A couple of years back, I used the following setup (for testing purposes only): Sine generator with XR2206 (diy
+ Quad 303 power amp (I had one in the basement!) + 220V/12V@5A mains transformer.
I hooked them up and powered a 60W/220V lamp. Output waveform seemed Ok, but with a heavier load, i.e. 150W, the small Quad was not enough to reach 220VAC.
I have no means for THD measurements but I'd say that as an experiment it was succesful.
+ Quad 303 power amp (I had one in the basement!) + 220V/12V@5A mains transformer.I hooked them up and powered a 60W/220V lamp. Output waveform seemed Ok, but with a heavier load, i.e. 150W, the small Quad was not enough to reach 220VAC.
I have no means for THD measurements but I'd say that as an experiment it was succesful.
--------------------------------------------------------------jcarr said:
Indeed very good. The Accuphase units are consistent in their effects. The PS Audio one (300) has not been consistent in my experience - I cannot prejudge the kind of effect it has and has had to modify the fan to silence the unit. Maybe the digital wave generator is the culprit.
analog_sa said:
Here's an even easier way of generating a low distortion sine-wave -- take a crystal controlled source, divide down to a 60Hz square wave -- apply the wave to a low pass filter -- you can use those from Maxim or Linear Tech, or even build a discrete design -- you can get a very inexpensive, amplitude stable sine wave with distortion below 0.01% -- I've done this with cascaded Linear Tech filters -- there is a residual amount of clocking noise in this approach, but it works. If you have to you can "pull" the crystal frequency a bit with a little capacitance.
<edit -- I should mention that Charles Hansen published a circuit in AudioXpress using this methodology -- he got the pin assignments wrong, so if you are reading the article, check out the manufacturer's data sheet before you wire it up!>
I've also used this with the Basic Stamp and PIC -- using the FREQOUT function in PICBasic Pro.
Decades ago we used "regenerated power" using a tube oscilator and a McIntosh amplifier to drive PLL circuitry -- but at a higher frequency than the line to get away from the 60Hz hum and harmonics.
I've been interested in this idea for a while, "power regeneration" does seem like a good idea to start with, but cost is, of course, a major issue - as previously mentioned most UPS aren't designed to filter mains of much noise - more likely that the cheap ones just remove spikes and protect (partially - given the battery life) from brown-outs.
Peter - have you actually tried 'scoping your UPS to see what it's outputting? - It might be enlightening for the followers of the thread (including my curious mind) to see the sort of "power regeneration" you're getting.
Peter - have you actually tried 'scoping your UPS to see what it's outputting? - It might be enlightening for the followers of the thread (including my curious mind) to see the sort of "power regeneration" you're getting.
Best deal Ive seen on a Best.
Peter,
Didn’t you say that you paid jus $30 CDN for that supply!
My gosh that’s a great deal. I haven’t yet been able to find the Fortress spec sheets, but that is a great little supply. Off hand id guess that the Sine output is in the 1% or less range, not too shabby at all. Having talked to engineers at Best a few times, I think one of the things that set this company apart from the commodity grade fire starter UPS products, is that these guys really care about building a good product that does what the customer thinks it does.
A lot of the best product line (I dont think its just the FerrUps) use ferro-resonant boost buck transformers on the input. Its a great way of providing some line regulation and isolation at the same time.
Ive often pondered more about taking an old UPS and modding it to be an amplitude follower for a Sub woofer. I figure its not likely that I could hope to get 20 KHz response out of something designed to oscillate at 60 Hz.
Are there any more where that more came from? Its a great deal, even if it needs new cells.
There used to be a trick used by recording studios to run a tape machine like an Ampex 440 off speed. This was back in the steam driven days of audio. An oscillator and a 50 watt McIntosh amplifier would be coupled together to drive the Bodine synchronous capstan motor. Wiggle the auscultator off 60 Hz (that’s 50 Hz every where it isn’t 60) and viola that machine would run off pitch! I've always wondered if the first guy to try this new anything of the impedance of the motor or if he just blissfully jumped in.
Peter,
Didn’t you say that you paid jus $30 CDN for that supply!
My gosh that’s a great deal. I haven’t yet been able to find the Fortress spec sheets, but that is a great little supply. Off hand id guess that the Sine output is in the 1% or less range, not too shabby at all. Having talked to engineers at Best a few times, I think one of the things that set this company apart from the commodity grade fire starter UPS products, is that these guys really care about building a good product that does what the customer thinks it does.
A lot of the best product line (I dont think its just the FerrUps) use ferro-resonant boost buck transformers on the input. Its a great way of providing some line regulation and isolation at the same time.
Ive often pondered more about taking an old UPS and modding it to be an amplitude follower for a Sub woofer. I figure its not likely that I could hope to get 20 KHz response out of something designed to oscillate at 60 Hz.
Are there any more where that more came from? Its a great deal, even if it needs new cells.
There used to be a trick used by recording studios to run a tape machine like an Ampex 440 off speed. This was back in the steam driven days of audio. An oscillator and a 50 watt McIntosh amplifier would be coupled together to drive the Bodine synchronous capstan motor. Wiggle the auscultator off 60 Hz (that’s 50 Hz every where it isn’t 60) and viola that machine would run off pitch! I've always wondered if the first guy to try this new anything of the impedance of the motor or if he just blissfully jumped in.
Attachments
Hi,
It's interesting to speculate how the UPS designer's get a nice sine-wave, since few will dicslose their schematics.
For me, many years ago, I was asked to design a turntable power supply, capable of 25 watts.
As stated in the original thread, I will not divulge the power circuitry (since it does not provide mains isolation), but am happy to show the sinewave generation mechanism.
Of course in retrospect, I can think of better ways of doing it, but this one is proven and tested.
No doubt it will be subject to critisism, but who cares?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=8118&highlight=crystal
and
http://www.dhaen.org.uk/vdocs/PHsch_ref.gif
Cheers,
It's interesting to speculate how the UPS designer's get a nice sine-wave, since few will dicslose their schematics.
For me, many years ago, I was asked to design a turntable power supply, capable of 25 watts.
As stated in the original thread, I will not divulge the power circuitry (since it does not provide mains isolation), but am happy to show the sinewave generation mechanism.
Of course in retrospect, I can think of better ways of doing it, but this one is proven and tested.
No doubt it will be subject to critisism, but who cares?
http://www.diyaudio.com/forums/showthread.php?s=&threadid=8118&highlight=crystal
and
http://www.dhaen.org.uk/vdocs/PHsch_ref.gif
Cheers,
I will try to explain one more time.......
When you look at a line filter are UPS ask yourself the following:
Is the inverter runnig all the time and what kind of noise is that putting in the unit even in the AC input mode?
What is the unit doing to the AC wall voltage as it passes through it? Does it contain RF filters, isolation transformers, digital circuitry being power by the unit?
How does it do the transistion between the UPS and normal AC mode?
I am not bring all this up to be a smart ***. The Tripp Lite line condition was a big fad a few years ago. A couple of my friends bought one and guess what? They sounded bad! Being a curious sort of guy, I analysed and modified one. Changed out the ceramic caps, lost the captive line cord an put an IEC connector on the box, and hard wired the internal wiring instead of those awful spade terminals. There has been disscusion of things like capacitor bypassing fuse holders on the forum and I seem to remember Mr. Carr polishing AC plugs in Stereophile awhile back. I have been messing AC stuff for over 15 years. Jocko add I used the first specialty line cords from Tiffany over 15 years ago and nearly scatch holes in our heads as to why they sounded better. I respect you interest in the subject but have about a decade and a half head start. I will gladly shut up on the subject though, if it of little interest.
I will not spend several weeks of arguing with people who know nothing about the subject, as so often occures on this forum. They is plenty of information on the subject out there. Like I keep saying, do the research.
When you look at a line filter are UPS ask yourself the following:
Is the inverter runnig all the time and what kind of noise is that putting in the unit even in the AC input mode?
What is the unit doing to the AC wall voltage as it passes through it? Does it contain RF filters, isolation transformers, digital circuitry being power by the unit?
How does it do the transistion between the UPS and normal AC mode?
I am not bring all this up to be a smart ***. The Tripp Lite line condition was a big fad a few years ago. A couple of my friends bought one and guess what? They sounded bad! Being a curious sort of guy, I analysed and modified one. Changed out the ceramic caps, lost the captive line cord an put an IEC connector on the box, and hard wired the internal wiring instead of those awful spade terminals. There has been disscusion of things like capacitor bypassing fuse holders on the forum and I seem to remember Mr. Carr polishing AC plugs in Stereophile awhile back. I have been messing AC stuff for over 15 years. Jocko add I used the first specialty line cords from Tiffany over 15 years ago and nearly scatch holes in our heads as to why they sounded better. I respect you interest in the subject but have about a decade and a half head start. I will gladly shut up on the subject though, if it of little interest.
I will not spend several weeks of arguing with people who know nothing about the subject, as so often occures on this forum. They is plenty of information on the subject out there. Like I keep saying, do the research.
Criticism
Criticism is fine, that's why we have design reviews in the real engineering world. It is the arguments with people with no experience or real knowledge in the subject. The very same people who feel perfectly conformable telling someone with 10 years of work in a given subject, that it don't matter or that they are wrong. What was the term for this class of people?............ oh yes I remember, idiots.
dhaen said:
Criticism is fine, that's why we have design reviews in the real engineering world. It is the arguments with people with no experience or real knowledge in the subject. The very same people who feel perfectly conformable telling someone with 10 years of work in a given subject, that it don't matter or that they are wrong. What was the term for this class of people?............ oh yes I remember, idiots.
Re: I will try to explain one more time.......
I know that you won't and I value your opinion, but I also won't accept your constant nagging about doing my own R&D (because I do them). If you have any objections, we can discuss it privately.
I was also curious about the above questions, mainly if the AC signal is regenerated when the UPS runs from AC. I would suspect that it shouldn't, but frankly, I don't know. But it certainly improves the sonics, no matter how it's run.
What I noticed today measuring the signal is that a AC supply directly from a wall improved the moment I connected the UPS to wall outlet. But the improvement wasn't as big as the one from UPS.
Fred Dieckmann said:
I know that you won't and I value your opinion, but I also won't accept your constant nagging about doing my own R&D (because I do them). If you have any objections, we can discuss it privately.
I was also curious about the above questions, mainly if the AC signal is regenerated when the UPS runs from AC. I would suspect that it shouldn't, but frankly, I don't know. But it certainly improves the sonics, no matter how it's run.
What I noticed today measuring the signal is that a AC supply directly from a wall improved the moment I connected the UPS to wall outlet. But the improvement wasn't as big as the one from UPS.
Re: I will try to explain one more time.......
And what are you talking about here? I have a unit, which clearly improves the AC power line and it can be detected both subjectively and objectively, I'm happy with the device and I share my view on that, on a forum.
So why are you asking me to do the research for? I don't intend to pursue it any further as I don't see a need for that. So what, it annoys you now as well?
Do your own research if it makes you happy.
Fred Dieckmann said:
And what are you talking about here? I have a unit, which clearly improves the AC power line and it can be detected both subjectively and objectively, I'm happy with the device and I share my view on that, on a forum.
So why are you asking me to do the research for? I don't intend to pursue it any further as I don't see a need for that. So what, it annoys you now as well?
Do your own research if it makes you happy.
Re: I will try to explain one more time.......
Fred,
we knew that you knew, no need to keep slapping your pluriennial experience in the field and your EE degree in every single post of yours, it's becoming counter productive to your cause and making you look like a little frustated psycho monkey.
It hurts to say it, but if you limit your contributions to this kind of level you might has well just go reorganize your listening room and box up some of your creations that desperately need it.
I am sure everyone here would be delighted to hear from you on how to put together a compliant audiophile grade UPS. If that's private info you don't want to divulge that's too bad, I am sure you'll be able to use your knowledge in your next life.
Fred Dieckmann said:
Fred,
we knew that you knew, no need to keep slapping your pluriennial experience in the field and your EE degree in every single post of yours, it's becoming counter productive to your cause and making you look like a little frustated psycho monkey.
It hurts to say it, but if you limit your contributions to this kind of level you might has well just go reorganize your listening room and box up some of your creations that desperately need it.
I am sure everyone here would be delighted to hear from you on how to put together a compliant audiophile grade UPS. If that's private info you don't want to divulge that's too bad, I am sure you'll be able to use your knowledge in your next life.
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