# modified or true sine?



## patarini (Nov 19, 2004)

I currently use a 3000 watt modified inverter from my semi for the house, is there any valid reason to change to a true sine? I run everything I want so far, and dont want to use the money for that -- rather get more panels and a wind gen or 2 for those dark stormy nights!


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## wy_white_wolf (Oct 14, 2004)

If eveything you want runs fine on it. Nope


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## Jim-mi (May 15, 2002)

There is a bunch of stuff that won't run well on mod sign. I think its the Makita(sp) cordless drill battery chargers that will smoke (burn out) when pluged into mod sign.
Motors will run much hotter on mod sign thereby shortning there life.
I could go into a fairly long list of the negative's of mod sign.........But----if what you have runs ok then go for it.

But save your bucks cause sooner or later you'll want to upgrade to sign wave


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## greg273 (Aug 5, 2003)

I've heard that about Makita's... but I know that my DeWalt 14volt battery charger works just fine on the el-cheapo 600watt inverter I'm currently using. I just hope it continues to work when I get the DR2424 up and running.
I have noticed one of my box fans runs louder when using the inverter.


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## MELOC (Sep 26, 2005)

you can buy a "power cleaner" like are used for computer usage for those sensitive devices. many have battery back-up. what is the term for those...uninteruptible power supply? whatever the terminology, they usually provide surge protection, convert from modified to true sine wave and often have battery back-up. they come in many wattage sizes.


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## patarini (Nov 19, 2004)

Never thought of that -- thnx for the great idea!


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## ET1 SS (Oct 22, 2005)

An isolation transformer will smooth out the spikes too.


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## Weho Dave (May 21, 2006)

I have read that electric motors will run more efficiently on a pure sine inverter. Also some electronics require pure sine for correct clock cycling, such as computers, timers, etc. But if what you have is working then don't fix it.


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## ET1 SS (Oct 22, 2005)

It is not a matter of efficeincy so much as heat. The sharp edges of a square wave will cause heat to build up. Whereas the smoothed out waves of a nice sine-wave do not build up as much heat.


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## Jim-mi (May 15, 2002)

There is NO "converter" to go from mod sign to true sign wave.

Those $50 "uninterruptible" power supplys are mod sign.
They will keep your puter and or your phone answering machine from an abrupt crash............for a short while.
The one I had, the battery went south within two years.


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## mightybooboo (Feb 10, 2004)

MELOC said:


> you can buy a "power cleaner" like are used for computer usage for those sensitive devices. many have battery back-up. what is the term for those...uninteruptible power supply? whatever the terminology, they usually provide surge protection, convert from modified to true sine wave and often have battery back-up. they come in many wattage sizes.


Do you have some links?My understanding is most UPS have very dirty mod sine wave power,would like to see some pure sine wave ones.

I havent seen anything to date that equates a 'pure' sine wave to inexpensive,closest being the samlex like Tango has.

And desktops can run on some pretty dirty power too powering that power supply inside the box.

BooBoo


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## ET1 SS (Oct 22, 2005)

Running through any inductor will change the wave-form.

A coil will some, a 60-hertz tank-circuit will, better yet an iso-transformer will knock-out those pesky sharps edges and corners.

As for a battery lasting 2-years, compared to it's 3-year expected life-cycle 2-years is not bad. And way better than it's 90-day warranty.


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## ET1 SS (Oct 22, 2005)

mightybooboo said:


> Do you have some links?My understanding is most UPS have very dirty mod sine wave power,would like to see some pure sine wave ones.
> 
> I havent seen anything to date that equates a 'pure' sine wave to inexpensive,closest being the samlex like Tango has.


True, not built from IC chips.



> And desktops can run on some pretty dirty power too powering that power supply inside the box.
> 
> BooBoo


Anything that says it's input requirements are: 50-60Hz, 110-220 VAC. and it only has to output +12VDC, -12VDC, +5VDC, -5VDC; it is not like it really needs anything special for input.

LOL


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## Jim-mi (May 15, 2002)

LOL.......Ok who (except you and I ) has an iso xformer laying around..........??

The point I would make is; Why in this day and age even use mod sign when there is many good sign inverters out there.

Everything runs better on sign wave..........it was designed to.

The mod sign came about as a more reasonablely priced inverter option. For quite some while it served well. But times have changed. Now there is many sign's to choose from for not that much more $$$.

yes Et...heat is the motors enemy.......


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## MELOC (Sep 26, 2005)

mightybooboo said:


> Do you have some links?My understanding is most UPS have very dirty mod sine wave power,would like to see some pure sine wave ones.
> 
> I havent seen anything to date that equates a 'pure' sine wave to inexpensive,closest being the samlex like Tango has.
> 
> ...



like this?

http://www.opti-ups.com/ups_detail.phtml?product_id=33


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## mightybooboo (Feb 10, 2004)

MELOC said:


> like this?
> 
> http://www.opti-ups.com/ups_detail.phtml?product_id=33


That would work,cool and thanks!I havent seen any pure sine wave backups,and at 200 bucks for 600 watts,thats not bad.

Some questions.

See page 10 of the manual on the link.

The power goes from ac wall outlet to an emi/ra noisefilter through the conditioner(adjusts for low/high voltage) the transfer switch to load.Is the emi/ra noisefilter a sinewave modifier for square waves?

Next function is ac wall to charger to battery.Should power fail,the microprocessor then alerts battery to send power to inverter that makes sine wave output,through transfer switch and to load.

I dont see where it is actually sending any load through inverter and UPS sinewave output unless ac power has failed.In other words,I dont see where it actually cleans up square wave input fed in from power source ac,only produces sine wave when ac is off.Other wise it just allows the ac from wall to pass through.
You may be able to charge its battery with mod sine wave(maybe,I dont know if the UPS will operate on mod sine wave) then unplug it and get sine wave out,but with ac connected all it does is pass power through,albiet filtering some noise and adjusting voltage variances.

BooBoo


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## zant (Dec 1, 2005)

Ran my offgrid home for 7yrs on Trace sine wave inverter.They are much cheaper now.Try sunelec.com-4000SW for 1800.00....It's always amazed me how cheap alt energy users are...Spend the money for quality...


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## Jim-mi (May 15, 2002)

Yup

Some folks are hard to convince.


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## MELOC (Sep 26, 2005)

mightybooboo said:


> That would work,cool and thanks!I havent seen any pure sine wave backups,and at 200 bucks for 600 watts,thats not bad.
> 
> Some questions.
> 
> ...



well...if that is true that is deceiving as hell. i thought it could be an economical add on instead of total replacement for someone needing true sine wave for a small load. perhaps not.

edit...

the more i think about it, the less i understand why someone would make such a device if it only delivers true sine wave during back-up power. why would that even be needed and how often utilized? very strange for a company to manufacture such a device...


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## MELOC (Sep 26, 2005)

since i feel scolded and i feel duped, i searched the web some and found a company called leonics. i think they make true sine ups but i imagine they are not cheap and are intended for "industrial" use and not for the consumer market. the only way to get a price is to request a quote from the company.


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## Jim-mi (May 15, 2002)

A 'sign wave modifier for square waves'

a bit of double speak.

buyer beware.

Yes MELOC a real UPS is very expensive.

The $50 one (I had ) is barely a step above junk.
And I hate to admit it, I think I got it at wally unsmarts.
Yes that was before I knew better (about wallys unsmarts)


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## ET1 SS (Oct 22, 2005)

"a sign wave modifier for square waves"

Just about anything will modify a square wave.


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## tsdave (Nov 3, 2002)

I have a elcheapo 300 watt inverter from before y2k. Had a 100 watt before it, but it blew up. Heres what i know of inverters.

Modified sine are/were more efficient than pure sine, like 5-10%. ~1999 
In modified sine there are numbers of steps, going from square to bunches of steps,
and probably sine inverters use a WHOLE bunch of steps and then smooth them out.
IE there could be better quality mod signs due to steps used.

In addition to making motors get hotter, mod sine will make motor louder and slower.
or at least i notice fans blow less air on an inverter.

I have never had any item 'blow up' from using modified sine, but i guess its possible.

And as far as i know, all but the most expensive UPS only run the inverter when the power fails (otherwise it would be wasting ~10% in heat all the time) and most are modified sine. But some of the REALLY expensive do provide filtered power off the inverter 100% of the time, but they are for commercial use, like important database servers, or routers, etc.

My plan back in y2k was to use a small pure sine and a large mod sine. But i never got the pure sine. To run the picky loads (or quieter) on the small one, but have the redundency and utility of two different inverters.


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## Kenneth in NC (Nov 20, 2002)

The best place I knowof to buy a "UPS" is a hamfest. There usually about $3-800 and come with 90 day warranty. Now if your "electrical minded" I have seen them for $150-200 out of office complexes. Might need a new battery or minor cleaning/repair.

Largest Hamfest in NC "SHELBY HAMFEST" Coming up early part September (Labor Day week-end I believe). If your in the neighborhood give a shout I'm not far from where they hold it. 

Kenneth


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## Jim-mi (May 15, 2002)

Put a scope on a Trace\Zantrex 4024 and you will see 56 steps.
Not bad for the time, but since that came out others are now better.

If you really want to heat up a motor try running it on the old square wave inverters.


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## mightybooboo (Feb 10, 2004)

say Jimmi,along that line,what do the other sine waves look like,do you know offhand?

thanks,

BooBoo


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## Jim-mi (May 15, 2002)

No I haven't seen\done a comparison of the newer sine wave inverters.
The Outback products have many more steps than the Zantrex.
But by far the cleanest one is the Exeltec.

In defence of the ole Zantrex 4024, even their multi steped 'sine wave' makes most all equipment far happier than when it is run on mod sign.


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