My DIY Balanced Power Conditioner

[Glen B]

I recently completed construction of my DIY balanced power AC line conditioner and thought I would post some pics.

[JonMarsh]

Nice looking work, Glen! That does look like a labor of love.

What do you think of the Auricaps in a line filtering application?


Regards,

Jon

[ThomasW]

Hey Glen,

Nice job!

It has that industrial no-nonsense look....... :T

Bet it weighs a few lbs though ...... :E

[Glen B]

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[Glen B]

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[Ten 99]

Dang...

That's nice Glen.

Would you mind sharing the cost breakdown you spent on that? I'm wondering how much went to what parts. I know that you didn't mess around and cut corners. I'm thinking I might be inclined to cut a few, and I'm curious where I could spend money versus not spend it.

Also, I gather that since you've seperated transformers between analog and digital devices, that running both on the same transformer can cause an undesirable affect?

Puts some high heels on her, and a mini-skirt!

[Glen B]

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[ThomasW]

As Glen has indicated there a 'levels' of isolation.

The use of individual transformers certainly provides the best isolation. But as noted it's also the most costly. Using a single larger transformer and putting individual RFI/EMI filters for each outlet, is the next best choice.

Here's a pic of one of the first balanced power devices I bought. The unit provides each of four pieces of gear (250VA max draw/device) with it's own transformer. Soon it's going be upgraded with the addition of individual RFI/EMI filters and other assorted goodies..... :T

[Ten 99]

Thanks guys. That helps to understand. I suppose when I see (for instance) some multi-channel amplifiers out there that this is what they're doing -- some just share one large toroidal, while others seem to have a smaller toroidal for each channel on the amplifier.

Glen, that sure is a nice job you did there. I hope that when I gather up some parts and tackle this project, I can get results as well constructed as yours and Thomas' are. I am going to have to try and avoid those damned $65 receptacles, and try to use more moderately priced parts. I don't aim to use $2.50 receptacles either, but I'm not going to be aiming for a no-hold-barred set-up like yours at this stage of the game. This build-up would simply be replacing what I currently have --> nada (or un-balanced).

Next Question: You've gone to the trouble (and benefit) of seperating your digital and analog devices. What exactly differentiates what you're classifying as digital or analog, and why? Does it have to do with the type of power supply on the device? Here's a sample list of items, what would each be, digital or analog (some are fairly obvious to me, others aren't):

Pre/Pro or Receiver
Amplifier
CD Player
DVD
DAC
Television
DLP Television
LCD Projector
Turn Table
Satellite Receiver
Tivo
Computer


BTW, Thanks for educating me.

[Ten 99]

Yet another Question

I forgot about this one till after I went back and read over it again.

What is the purpose of the GFCI's on this project? I get why we have GFCI circuits in the kitchen and the bathrooms, but why on this project? Is it going into a home theater that might be in a basement or something?

[ThomasW]

There are several things can add noise back into the AC lines, digital sources (DVD, CD players, DACs, etc) and anything that has a digital switching power supply. As a result it's a good idea to 'isolate' these types of devices.

Obviously the 'best' way to do this is with individual transformers for each device. That can get pretty expensive. A more cost effective option is to use a separate AC outlet with it's own RFI/EMI filter for each device. I'm currently working on a design like that. I'll be starting a new thread for it as the project progresses.

GFCI can be used anytime one wants the safety of having ground fault interrupt protection. Use of these units isn't just limited to circuits required by building code = kitchen/bath/laundry rooms/basement/etc.

[Glen B]

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[Ten 99]

Glen,

Thanks for that great explanation. The question came up before (by someone else) about why plugging a light into BP wasn't safe. Someone (can't remember who) gave the explanation about the neutral having a charge and changing bulbs not being safe as a result while powered by BP.

You're explanation about the GFCI and regarding the neutral wires really cleared up the question I had. Thanks again, and thanks for sharing your recipe and the pictures. They are very inspirational. I'm so happy that Thomas created this topic. It's something I've read about a few times here and there, but never got a whole lot of understanding from it. I have even read a fairly lengthy DIY how-to on building a balanced power setup, but in all honesty most of it was written above my head, and there was no one to bounce questions off of. I certainly wasn't going to justify spending $500+ on buying even the cheaper ones that I had seen, not really understanding the benefits or the needs. With the ability to get into this whole "Cheapskate" project relatively cheaply, and upgrading points where I want, it makes great sense to try it out.

By the way, thank all of you for breaking these technical mysteries down for regular guys like me. I know it can be hard to step outside of your own realm of knowledge, but some of us aren't top-notch engineers. I'm honored that we have these top-notch guys to help us out. It's a wonderful blessing. Especially for a dumb street-cop like me. :B I have forgotten more math and science than I can remember, and that's sad since I'm only 33 and can't recall much from the AP Calculus and Physics classes not THAT many years ago. In another thread, Thomas mentions how Jon has been doing speakers since 1969. Jon, don't take this the wrong way. That was the year before I was born. That doesn't make you old at all, only better. What's the saying? The older the violin, the sweeter the music.

[Hank]

Chris: good post, and drop the "dumb". We need good, ethical, moral cops on the "street" and I respect you. My son recently had a run-in with a cop with a "'tude". I think law enforcement, while a virtuous profession, unfortunately attracts latent bulleys (sp?).
This is all good stuff. :T

[ThomasW]

Chris,

Other than the base of a light bulb socket, I'm not aware of other electrical equipment used in HT that has an exposed 'neutral' .

I've been using non-GFCI balanced transformers for many years and have had no problems. But I know my gear, and keep it in tip-top condition. Also I never work on any piece of equipment that's plugged in. And if I need to check a circuit that's 'hot', it's plugged into a standard non-balanced line.

That being said if the potential 'shock' situation is a concern, then one should certainly add a GFCI to their balanced power unit.

In addition neither Glen's nor my units are using the special X2 type (self-clearing) caps for the differential noise filters on the AC outlets. This means that if the balanced power transformer passes a high voltage transient, the caps we're using will 'fuse' (short out) and must be replaced.

So if one wants to build a device with the highest level of safey, use a GFCI and X2 caps!

Finally if one wants to add a GFCI to an outlet in an existing balance power unit, there are inline devices available

[brucek]

Contact with the neutral side of the equipment and ground, whether deliberate or accidental, will expose the individual to 60V A.C. The situation is similar with lighting equipment. That is why operation of lighting equipment from balanced power is not recommended. The GFCI is for protection from shock

Generally I think you could say 'the situation is unique to lighting equipment', and this may well be sufficient reason to include GFCI. I can't really see any other safety issues associated with balanced power.

The safety ground is preserved in a balanced power unit, so any three prong device plugged in will have its case at safety and any keyed two prong device will be double insulated. I don't see a situation where anyone can come in contact with neutral unless they're inside their equipment with the unit plugged in (whether switched on or off) - and in that case whether using balanced or differential power they better be careful because there is power available inside.

Certainly lighting is an issue with the base of a bulb at 60volts, so for that situation the GFCI is wise.

Nice job on the unit Glen.. :T

brucek