Anyone Build a Power Regenerator?

[gfle]

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.

[fmak]

Originally posted by jcarr
A somewhat different and (hopefully) cooler and more efficient approach is mentioned here:

http://db.audioasylum.com/scripts/t....neral&m=279286

hth, jonathan carr

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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.

[jackinnj]

Originally posted by analog_sa
Amusingly i followed almost exactly the steps described by Martin.

1) I did an AVR-DAC_lopass thing which synthesised a very passable 50Hz out of a 100 point lookup table. Not sure now, but definitely bellow 0.1% thd. The microcontroller route is good as it allows the generation of all sorts of 'multiwaves'

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.

[annex666]

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 Daniel]

I'll check it out today.

[Da5id4Vz]

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 Daniel]

I got 2 of them and I paid CAD50 for ea. with new Panasonic cells. I'll be going there today to see if they have more

Here're my measurements. This is AC wave directly from a wall:

[Peter Daniel]

That's the same coming through my UPS (when it runs from AC power):

[Peter Daniel]

This is AC line when UPS runs from batteries:

[Peter Daniel]

That's better view of AC power from the UPS: