sine wave inverters

cruisaderhilton · Senior Member

sine wave inverters

dragonfly1 · Senior Member

we have a 2500 watt 5000 watt surge inverter $278 from Bit deals on ebay works great Mishto brand runs washing machine coffee machine vacuum cleaner microwave in short bursts they are good to deal with and fast delivery

Dragonfly1

PeterD · Guru

The link does not open for me (Win 10 with Firefox.)

aussie_paul · Guru

PeterD wrote:
The link does not open for me (Win 10 with Firefox.)

Me either with W10 and Chrome.

Aussie Paul. smile

Cupie · Guru

aussie_paul wrote:
PeterD wrote:
The link does not open for me (Win 10 with Firefox.)
Me either with W10 and Chrome.
Aussie Paul.

Works for me ... Win10 & Chrome.

Can't help with inverter .. Sorry.

macka17 · Guru

Don't know about the inverters.
but I have a 40a Charger from Mishto in back of ute tray for general use.
Works fine..
Reasonable quality Chinese equipment. There's worse, and better on the market.

I've never bothered with the pure sine wave units.
and in 20 odd yrs. running everything.
never had a problem.

Big con from sales department I reckon.

Phil C · Guru

Hi all

One thing we all need to very aware of is the way these machines are marketed. Just because the label says 2500 watts doesnt necessarily mean it will deliver 2500W.

Some manufacturers like to use a peak to peak wattage measurement, in laymans terms if that is the case you can halve the actual label wattage by half, the problem with any AC measurements is there are many variables that can be used by unscrupulous manufacturers to try and fool us.

IMHO the very best thing you should do is look at the spec sheets before you unload your cash, if the total output wattage is measured in RMS then you will be pretty much on the money. RMS in AC terms is the heating effect or similar DC wattage for an AC wattage. P-P, PMOP, voltamps, are really not indicative of the true wattage delivered by the unit.

Also, and despite some of the above conversation, a pure sine wave inverter is the only one that will ensure any sensitive electronics will not be damaged as a result of modified AC. The danger with modified sine wave systems is that some deliver a square wave. If there is no transformer in the circuit then your equipment will be powered by a square wave, probably not the best thing for modern electronics.

Just to add to the muddle of numbers, is the losses that inverters are guilty of. Some inverters will have 10% of the output used just to produce the AC, others are more efficient. Just thought I would like to confuse you more.

Cheers and happy camping

oldtrack123 · Guru

Hi
As Phil has said ,be vary wary of inverter power ratings, unless stated as "continuous rating", it is pretty useless, as it could be only available for a few seconds & has no direct relationship to "continuous rating"

PURE sine wave inverter supply is very similar to mains supply &will run any 240V equipment within it's rating without any problems

MODIFIED SQUARE Wave inverters can be pretty crude in wave form & not good for & in fact can damage some equipment

The shape of the modified SQUARE wave will depend on both the number of steps used in an attempt to get a sine wave form & quality of smoothing circuit

-- Edited by oldtrack123 on Saturday 9th of July 2016 08:49:14 PM

-- Edited by oldtrack123 on Sunday 10th of July 2016 06:22:34 PM

Phil C · Guru

oldtrack123 wrote:

Hi
As Phil has said ,be vary wary of inverter power ratings, unless stated as "continuous rating", it is pretty useless, as it could be only available for a few seconds & has no direct relationship to "continuous rating"

PURE sine wave inverter supply is very similar to mains supply &will run any 240V equipment within it's rating without any problems

MODIFIED SQUARE Wave inverters can be pretty crude in wave form & not good for & in fact can damage some equipment
The shape of the modified SQUARE wave will depend on both the number of stepsÂ used in an attempt to get a sine wave form

-- Edited by oldtrack123 on Saturday 9th of July 2016 08:49:14 PM

Thanks Oldtrack., I have taken it upon myself to learn a bit about these machines. I think I now know enough to be dangerous, it lines up with the AC theory I have up in the old grey matter. Hope all is well in your corner of the planet.

Cheers

Cupie · Guru

Oh come on ... How come you guys are being so nice to each other on the Tech forum ... Isn't this where egos clash.

Before long you'll be waxing lyrical about Root Mean Square & Lisageous figures. Go on now correct my spelling.

aussie_paul · Guru

Cupie wrote:
Oh come on ... How come you guys are being so nice to each other on the Tech forum ... Isn't this where egos clash.
Before long you'll be waxing lyrical about Root Mean Square & Lisageous figures. Go on now correct my spelling.

lol Cupie. My "our latest van excursion" thread I expected to get hauled over the coals re my using auto gas from an out of date bottle. biggrin

Aussie Paul. smile

oldtrack123 · Guru

Cupie wrote:
Oh come on ... How come you guys are being so nice to each other on the Tech forum ... Isn't this where egos clash.
Before long you'll be waxing lyrical about Root Mean Square & Lisageous figures. Go on now correct my spelling.

We generally are all nice on this forum smile It is that other forum where things get a bit heated furious confuse

Phil C · Guru

oldtrack123 wrote:
Cupie wrote:
Oh come on ... How come you guys are being so nice to each other on the Tech forum ... Isn't this where egos clash.
Before long you'll be waxing lyrical about Root Mean Square & Lisageous figures. Go on now correct my spelling.
We generally are all nice on this forum It is that other forum where things get a bit heated

Oldtrack and I have found a new respect for each other. We have settled our previous differences and we both now obey the rules of this forum. Im afraid many folks have lost their places in this forum for bad behavior. I wont be part of that any more. BTW I dont own a CRO anymore so I cant view Lissajous figures anymore.

Cheers

-- Edited by Phil C on Monday 11th of July 2016 10:51:35 AM

Jaahn · Guru

macka17 wrote:
Don't know about the inverters.
but I have a 40a Charger from Mishto in back of ute tray for general use.
Works fine..
Reasonable quality Chinese equipment. There's worse, and better on the market.

I've never bothered with the pure sine wave units.
and in 20 odd yrs. running everything.
never had a problem.

Big con from sales department I reckon.

Hi smile

Sorry to drag the topic back from the mutual admiration society biggrin however this is my comment on what Macka says.

I too have used the cheap ' modified' square wave units for years. Perhaps 20 years, and still do carry a small one,150W and have a 900W, for charging phones, computers if we forget the 12V ones. Also use it for a fan sometimes and a few other odd things as necessary. It is usefull and never blew up anything electronic.

However the only thing I "blew up" was an inverter that I tried to use with a flourescent light. The output transistors failed as it did not like the PF capacitors in it. Lesson learnt.

I do have three pure sine wave inverters also. Older stvle and all bought secondhand. They can be good, heavy and efficient too. Two are auto start which helps to save power. The better ones will start motors, fridges etc with out problem. However they are the old heavy style with a transformer and Australian made. BUT they do the specs below! Try that with the new cheap ones !

I have seen problems with other peoples fancy electronic gear run with modified sine wave inverters. EG washing machines, even electric blankets, if they have silly displays and push button menu selections. However never seen a computer not work OK despite the salesmen BS ! I have run my laptop on the modified sine wave on and off for years.

Jaahn

Also included is the input current specs for those who may wish to know for cable sizes etc.

Selectronics Inverter 1200Watt

Demand Start Sensitivity
Response Time

3-20W
1 Second Max

User Adjustable

Input Current

75mA DC
90mA DC
0.65A DC
120A DC
150A DC
360A DC

60mA DC
70mA DC
0.75A DC
60A DC
75A DC
180A DC

Stand By
Stand By w/ Optional Key Pad
Inverter ON - No Load
Max Continuous
1/2 Hour Rating
Max Surge

12V Input

24V Input

CONDITION

1200W
1500W
3600W

Max Continuous
1/2 Hour Rating
Max Surge

-- Edited by Jaahn on Monday 11th of July 2016 03:57:38 PM

Phil C · Guru

Gday Jaahn, good to see you.

In answering your "mutual admiration society" comment. Personally, I feel thats a bit confronting, although I trust and suggest it was said in jest. However the fact remains that we all need to pay respect to others opinions no matter if we feel they are 100% wrong. There are comfortable (NOT politically correct) ways to correct a wrong comment.

The inverters have allway been a thorn in my side and needed me to do a wee bit of study to satisfy my curiosity. Anyway, it is good to see you and I trust all is well in your corner of earth.

Cheers

rockylizard · Guru

Jaahn wrote:
Hi
Sorry to drag the topic back from the mutual admiration society however this is my comment on what Macka says.
Jaahn

Gday...

I reckon the "smiley face" was a dead give-away Phil ... I read it as a friendly smiley comment.

cheers - John

Phil C · Guru

Yeah, Rocky... I missed that. Sorry mate. Time for another coffee..

Hope you are well mate.

DeBe · Guru

Thaught id just show you this little compact LCD CRO Phil c. They are available from Banggood on E Bay for $36.76 freight free, I have built 2 of them & use them quite a lot they are only 200Khz band width but are quite usefull for vehicle electronics. http://www.banggood.com/DSO138-DIY-Digital-Oscilloscope-Kit-SMD-Soldered-13803K-Version-With-Transparent-Acrylic-Housing-p-1051616.html The pictures are 240V ac through a small transformer fed to the CRO, showing the wave form, of Mains then a Jaycar 12Vdc to 240V ac 150W Square wave inverter. I have not had any trouble using this unit to run plug packs for phones or running a small 240V AC fan of it. I do have a larger CRO but I find this fits in the tool box & you can freeze frame it. There is a small amount of noise on the wave form which is in the internal pre amp, which I just ignore. DSO138 LCD CRO.1.JPG 50Hz SINE.JPG 50Hz SQUARE.JPG

-- Edited by DeBe on Tuesday 12th of July 2016 04:16:15 PM

Phil C · Guru

Hi DeBe, love the idea of the CRO. There will allways be discussion on mod square wave, square wave and pure sine wave inverters. For me I went the pure sine wave, way too many high $ gizmos to risk damage.

I looked on fee bay and may get a kit, although my hi rel soldering skills may be a bit low rel. May resort to load the board and get a mate to wave solder it.

Cheers

DeBe · Guru

On that particular kit all the surface mount components are already fitted, the rest are through hole components & not too difficult.