TDK Corporation of Japan introduces high-performance LED technology to its iconic billboard in London’s Piccadilly Circus on August 3 2010, opening up new possibilities for this world-famous London landmark. The new technology will allow the use of high-quality moving images in full-colour, helping to catch the attention of passersby and to increase awareness of TDK.By replacing the existing neon tubes with LED lighting, an energy-saving technology, TDK is also helping to cut its environmental impact by 25%, despite upgrading to a more powerful technology. The billboard will feature TDK’s slogan “The power of creative thinking” alongside famous sayings from historical figures on the theme of creativity, launching a new campaign that is designed to reinforce the value of creativity, which is at the core of TDK’s brand image.
TDK has a global portfolio of advertising signs that spans three continents and is found at four famous locations: Times Square in New York; Piccadilly Circus in London; the Ginza 4-chome crossing in Tokyo; and Shanghai, China. As one of the most popular tourist spots in the world, Piccadilly Circus is a vital part of TDK’s billboard strategy, and it now joins New York and Tokyo in boasting the latest LED technology. TDK now intends to develop more visual displays using LED technology and utilise them in its corporate PR activities.
It is hoped that the large LED screen will enable Londoners, as well as visitors to Piccadilly Circus from all around the world, to draw inspiration from the great insights of the past. Through this new marketing concept TDK hopes to increase awareness of its global marketing activities, and thereby develop and enhance its global image as a state-of-the-art electronic components manufacturer.
One area of confusion in production safety testing is the dielectric strength test, sometimes known the as dielectric withstand test or “hipot” test.
This test is usually applied between the secondary output and chassis ground and then between the AC connection (primary) and ground / secondary. This test can identify any assembly errors such as a pinched wire.
It is important to ensure to short the line and neutral together during the test, and when making the primary to secondary test, connect the secondary side to chassis. Short the output terminals together if testing a standalone power supply. Failure to do this can result in damage to the power supply.
A routine question is “should the test voltage be AC or DC?” The majority of power supply manufacturers use a DC voltage because the leakage current through the “Y” capacitors can mask another fault.
The “Y” capacitors are identified in a very simplified diagram below are used to reduce EMI and electrical noise.
As can be seen, applying an AC input to chassis hipot test would result in mill-Amps of current flowing through the capacitors
The majority of safety standards allow DC hipot voltages. Instead of applying 1500VAC, one would use the peak voltage of the AC, √2 x 1500 = 2121VDC. Add 10% to reduce the test time from 1 minute to 1 – 2 seconds.
Apply the DC voltage slowly to allow the capacitors to charge up without tripping the current limit of the test equipment. Remember to discharge the capacitors after the test.