homemade power conditioner?

[Joe]

I am in need of a power conditioner for my home recording studio. I was
wondering if I could use some of the components I already have. I want to
run my equipment off of an inverter, which would be connected to a 12volt
battery, which would be constantly charged by a battery charger. Has anyone
done this? Is it a logical way to get clean power?

 

[John Popelish]

I am in need of a power conditioner for my home recording studio. I was
wondering if I could use some of the components I already have. I want to
run my equipment off of an inverter, which would be connected to a 12volt
battery, which would be constantly charged by a battery charger. Has anyone
done this? Is it a logical way to get clean power?

Probably not. The most important factor for an audio setup is that
the line waveform have little high frequency distortion that might
bleed through to audio signals and also a good, clean ground. The
exact magnitude of line voltage is not very important. A good line
filter or shielded isolation transformer with a clean downstream
ground might be nice.

A regulating transformer (Sola ferroresonant) might be good upstream
of AC motor driven devices like tape drives and turn tables. But good
quality motor driven devices do not depend on the line frequency or
voltage, anyway.

Inverters generally make high frequency noise that gets into signals
and grounds.

 

[exray]

I am in need of a power conditioner for my home recording studio. I was
wondering if I could use some of the components I already have. I want to
run my equipment off of an inverter, which would be connected to a 12volt
battery, which would be constantly charged by a battery charger. Has anyone
done this? Is it a logical way to get clean power?

Yikes! Unless the inverter has some excellent conditioning built in
thats a VERY bad way to get power. The inverter output is full of
spikes and the waveform will be poor.
The best bang for the buck would be an old Sola type constant voltage
transformer. No electronic components, no moving parts, good isolation,
waveform will be good enough for modern electonics, etc. Big and heavy
but no so much compared to a 12 volt battery and inverter.
An outfit in Chicago? called Shape Electronics is a major manufacturer
of these nowadays. You'd be hard pressed to damage one with a surge or
have a spike get thru it.

-Bill

 

[CJT]

Yikes! Unless the inverter has some excellent conditioning built in
thats a VERY bad way to get power.

That's how some UPSs work.

The inverter output is full of

spikes and the waveform will be poor.

You can't tell without details. Some are excellent, and others are
poor. There may be a correlation with price.

 

[John Walton]

Occasionally you will see Hewlett Packard (or now Agilent) A.C. power
supplies on EBay -- there is a separate power supply section under test
equipment.

When I was in college we powered some of the "quiet room" physics equipment
from an a.c. line which was driven by a MacIntosh tube amplifier. This gave
a very quiet and regulated sine wave to drive some of the instrumentation.

 

[exray]

That's how some UPSs work.
Exactly.

The inverter output is full of



You can't tell without details. Some are excellent, and others are
poor. There may be a correlation with price.

No question about it. The OP was aking about homebrewing and if that
was a logical approach.

I'd stick with the constant voltage transformer.

-Bill M

 

[Scott Dorsey]

I am in need of a power conditioner for my home recording studio. I was
wondering if I could use some of the components I already have. I want to
run my equipment off of an inverter, which would be connected to a 12volt
battery, which would be constantly charged by a battery charger. Has anyone
done this? Is it a logical way to get clean power?

Why do you need a power conditioner? What is the problem you are trying
to solve?

Most inverters will produce MUCH worse waveforms than the power line, and
you will have bigtime noise issues trying to run off of them. You can get
some true sine wave inverters that have very low distortion, but they are
not cheap or efficient.
--scott

 

[[email protected]]

| In article <[email protected]>,
|>I am in need of a power conditioner for my home recording studio. I was
|>wondering if I could use some of the components I already have. I want to
|>run my equipment off of an inverter, which would be connected to a 12volt
|>battery, which would be constantly charged by a battery charger. Has anyone
|>done this? Is it a logical way to get clean power?
|
| Why do you need a power conditioner? What is the problem you are trying
| to solve?
|
| Most inverters will produce MUCH worse waveforms than the power line, and
| you will have bigtime noise issues trying to run off of them. You can get
| some true sine wave inverters that have very low distortion, but they are
| not cheap or efficient.

What would you recommend to get a nice clean pure sine wave, with no spikes
or other high frequency hash, and is also locked tight to a frequency standard
(unlike the utility power which has the liberty to tweak the frequency when
demand is too high). This will need to also have backup capability, which
might be for an extended period of time, which means a generator may be the
source of power at times.

Note: I'm not the original poster of this thread, but I have a similar
interest.

 

[Todd H.]

Inverters generally make high frequency noise that gets into signals
and grounds.

Amen.

Glad to hear this mentioned because not 10 seconds ago, I unplugged my
laptop computer power to get rid of the annoying high pitched
beeping-like subtle noise that I finally isolated as a ground loop
that was coming through my computer speakers.

My computer speakers are plugged into the wall and take 2 inputs--one
from my PC running off an APC Back Ups Pro UPS, and the other from the
laptop which is plugged into the wall. While plugging all 3 in the
UPS doesn't seem to fix it (likely due to a peripheral hanging off the
PC plugged into the wall), unplugging either one of the PC's audio to
the speakers fixes it, or unplugging power from the laptop does the
trick too.

Anyone know of any place selling 1/8" stereo inline isolation
transformers?

Best Regards,

 

[Watson A.Name \Watt Sun - the Dark Remover\]

Glad to hear this mentioned because not 10 seconds ago, I unplugged my
laptop computer power to get rid of the annoying high pitched
beeping-like subtle noise that I finally isolated as a ground loop
that was coming through my computer speakers.

My computer speakers are plugged into the wall and take 2 inputs--one
from my PC running off an APC Back Ups Pro UPS, and the other from the
laptop which is plugged into the wall. While plugging all 3 in the
UPS doesn't seem to fix it (likely due to a peripheral hanging off the
PC plugged into the wall), unplugging either one of the PC's audio to
the speakers fixes it, or unplugging power from the laptop does the
trick too.

Anyone know of any place selling 1/8" stereo inline isolation
transformers?

Well, Radio Scrap has (or had) an isolation transformer for auto apps,
which should also work in this case. But it seems to me that it would
be better to isolate the actual noise, which might be coming from the
wall wart or power brick that charges your laptop battery.

You might try putting a big electrolytic, like a 4700 uF, across the
power from the batt charger. Just to see what happens.

 

[Scott Dorsey]

What would you recommend to get a nice clean pure sine wave, with no spikes
or other high frequency hash, and is also locked tight to a frequency standard
(unlike the utility power which has the liberty to tweak the frequency when
demand is too high). This will need to also have backup capability, which
might be for an extended period of time, which means a generator may be the
source of power at times.

What kind of load, and why do you need frequency stability? For most
equipment, frequency stability is a non-issue.

I can recommend the Best and Liebert online UPS systems. The 12KVA and
larger units can be slaved to an external reference oscillator if you
really need stability, and they can be specified to under 2% line distortion.
The Invensys BPIII Industrial is a good choice if you need more than 100 KVA.

If you need better than 2% distortion and only have small loads, Abacus
Controls, KGS Electronics, and Industrial Test Equipment, Inc. all make
stabilized AC supplies. Count on closer to $10/watt, though, as opposed
to around $1/watt for the cheaper Best and Liebert gear.

We replaced our 400 Hz motor-generator set systems with a bunch of the
smaller Abacus Controls boxes, and they are phenomenally more convenient.
No poking, no prodding, no calling down to the basement to fire the converter
up in the morning.
--scott

 

[William P.N. Smith]

What would you recommend to get a nice clean pure sine wave, with no spikes
or other high frequency hash, and is also locked tight to a frequency standard
(unlike the utility power which has the liberty to tweak the frequency when
demand is too high). This will need to also have backup capability, which
might be for an extended period of time, which means a generator may be the
source of power at times.

Note: I'm not the original poster of this thread, but I have a similar
interest.

Wow, that's a lot of requirements, I'd revisit them first to see if
what I was trying to do could be done in a more economical fashion.
In a brute-force kinda world, you'd end up with one of the HP AC
sources that John was talking about, running off a separate UPS, with
a backup generator, but that's a whole ton of money compared to (for
instance) running your device off batteries and using a real frequency
standard for the parts that care about that.

 

[William P.N. Smith]

Anyone know of any place selling 1/8" stereo inline isolation
transformers?

WalMart has them for cars, so you'll need Phono-to-headphone adapters.
Worked wonders for fixing the ground loop problem my iPod had with my
AUX input in my car...

 

[Monte P McGuire]

I am in need of a power conditioner for my home recording studio. I was
wondering if I could use some of the components I already have. I want to
run my equipment off of an inverter, which would be connected to a 12volt
battery, which would be constantly charged by a battery charger. Has anyone
done this? Is it a logical way to get clean power?

This sounds like a great waste of energy, both human and electrical.
Is your AC line really that bad? Professional audio equipment works
just fine with normal power company AC power.

The only thing I'd recommend is using a UPS if you'll operate a DAW
and you don't want to deal with short outages and glitches. The APC
SmartUPS sine wave output models are pretty good for this use. I bill
out time on my rig, and having a UPS prevents downtime, which saves
everyone.

Aside from that, the power conditioning setup you describe sounds like
a potentially dangerous, expensive waste of time, energy and money.
Unless of course, you have some real problem with utility power that
I'd be interested in hearing about so we can suggest a workable
solution.


Regards,

Monte McGuire
[email protected]

 

[Watson A.Name \Watt Sun - the Dark Remover\]

What kind of load, and why do you need frequency stability? For most
equipment, frequency stability is a non-issue.

I can recommend the Best and Liebert online UPS systems. The 12KVA and
larger units can be slaved to an external reference oscillator if you
really need stability, and they can be specified to under 2% line distortion.
The Invensys BPIII Industrial is a good choice if you need more than 100 KVA.

If you need better than 2% distortion and only have small loads, Abacus
Controls, KGS Electronics, and Industrial Test Equipment, Inc. all make
stabilized AC supplies. Count on closer to $10/watt, though, as opposed
to around $1/watt for the cheaper Best and Liebert gear.

We replaced our 400 Hz motor-generator set systems with a bunch of the
smaller Abacus Controls boxes, and they are phenomenally more convenient.
No poking, no prodding, no calling down to the basement to fire the converter
up in the morning.
--scott

We had a 80kVA Exide UPS for our computer room, then replaced it with a
150kVA Exide, that we have today.

We need to get a couple 2 to 3 kVA UPSes for some PBXes, and we've been
using Fortress and APCs lately. Are there any better UPSes out there?
The PBX uses a ferroresonant transformer in the constant voltage 48VDC
PS. If that makes any diff.

 

[Arny Krueger]

I am in need of a power conditioner for my home recording studio. I
was wondering if I could use some of the components I already have.
I want to run my equipment off of an inverter, which would be
connected to a 12volt battery, which would be constantly charged by a
battery charger. Has anyone done this? Is it a logical way to get
clean power?

First make sure that you have bad power. This device will give you a number
of objective clues:

http://www.smarthome.com/9034.html

 

[Kurt Albershardt]

What would you recommend to get a nice clean pure sine wave, with no spikes
or other high frequency hash, and is also locked tight to a frequency standard
(unlike the utility power which has the liberty to tweak the frequency when
demand is too high). This will need to also have backup capability, which
might be for an extended period of time, which means a generator may be the
source of power at times.

With the frequency requirement, you're basically looking at a double conversion online UPS--whether prepackaged or soemthing you piece together.

Toshiba makes excellent medium-sized UPSs with low distortion output http://www.tic.toshiba.com/productgroups.php?family=UPS
Oneac makes smaller units that are also very clean http://www.oneac.com/pdf/917161b1.pdf

Exeltech makes low distortion inverters as small as 125 Watts and for a wide range of DC inputs http://www.exeltech.com/ If you need very long runtime, it can be much cheaper to build your own solution with telecom batteries and charging plus one of these.

 

[Kurt Albershardt]

The only thing I'd recommend is using a UPS if you'll operate a DAW
and you don't want to deal with short outages and glitches. The APC
SmartUPS sine wave output models are pretty good for this use. I bill
out time on my rig, and having a UPS prevents downtime, which saves
everyone.

They do the job and at a very reasonable price, but their output waveform is still pretty noisy. Stick a 'scope across the line and yank the plug sometime...

Best and Oneac both make small UPSes with clean outputs.

 

[Scott Dorsey]

We had a 80kVA Exide UPS for our computer room, then replaced it with a
150kVA Exide, that we have today.

We need to get a couple 2 to 3 kVA UPSes for some PBXes, and we've been
using Fortress and APCs lately. Are there any better UPSes out there?
The PBX uses a ferroresonant transformer in the constant voltage 48VDC
PS. If that makes any diff.

If you have a ferroresonant transformer there, you don't really need a good
waveform on the input, but you do need pretty good frequency regulation.
You can also live with dropouts as a result, too, so you can probably get
away with a cheaper standby UPS without any trouble.

Somebody has nicked the BEST catalogue from my office and I don't remember
the name of their line of cheap standby UPS systems without isolation.
It's one line below the Ferrups stuff. I think that's about where you should
be looking because it's no sense spending money for capability you don't need.
You should make sure that it will be happy driving the ferroresonant
transformer, though, which will be a weird load. Get the power factor off
the PBX supply and make sure the UPS is reated for it.

I've had some bad experiences with the APC stuff and had some trouble
getting APC to make good on their guarantees.

Most of the other stuff I am familiar with are online systems, which you
really don't need.

Have you considered just floating a 48V battery off the rails? It would
seem a lot cheaper to just provide the battery backup on the 48V side
rather than on the AC input. You might want to check Power Conversion
Products at www.pcp.com for telco power stuff.
--scott

 

[Kurt Albershardt]

We need to get a couple 2 to 3 kVA UPSes for some PBXes, and we've been
using Fortress and APCs lately. Are there any better UPSes out there?
The PBX uses a ferroresonant transformer in the constant voltage 48VDC
PS. If that makes any diff.

With the FRT, you won't need super-low distortion AC and you won't need zero-dropout switching, so a standby UPS would probably work fine.

Why not just replace or augment the -48V system with something bigger & newer? You wouldn't believe how much -48V overstock and surplus stuff out there from the dotbomb & telecom busts.

Where are you located? I can probably find you a turnkey solution from a bonded vendor if you want...