Re: article 647
Ken, it is really quite simple. The traditional distribution system is unbalanced, meaning you have a grounded conductor (neutral). Having an unbalanced system allows small amounts of current (noise) to be injected into the equipment ground conductors via line capacitance, and filters installed L-G and N-G. This in turns creates small voltage drops in the equipment ground conductors referred to as common mode noise.
Common mode noise is picked up by input circuits like A/V inputs, RS-232 lines, data bit detectors, etc and then passed onto the signal processing equipment and an error voltage or noise is introduced. A good example would be a stereo system where you have several components powered from different outlets or sources. The noise is heard as a loud hum in the speakers. Or in data processing equipment the noise causes data bit errors in the data bit detector circuits.
Using a balanced power distribution system can solve these problems. In a balanced system the lines are symmetrically balanced with respect to ground. They do not use a grounded circuit conductor (neutral). The leakage currents (noise) is symmetrically balanced out of the ground circuit. Basically, what has been done here is to redefine zero. Actively, zero is now defined as the mean voltage differential of the AC sine wave. Reactively, zero is defined as the sum of everything around it.
A good source for these types of systems can be found at
www.equitech.com and in particular
http://www.equitech.com/articles/origin.html and
http://www.equitech.com/articles/enigma.html
This distribution system was originally developed by the recording and motion picture industry, but is now being implemented by the telecom and data processing industries. My experience has been very positive and I will continue to use this technology.
[ March 25, 2003, 04:11 PM: Message edited by: dereckbc ]
