Section I: The Case For On-site AC Regeneration

Canadian manufacturer PurePower opened it's doors 5 years ago with a unique idea. Instead of simply putting a band-aide on dirty, unstable power from the local power utility, as virtually all the other power conditioners did, they would throw it out and start from scratch, create brand new electricity "isolated from the grid".

 This idea, to "regenerate" new electricity was nothing new to them. As power quality management experts in the commercial and industrial sectors, they knew first hand that hospitals, labs, and precision manufacturers worldwide need battery-grade reference power, de-coupled from the local power company, running perfectly 24/7/365. When the electricity must be perfect, on-site regeneration is the solution. PurePower was born to meet that need for audiophiles and videophiles whose investment in their AV systems justifies the same kind of effort and cost.   

The specifications for the electricity we use in our homes and business's is meant to serve the greatest number of consumers, or as the Public Utility Commission calls it, "the greater good". It might be fine for running our refrigerators, toasters, air conditioning, lighting, and computers, however, recent tests by Rx Monitoring of Bedford, New Hampshire, a company that measures power quality for large commercial entities as well as consumers, proves without a doubt that the utility supplied AC is not close to being good enough to operate today's high-end audio video systems.

A recent customer in New Jersey, who owns a large, expensive AV system housed in multiple racks, experienced repeated shut-downs. At first glance, if the circuit breaker is tripping, the usual solution is to increase the amperage, for example from 15 amps to 20 amps, to get more power.   The consumer installed dedicated 20 amp circuits but the shut-downs continued. Clearly, further study was required and that's where Rx Monitoring entered the picture, by referral from our local dealer, Bravo AV.

Rx makes a patented test measurement device that was installed temporarily on the main electrical  panel, at the point of entry. It ran for three weeks, producing a 260 page report, keeping track of every electrical event during that period. All the sags and surges are recorded 24 hours a day. Power transients are also recorded, and these little spikes, happening at the sub-cycle level, turned out to be the culprit. Quoting directly from the Rx report:

"The following waveform has a nice clean sine wave on the left side  ...

...but the right side of the waveform is highly distorted.  Notice how the right side of the waveform crosses zero three times within 2 milliseconds instead of the normal twice every 16 milliseconds. This crossing is what many electronic components (e.g. Diodes) use to turn on or off, and since 

many components have dozens of these in a circuit, some diodes will turn on at the wrong time instead of in  sequence. This causes the component to reverse bias and degrade (or eventually blow-up) due to excessive heat. The "false" zero crossing also causes "timing" issues and many circuits use the 60Hz sine wave to time the turn-on of components (in a closed feedback loop) and these false crossings would cause random errors and resets"

The "aha" moment has arrived.   Read on:  

"The waveform above shows multiple times that the sine wave had this low frequency distortion that causes high-end electronics problems. This waveform requires a "double-conversion AC regenerator" to rebuild a new sine wave.  It is caused by the Utility turning on Power Factor Correction (PFC) capacitors that are a required part of the electrical distribution system. The waveform that it causes is allowed by the Public Utility Commission (PUC) as the "greater good" for the most people and in their opinion any device that is vulnerable to it would require a "customer" provided solution." The capacitors are causing the transients at times of peak demand.

Below is an example of a momentary sag, also common on a residential circuit.  Lasting less than 8 milliseconds (one-half a cycle) this waveform distortion also requires AC regeneration for total system performance.  


"Overall, the power quality was not found to be conducive to powering high-end audio visual equipment and distortion, degradation and eventual damage to the equipment is possible.  Most importantly, the quality of the signal will be affected and that can compromise the sonic and video quality.  Our engineers have evaluated the PurePower AC double conversion regeneration device and the specs indicate that it will be audibly quiet, provide the correct level of power regeneration and provide quality and protection."  





Section II - What's In Your Wall Outlet?

Above is a chart from the RX report that summarizes the results of the 21 day monitoring of the Utility supplied AC power at customer's Home. Note that during the monitoring period the voltage varied from a low of 112 volts to a high of 252. There were literally hundreds of sags, transient and power distortion "events" captured - and each one was recorded and graphed in the preparation of this very extensive and detailed report. In the summary chart the severity and significance of the power problems are rated with a color key from severe to acceptable. 

Below is the log form a single day - December 22. It is clear the utility was not providing our customer with a Christmas present of good power quality.

Above is a chart summarizing some of the different voltage sag types captured during the monitoring study. Notice how the left hand side of the chart is in percent of voltage (either 120V or 240V). The Red area is very bad and the farther to the right the "dots" are, the longer in duration (time) of the sag. The longer the voltage events, the more damage can occur. It should be noted that this chart illustrates sag events unacceptable for high-end electronics. But the Utility finds it acceptable to deliver  power of this grade. The Utility measures things in minutes while electronics measure things in picoseconds {A picosecond is one trillionth of a second (0.000000 000 001 seconds)}. The transient chart clearly indicates the threat posed by these short (many are in the nanosecond range) voltage events. They are scattered throughout the test period and many are greater than 200 volts above or below nominal.

Their short duration means they don't pack the power of a major surge event - and they go unnoticed by the homeowner since they do not cause lights to flicker. However, they can do serious damage and even explosive failure to high power transistors and other sensitive solid state electronics.


Above is the voltage data log for a 24 hour period. Note how the voltage vacillates constantly from minute to minute and and hour to hour. It is also clear that the utility voltage at midnight is significantly higher than at 7 pm, hence the familiar audiophile comment that the system always sounds better at midnight. 

This is a typical day except for the very dramatic voltage drop in the early AM.



Section III - Why On-Site AC Regeneration is required.


The efficacy of on-site AC regeneration in redressing the power quality problems associated with Utility delivered AC power  can be easily demonstrated. When AC power with distortion, noise, voltage instabilities, sags, power outages and even unstable frequency is used as the source power supply for a PurePower double conversion AC regenerator the result is dramatic. The output of the regenerator is pure power with a new, clean, stable voltage sine wave. It doesn't matter how distorted the input - the output is always the same. It is a complete solution.

Other Power conditioning technologies can ameliorate one problem or another -  but never completely remove it.  AC regeneration has been the preferred power quality solution in high tech, scientific and sensitive electronic installations for a number of years. Now there is an AC regenerator designed specifically for High end Audio and Video.


Bad Power in

Clean power out

Highly Distorted Power in

Low distortion out

From company headquarters in the historic city of Cambridge Ontario, company founder and president Damian Janzen said "Owner's of high end AV gear know their systems can't reach their full performance potential if the inbound power is unstable, noisy, and distorted. PurePower products convert the inbound AC from the local service provider to DC, removing all the noise and distortion in the process, before creating a brand new AC voltage sine wave, augmented by it's own internal battery system. The battery system provides total isolation from the local power grid, so that the very common voltage sags, surges, and transients can't affect the AV system, even in a blackout". 

For technical specifications and a more detailed explanation of AC regeneration technology, visit and read the technology pages.


If you own a high performance system, and suspect your AC power is degraded, PurePower has the solution you have been searching for. 

If you already know you have problems, you  can simply go to and tell us about your system. We will provide a free Power Audit to help you choose the correct AC Regenerator.

If you are unsure of  your AC power - and you want the world's most definitive Home power quality analysis - just email and ask about PurePower's brand new on site power quality audit. We can arrange a sophisticated engineer supervised PQ monitoring program just like the one described in this white paper. It is the definitive analysis of your utility power.




Copyright 2003 - 2009  PurePower Partners LLC.