Pure (True) vs. Modified Sine Wave?

[Ireland-or-bust]

I'm hoping soon to get my A. Lights (CFLs) and B. My heating circulator
off grid.

I only have a modified sine wave inverter and i am told this is not good for CFLs.

Has anyone tried this? What happened?
The pure inverters are mega bucks and if possible i'd like not to buy one.

Ideas & inovations accepted.

Mark

[John Headstrong]

I have tested a modified sine wave inverter with CFL blubs and they buzz a little. not mega loud, but noticeable up close from what I remember (it was ages ago and memory is not great these days )

I will dig it out later and give it another test see just how loud it is.

edited to add: it is a cheap maplins 600w invertor for £30

[Brod]

Bought a cheap 150 watt invertor from LIDL and it would only run the very small 11 watt (60 watt equivilent) CFL anything bigger wouldn't light up (very loud buzzing but no light).

Also bought one of the 600 watt invertors from maplin when it was on special offer, that runs small and large CFL's and also the traditional 5 foot floresent tubes as well.

IIRC both were labelled modified sine wave. my electronic inclined mate says that not all modified sine wave are equal, you get what you pay for (ie the more you pay the closer they come to pure sine waves).

p.s. SiteGeek, I can hear CFL buzzing on mains, very quiet but out in the sticks you can hear them. Some brands will buzz slightly louder using the invertor but it depends on the make.

[Ireland-or-bust]

Latest,

Well my 300w modified is on its way out having never seen the light of day.

I asked an electrician friend and he said "anything the buzzes when you put current through it is dying a slow death."

So i bought a fine Pure sine wave inverter from ebay second hand (not used tho) for £122.

Its a nice 1Kw one with 2Kw surge. Should run all sorts.

Thanks anyway.
Mark

[Turtuga Blanku]

on a somewhat related subject: modified sine wave inverters disturb your CRT-monitor: lines going along the screen. No big deal, just thought I'd mention it.

[Ireland-or-bust]

Hi,

Is that only CRTs? or does that include TFTs too?

Mark

[Turtuga Blanku]

nope! Only CRTs, as far as I know.

[ENIGMA]

Hi,doe's anyone know if I can run a well pump of a modified sine wave inverter,without it harming the pumps motor?

[Odsox]

Can anyone tell me if you can run laptops from 12v DC or do they need an inverter ?
I have 3 PCs, sometimes all running at the same time and they use quite a bit of mains power.

[Clara]

Hi,doe's anyone know if I can run a well pump of a modified sine wave inverter,without it harming the pumps motor?

I´m not an expert, but I remember being told that MSW invertors often have problems with the water pump on washing machine.

When I replaced my old PV system, we bought a MSW invertor, it was all of 2 days before I called the installation company and told them I wanted to upgrade.......washing machine wouldn´t work, laptop charger blew, constant buzzing of everything.

[ENIGMA]

Thanks Clara,
These MSW inverters seem to have as much use as a "chocolate teapot".I wonder if anyone has had any success with them? Shouldn't they carry a warning,that they may seriously damaged ones appliances?

Odsox,I was thinking along the same lines as you,concerning running laptops of a 12v dc supply.Well if you are lucky enough to have a 12v laptop then you can but most laptops are more then that .I have seen a device at http://www.maplin.com which gives a variable voltage for most laptops from a 12v dc supply.It's on special at the moment for 19.99 pound.

I would certainly look into this option if and when I buy a laptop.

[Odsox]

Thanks for that Enigma.
I have never owned a laptop but had a sneaky suspicion that they ran on 18 volts or something strange.
It weird as most of the parts in an ordinary PC are either 12 volts or 5 volts, so why it's higher for a portable device escapes me at the moment.

[John Headstrong]

I have used one of these for laptops on 12v

http://tinyurl.com/5c3q59

[Clara]

Thanks Clara,
These MSW inverters seem to have as much use as a "chocolate teapot".I wonder if anyone has had any success with them? Shouldn't they carry a warning,that they may seriously damaged ones appliances?.

They do.....in the instructions that come with it after you´ve installed it

The guy who installed mine has said that the one he installed for me, is the last he is doing, and is going to insist that his clients pay the extra and get the PSW invertor in future, because no one is ever happy with them.

[ENIGMA]

I have a 300w inverter,I brought 20 years ago.Its heavy,noisy and draws 5 amps with no load,attached.I assume it must be a PSW as I never had any problems but I haven't used it much due to it's inefficiency.I would guess modern PSW inverters are far more efficient.