive currents. DC transmission is also environmentally friendly.

Last month, the European Commission (EC) called for construction of regional electric transmission connections to distribute solar and wind power across Europe. It is part of their plan to boost renewable energy generation from 8.5% of European energy consumption to 20% by 2020 — and even more thereafter.

We are all learning to do more with less. In the power connector arena, customers are pushing manufacturers to develop products with higher current density, lower profiles, and increased airflow above and below the connector. One trend is to offer connectors that can handle both power and high-speed data connections.

As data speeds sent over copper cable get faster, knowing the cable's characteristic impedance becomes more important. While spec sheets for coaxial cable usually include this parameter, it's often missing from the spec sheets for most twisted pair cable. When this is the case, here are the calculations that you'll need to make.

This HV wiring analyzer performs open, short, and miswire tests up to 500 wires per second. It also has a hipot function with test voltages up to 1500 VDC and 1067 VAC, and a rugged and transportable solid-state hard drive. With a Windows touch-screen interface, the analyzer speeds testing of cables, connectors, harnesses, and panels.

Some test engineers think that you can find broken strands in a wire by turning up the test current and 'burn out' the remaining strands. This app note shows that nearly all of the strands in a 19-strand wire would have to be broken for the technique to work. More importantly, the practice isn't practical.

It isn't cable, but it acts like one. Scientists at Sweden's Chalmers University of Technology say DNA molecules function as miniature optical fibers. The DNA forms a scaffold for chromophores with overlapping absorption and emission bands, allowing energy transfer. The discovery may aid the development of photonic optical microprocessors.

The Hard Rock Park in Myrtle Beach, SC uses a combination of copper and fiber optic cables. The wiring handles voice and data transmission, fire alarm systems, lighting control, building automation, security, and audio/visual systems. It uses two 96 strand, singlemode fiber optic cables and a 24 strand, 10 gigabit, multimode fiber.

If you are involved in vertical industries including automotive, construction, aerospace, transportation, and communications, plan now to attend Interwire 2009, which will convene in Cleveland from April 25-30, 2009. The technical program will feature more than 30 presentations covering spring wire, bead wire, plastic deformation, steel tire cord, copper alloys, straightening, resistance heating, and more. A two-day course on the fundamentals of wire manufacturing is also being offered.

Barbed wire has been is use for more than 140 years to protect property, crops, and livestock. The Devil's Rope Museum claims to be the largest, barbed-wire, historic museum in the world. Located in McLean, TX and housed in a former brassiere factory, the museum is home to thousands of barbed wire specimens. If you can't make it to McLean, you can always visit the Web site.

I Say AC, You Say DC

Can we increase the power-per-square-meter of land use? Some engineers say that HVDC transmission lines offer many advantages. Will Edison prevail over Tesla? Do the advantages justify a switch?