Balanced power supply - Technical Notes
Whatis Balanced Power?
Electric power is delivered to homes in a "single-ended" fashion with two wires. One wire, called the neutral, is always held at 0 volts. There is no voltage on it. The other wire, called the hot, carries all of the 230 volts AC. Balanced power converts the single-ended power to a balanced power system with both wires now carrying 120 volts AC, each out of phase with each other. The total voltage between them is then 230V. The ground wire is held at 0 volts.
How does it remove power line noise?
Transformers only respond to voltage differences between their leads. Power lines often have a type of noise called common mode noise which is present on both the neutral and hot wire. The Balanced Power Supply contains a massive toroid transformer that reject much of this noise.
What is a ground loop?
A ground loop occurs when different equipment grounds are at different voltages, causing noisy ground currents to flow between them. The Balanced Power Supply creates a new ground called a derived ground, that decouples equipment connected to it from these circulating ground currents in the rest of the house wiring. It also provides one common ground reference for all the equipment connected to it.
How does it reduce radiated fields?
Because the power is delivered by two out of phase signals, the electric fields produced by each should largely cancel. This reduces noise caused by radiated fields. This is same principal used with twisted pair cable but in reverse. Instead of rejecting noise, power carrying cables don't radiate noise in the first place.
How does it reduce interference between equipment?
Most modern electronic equipment uses switching regulators in their power supplies. These devices can produce RF noise that can couple through the power cord to other equipment. The balanced power supply provides a very low impedance to the connected equipment which shorts out this high frequency noise. Some users have reported improvements in large screen video performance.
The BPS2000 is balanced power supply. This unit runs 2000VA continuous load. With a 2 meter 230V input lead and three, 230V CTE (centre tap to earth) 13amp sockets.
Our Conditioning Balanced Power Supplies' CBS1500 and CBS2000 include a mains filtering component and a level of conditioning using a varistor.
There many different ideas as to what a main conditioner provides but our mains conditioner circuit removes transient spikes by using VDR's (varistors); in addition to the RFI suppression.
The simplest explanation of a mains filter is that the filter will let the basic 50Hz mins waveform through with the minimum of attenuation, whilst all other unwanted (usually high) frequencies are attenuated. The filter acts in two modes: it attenuates differential-mode (asymmetrical) noise (noise on either the neutral or live) & common-mode (symmetrical) noise (identical noise on both the neutral & the live).
The electrostatic screen also attenuates high frequency noise by reducing the capacitance between primary