"Looking At" Line Power

[Grainger49]

My revelation on clean power from the PS Audio P300 made me wonder what is on my incoming power.  Can I take a 120V/12.6V transformer and look at a reasonable facsimile of the incoming power? 

I know the induction of the transformer will filter some high frequencies, and so should equipment power transformers.  But they must not filter as much as I would expect.  The winding capacitance might also filter out something.

But the question stands, can I see a reasonable facsimile of the incoming power?

 

[VoltSecond]

Standard 120V to 12.6v transformers saturate at the zero voltage crossings so any voltages read at that point will be off a lot. 
A 240V to 12.6V transformer used as a 120v to 6.3V transformer has a chance of having some fidelity.

Feed a square wave into the 240V side. Add a cap to the 6.3V side until the ringing period approximately doubles. Then add a resistor in series with the cap to get minimum ringing; now the bandwidth is about as good as it will get.

If you really want to look at the 115V, I'd build a high voltage instrumentation amp with ~1 meg input resistors with each resistor input rated for ~1000V.

 

[Grainger49]

Thanks, but I am wondering if there is noise, spikes or notching, on my incoming line.  Industry is not that far away.  The changes with the P300 was so dramatic that I now wonder what the incoming line looks like.  

I know that a small transformer would remove the ground reference allowing me to attach a scope channel across the output without any fear of a grounding problem.

I do have 3 or 4 industrial 480/120 transformers, a couple of them are multitaps, if that would yield a cleaner picture of the incoming noise.

 

[VoltSecond]

Note: I recommend a THQL Surge in the breaker panel in addition to what ever local filtering you use.

The 480 to 120 will give you a look at the low frequencies, but not accurately display everything.

 

[4krow]

Grainger, I know that this is an old thread, but I would like to chime in here. I too, owned a PS300, and like you, noticed big differences with it 'in circuit'. Later on, I sold it(big mistake) and bought a PS Premiere. The new unit had an analyzer built into the display. In my case, incoming harmonic distortion was at 3.5%    Output showed about .3% if I remember correctly. Of course, both units have quite a few variables with the waveforms (very cool), and that affected the efficiency of the equipment.

 

[Grainger49]

Greg,

Nice information.  I am also using my P 300 to power and adjust the speed of my VPI HW-19.  Almost all HW-19 series tables I have read about and heard don't run 33.333 RPM.  So I am limited to the sine wave only for vinyl.  I should give it a try on CD (not as a source for the CDP).

I didn't know that the PPP did power quality analyzing. 

 

[4krow]

Grainger,

  I don't quite remember, but as I recall, there an upgrade for the PS300  called multiwave 1  or 2. It has a lot of combinations, but there is also a special freq just for turntables. 

  On a former note, I had to sell the Premiere because there were some power issues in my city block that was tripping it on in the middle of the night, and there was never a fix for it. I now own a Balanced Power Tech  power treatment unit. It has balanced power which is the most important upgrade 'for free' that you can get, plus it has completely separate windings for each set of outlets that acts as though you have a dedicated line for each outlet. VERY COOL.

 

[Grainger49]

I got the last Multiwave II+ that PS Audio had about a year ago.  It took a week for one of the engineers to find it in an office.  All the manuals I have seen warn not to use Multiwave on any product using a synchronous motor.  Turntables and tape decks were called out specifically.  They also mention any equipment with a fan in it like an Ampzilla.  (I mention Ampzilla, they don't)

BTW, the output of PS Audio's regenerators is balanced power, +/-60V symmetrical around ground.  Whenever there is a lightning storm here I unplug my P 300.  IMHO PS Audio designed the power supply for the early (only ones I have seen inside) regenerators poorly.  They put 110V on 100V caps.  And then there were massive capacitor failures.  Go figure.  PJ would never do that! ! !