Talk:Power inverter

Archives

Archive 1 contains the contents of the talk page of a stub article that has been merged into this article. Pogorrhœa (talk) 00:54, 6 January 2017 (UTC)

Diagrams

This page would really benefit from some diagrams. Alaric 14:55 May 8, 2003 (UTC)

I'd like to see a better diagram than the tube oscillator - which isn't even correct, since the plate voltage supply is backward! --Wtshymanski 18:43, 14 March 2006 (UTC)

The general case

I think this should say that a transformer is ran at a set frequency, but also, a 50 Hz transformer will operate on 60 Hz. Any transformer will operate on higher frequencies with losses no higher than the design frequency, but not vice-versa, until the frequency gets high enough that thinner laminations, or a different core material is required. You can reference the Wikibook article on transformer design here.

--Craxd (talk) 21:23, 7 May 2011 (UTC)

Good short article

I think this is one of the better articles explaining electronics on Wikipedia. --Grouse 12:14, 19 Jul 2004 (UTC)

I agree. Explains what was needed. However I think external links should point to sites that contain more info about the topic. Commercial sites should be tagged as such. Does anyone else think the same? I am new here, hence I'm hesitant to change the main page --Padme 21:44, 17 Aug 2005

From the first paragraph of the text, it would seem to me that the opposite would be true for computers. Most PSUs take in alternating current from the wall and convert it to direct.

You really need to understand switched mode power supplies to understand this. Perhaps the link should be more closely coupled to the psu references, rather than just mentioned at the end of the paragraph. StealthFox 18:48, 13 December 2005 (UTC)

I took out he following sentence: An inverter can have one or two switched-mode power supplies (SMPS).. Maybe it's the other way around? --Apoc2400 07:23, 3 March 2006 (UTC)

PDM/digital power inverters

Do digital power inverters exist? Do there exit any power inverters, analog or digital, that use pulse density modulation (PDM)?Myrtone (the strict Australian wikipedian)(talk)|contributions|Testpage

There are many manufacturers of Variable Frequency Drive inverters. They have generally adopted the latest electronic components and design techniques as soon as they have been able to do so. Today, most of these products use embedded microprocessors to control IGBT transistors. Most products use some form of PWM strategy to provide a simulated sine wave output with controlled voltage and frequency.

I am not familiar with PDM, but it appears to me that the zeros and ones all have the same fixed width and the modulation consists of controlling the number and position of ones vs. zeros. What happens if there are two ones in succession? Does that become a pulse that is twice as wide? I think that PWM power inverters operate like PDM with a lot of instances of two or more ones in succession joined to form wider pulses. Because of the switching losses in the power switching devices, the switching frequency is usually limited to 3 to 9 kHz but the widths and positions of the pulses are adjusted in very small increments. Manufacturers usually publish a product's switching frequency but don't often provide details about the specific scheme that they use for setting the widths and positions of the modulation pulses.

I hope that helps to answer your question. -- C J Cowie 15:36, 14 March 2006 (UTC)

Ambiguity

"Modified-sine inverters may cause some loads, such as motors, to operate less efficiently."

The above sentence is in the article. I can't understand if it means that modified-sine inverters are worse (cause some loads to be less efficient) than a no inverter or than a simple inverter. In other words, the waveform generated by a modified-sine inverter is being compared to what? To a true , perfect sinewave or to the waveform of a simple inverter (one with only two possible voltages)? Ambiguous.

Since I don't know the answer, I can't correct by myself.

Just saw your unsigned comment. (I have no idea when you wrote it.) Anyway, reading the above quote ("Modified-sine inverters may cause some loads, such as motors, to operate less efficiently."), I would answer your question thusly:

A modifed sine wave inverter may cause certain types of loads, such as motors, to operate less efficiently than when powered by [alternating current in the form of] a pure sine wave, whether that sine wave be from a "pure sine wave" inverter or regular AC power from the wall outlet. In other words, Pure Sine Wave = best; Modifed Sine Wave = less so. (Square Wave = worst of all.) How much of a difference it actually makes in ordinary practice, I don't know. I regularly use a Modifed Sine Wave inverter to power my microwave oven, and although it causes the oven to "buzz" a little, and seems to heat the food somewhat more slowly (than when powered from the regular wall outlet), it seems to work okay. Hope that helps. Captain Quirk (talk) 18:56, 15 February 2009 (UTC)

Modified Sine Wave here would refer to 3 level types, the ones most common available. The problem is that operating shaded pole and other "synchronous" motors on a Modified Sine Wave source can cause those motors to operate erratically or make a loud buzzing sound, due to the harmonics. For most motors it may be fine and just produce a bit of extra heating, but shaded poles are very frequency sensitive. Mostly clocks, record players, etc. — Preceding unsigned comment added by 72.8.4.74 (talk) 02:15, 3 April 2014 (UTC)

Disambiguation

I don't think this page should get primary-topic disambiguation. The word 'inverter' is used very often to refer to NOT gates. --Smack (talk) 02:03, 14 June 2006 (UTC)

What??

"An inverger is an inverter and a charger in a single unit." What is in inverGer? I assume that is a typo, but if it were corrected then the sentence read "An inverter is an inverter...". Anyone know what point was trying to be made here? — Zero10one 10:22, 8 November 2007 (UTC)

---

"Simple inverters generate harmonics which affect the quality of power obtained using them. But PWM inverters eliminate this by means of a sine wave cancellation using the properties of Fourier Series." — Omegatron 16:04, 28 October 2006 (UTC)

Hmmm this is indeed a strange explanation... What about something like "Simple inverters generate square waveforms which are not suited to some application (especially transformers and motors), because of their high harmonic content. In this case, PWM inverters can be preferable" ? CyrilB 16:40, 28 October 2006 (UTC)

Certainly better. I'm just trying to figure out what the original author was trying to say. PWM inverters generate a more smooth sinusoidal waveform (if built well), while simple switching ones generate a filtered square wave, but what does this have to do with sine wave cancellation or the Fourier series? — Omegatron 18:20, 28 October 2006 (UTC)

The only thing that the Fourier series has to do with this is that the concept of harmonic distortion, based of Fourier analysis, is used to quantify the quality of inverter output waveforms. "Harmonic cancellation" may be a useful way of describing the effect of PWM techniques in improving the waveform, but it doesn't make much sense as presented. -- C J Cowie 20:45, 28 October 2006 (UTC)

"What??" is a good title for this section. I can't figure out what the first part has to do with the rest, nor what these comments are referencing in the article. - KitchM (talk) 18:20, 12 November 2009 (UTC)

Some of the comments here are correct but, to clarify, both PWM and PDM (Pulse Decimation Modulation) rely on producing a pure 180V square wave (the same voltage used by simple square wave and modified square wave inverters) with harmonics at 60 Hz that can be filtered with a simple and low cost PI filter and the quality of that filter leaves a very low distortion sine wave at 60 Hz and 120 VAC. PDM, by the way, is what a "Digital Amp" uses like the ones from TI's Pure Path Digital Audio Amplifier line of ICs.Joseph Perkins (talk) 13:32, 5 February 2014 (UTC)

Quality of an inverter

The use of the term pulse may need some clarification in thie paragraph:

The quality of an inverter is described by its pulse-rating: a 3-pulse is a very simple arrangement, utilising only 3 transistors, whereas a more complex 12-pulse system will give an almost exact sine wave. In remote areas where a utility generated power is subject to significant external, distorting influences such as inductive loads or semiconductor-rectifier loads, a 12-pulse inverter may even offer a better, "cleaner" output than the utility-supplied power grid, and are thus often used in these areas. Inverters with greater pulse ratings do exist.

I believe that the term pulse here refers to the number of steps in the inverter waveform. The six-step waveform is described in the article. A square wave would be a two-step waveform. There are also multiples of the six-step waveform such as 12-step, 18-step and 24-step.

The term pulse is often used to describe AC to DC converters. I can't find any references that use the term pulse as it has been used here.

If no one objects, I think I will change this paragraph to describe 12-step, 18-step and 24-step inverters and eliminate 3-pulse etc.C J Cowie 21:31, 8 November 2006 (UTC)

The article Pacific Intertie describes 6-pulse converters. I've long intended to look up what that means and verify correct usage. Are you proposing to eliminate mention of 6 pulse? — EncMstr 00:09, 9 November 2006 (UTC)

The 6-pulse and 12-pulse converters described in the Pacific Intertie article are phase-controlled AC to DC converters and also the same circuits operated as line commutated AC to DC inverters. This article does not cover line commutated inverters. There are also load commutated inverters that are not covered here. These are all controlled rectifier circuits. I think that it might be best to cover the various types of controlled rectifier circuits all in another article and eliminate the terms 6-pulse and 12-pulse from this article.--C J Cowie 00:47, 9 November 2006 (UTC)

Three Phase Inverters

The three phase inverter section is dominated by line commutated inverter information. PWM three phase inverters need to be broken out into a separate section.

Also, voltage source and current source inverters need some coverage. —Preceding unsigned comment added by Wefoij (talk • contribs) 23:10, 2 September 2007 (UTC)

True sine

So how does a true sine or pure sine inverter work? --Pascal666 01:12, 1 November 2007 (UTC)

There is no such thing as a true or pure sine inverter, every inverter has some harmonic distortion. Inverters labeled as True or Pure sine are really making a relative comparison to other inverters on the market. The small consumer and domestic inverters generally are either modified sine which is the square wave with gaps waveform mentioned(THD = 30%), or variations on PWM output (which can usually get THD of about 2% - for comparison, an audio amplifier with 2% THD would be considered low-fi).

For common PWM inverter designs the power is boosted via a DC-DC converter then fed via an H-bridge to the output. The control of the H-bridge is the dominant factor in the final output, as power transistor tech improves the switching speed increases and the THD decreases. For comparison, coolamp produce a 90% efficient switched amplifier with THD < 0.01% (you can consider the DC-AC portion of an inverter as a specialised amplifier). --Jaded-view 00:34, 3 December 2007 (UTC)

All DC/AC inverters use a transformer based forward converter to convert some DC voltage to a much higher DC voltage (typically 12VDC to 140-180VDC). All a forward converter is doing is operating as an oscillator with a push/pull driver (can be any kind of switch, but symmetry of drive is crucial) feeding the transformer at some arbitrarily high frequency. The higher, the smaller the transformer for a given power rating. The output of the transformer is rectified to about 140 to 180 VDC and fed to the output stage. This is then one of many forms: A simple 60Hz H bridge where opposite transistors are off and on at the same time produces a 140V Peak to Peak square wave (RMS voltage 120VAC). A controlled 60Hz H bridge that makes one intermediate step of all drivers off produces a "Modified Square Wave" output. Adding a second voltage tap and expanding the H bridge into a double H bridge gives a better "Modified Sine" wave. Running the H bridge at some arbitrarily high frequency as in PWM or PDM modulation and adding a simple PI filter to remove those high frequencies leaves a fairly clean 60Hz sine wave. The more sections in the PI filter and the higher the modulation rate, the cleaner the sine wave.Joseph Perkins (talk) 13:49, 5 February 2014 (UTC)

modified sine

The term modified sine redirects here. Our WP:REDIRECT#PLA guideline suggests that we should have the words "modified sine" in bold in the first few paragraphs of this article. Currently, the word "modified" currently does not appear anywhere in this article (except in the External links section). That external link illustrates a "modified sine" with a picture that looks like a square wave to me. I thought "modified sine" was different from a square wave?

Previous discussion (talk:inverter (electrical)#Ambiguity) about that phrase apparently refers to an ancient version of this article before that word was removed[1].

Was important information accidentally lost in that ancient edit? Which one of the waveforms currently described in this article is the "modified sine"? --68.0.124.33 (talk) 00:21, 28 August 2009 (UTC)

My understanding was that a "modified sinewave" is a waveform that is on positive for a quarter cycle, then zero for a quarter cycle, then negative for a quarter cycle then zero for a quarter cycle. This waveform has the important characteristic that it's peak to RMS ratio is the same as a sinewave.

The peak to RMS ratio is important because resistive loads rely on the RMS voltage of their supply while rectifier based loads rely on the peak value. A square wave inverter that is set up to provide the correct voltage for rectifier based loads will provide an overvoltage to restive loads and a square wave inverter that is set up to provide the correct voltage for resisitive loads will provide an undervoltage to rectifier based loads.

The current article seems to completely ignore the peak to rms ratio and treats "total harmonic distortion" as if it is the only important parameter of an inverters output. Sadly I don't have enough experiance to fix this myself. Plugwash (talk) 02:46, 16 August 2011 (UTC)

You are correct. A better way of creating the modified square wave (frequently incorrectly called a 'modified sine wave' - there is nothing sinusoidal about it, probably the product of marketing folk), is to add two regular square waves together, one of which is phase shifted by 90 degres relative to the other. By the way: the illustration in the article does not correctly depict such a wave as the two square waves appear to be phase shifted by much less than 90 degrees (somewhere around 33ish degrees). 86.162.113.8 (talk) 14:28, 18 February 2014 (UTC)

Request for ENF Link

We have been researching solar inverter companies for over three years, and have built up a list of 170 solar inverter manufacturers here: ENF PV Inverter Industry Directory

It is not only a list of all the inverter manufacturers around the world - we have also researched the power range they are producing, and whether they are on-grid or off-grid inverters.

I notice a link on the page already to an information page on solar inverters, and I think that the page I am suggesting is just as relevant and I would highly appreciate an appropriate link being added.

Kit Temple (talk) 02:57, 3 March 2009 (UTC)

Looks like a well done and highly useful link. I think it makes a fine addition to the article. —EncMstr (talk) 05:46, 3 March 2009 (UTC)

re. Electric Vehicle Drives

There is a little confusion in this section where it states, "In vehicles with regenerative braking, the inverter also takes power from the motor (now acting as a generator) and stores it in the batteries.".

This should probably state two different possibilities. One is that the drive motors are DC and another where they are AC.

If they are AC, then they would need a rectifier when they became alternators and began generating AC current. If they are DC, then they would need neither an inverter or a rectifier (but perhaps a transformer) when they became generators and began generating DC current for the batteries. - KitchM (talk) 19:06, 12 November 2009 (UTC)

I do not believe that a AC motor generates AC at a free spin. I have set-up VFD's on boiler blower motors and have often ran into one certain problem. See a VFD "using rectifiers" monitors back voltage to determine or gage its speed, if you will, on a programmed scale. This back feed is called the DC bus voltage back feed of the AC motor at a free spin. As the control demands less from the motor and ramps down producing a decrease in frequency. A ramp down time must be programmed as a blackout period until the motor is delivering a DC bus back feed that correlates to the frequency output of the drive.70.144.11.71 (talk) 14:22, 7 May 2010 (UTC)

Electric motors in hybrids and in "all electric" vehicles are more related to stepper motors. This is evidenced by the three conductors fed to each motor. This makes the sense of AC or DC a rare duck as it is both and neither.Joseph Perkins (talk) 13:58, 5 February 2014 (UTC)

Waveshape marketing

It would be interesting to find a reference that compares the much-maligned sqaure-wave inverter with the so-called "pure sine wave" types for computer UPS purposes. Since the first thing that the AC power hits in the power supply is a rectifier, say good-by to the "sine" wave early on; it seems to me that a square wave might be a much better waveform to feed a rectifier than a sine, since the peak and RMS values are closer. There's nothing in a modern personal computer that cares about the wave shape. You could probably run a computer power supply on white noise if you could get enough of it...--Wtshymanski (talk) 16:53, 3 March 2012 (UTC)

recently had a pair of books out of the libary that covered invertors and they may be of use for references here . "Power electronics" Lander, Cyril W, ISBN: 0070841624, 9780070841628 . And "Principles of Electric Machines and Power Electronics", Sen, P. C. ISBN: 0471850845, 9780471850847 Contrary to this article both recon square wave invertors can be fine for powering devices which have significant inductance eg big motors, as the inductance smooths out the current waveform -The powered device needs slightly derated to account for the difference in I-V curves.Yes that can play havock with the power factor (Affects the supply, not the powered device, and can be mitigated with by power factor correction) Not sure how it would effect low inductance electronics but probably worth a read. 82.47.140.47 (talk) 14:37, 14 March 2012 (UTC)

The problem with feeding anything but a pure sine wave to a UPS is it can, and does, cause the UPS to see the incoming power as being "bad" and it will switch back and forth between battery and AC power and not survive this very long. That's why cheap inverters and generators with THD higher than 5% must NOT be used with a UPS.Joseph Perkins (talk) 13:53, 5 February 2014 (UTC)

Requested move

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: pages moved, this page to Power inverter, the dab page to Inverter (disambiguation), and the base name Inverter made into a redirect to the primary topic Power inverter -- JHunterJ (talk) 17:50, 15 April 2012 (UTC)

---

• Inverter (electrical) → Inverter
• Inverter → Inverter (disambiguation)

– This meaning is primary per WP:PRIMARYTOPIC: it is much more likely, and more likely than all others (inverter (logic gate)), to be the topic sought, and seems that it will continue to be so with respect to long-term significance. Page views in last 90 days: inverter (electrical) = 186k, inverter (logic gate) = 26k. Note also many articles in the subset of inverter (electrical), listed there under Types. ENeville (talk) 19:48, 2 April 2012 (UTC)

• Support. The electrical inverter is a common/general term; the logical one is a specialist's term. --Born2cycle (talk) 21:19, 2 April 2012 (UTC)
• Oppose – page view counts differing by not even one order of magnitude is not a strong enough case to hijack a perfectly good disambig page via a primarytopic claim. Dicklyon (talk) 22:23, 2 April 2012 (UTC)
  • I don't understand where the 10 times the page views comes in as a threshold. Guidelines don't say anything about that. They say "much more likely". Any support for the 10 times threshold? ENeville (talk) 16:38, 10 April 2012 (UTC)
• Oppose disambiguation page should remain primary. The logic gate is also prominent. 70.24.244.198 (talk) 02:31, 3 April 2012 (UTC)
  • "Disambiguation page should remain primary" is a nonsensical statement. Only topics can be primary topics. It's possible for there to be no primary topic, in which case the dab page is placed at the base name in question, if that's what you mean. --Born2cycle (talk) 02:54, 4 April 2012 (UTC)
    • There is a primary location so it is not a nonsensical statement. 70.24.244.198 (talk) 04:32, 4 April 2012 (UTC)
      • What do you mean by primary location? The base name, Inverter in this case? I suggest it's confusing to refer to a location as being "primary" when we already use the "primary" descriptor to apply to topics. --Born2cycle (talk) 16:19, 4 April 2012 (UTC)
        • Fwiw, I don't see anything confusing about describing a dab page as "primary". It simply means that it's the first page the reader will be directed to. Jafeluv (talk) 07:58, 10 April 2012 (UTC)
          • It's confusing because it conflates the meaning of "primary", which means the topic most likely to be sought for a given term, with what is at that term. For example, the topic of the article at Paris is primary not only for "Paris", but also for Paris, France and Parisien, which redirect to that article. But there is no primary topic for Parisian, which has other common uses and so is a dab page. To say that the dab page is primary for "Parisian" is confusing, because "Parisian" has no primary topic. --Born2cycle (talk) 22:07, 11 April 2012 (UTC)
            • Yeah, I understood what you meant. I just disagree with your opinion. Jafeluv (talk) 08:02, 12 April 2012 (UTC)
• Oppose pointless loss of utility in a title. Noetica^Tea? 21:50, 3 April 2012 (UTC)
• Oppose. The electrical inverter belongs to the field of electrical engineering; the Boolean logic type of inverter belongs to electronic engineering. The fields rarely overlap, so there is rarely any confusion in conversation. There's an apples-and-oranges thing going on with the page hit examples. Instead of comparing page hits of electrical inverters with page hits for logic gates, it would be more accurate to compare electrical inverters (there are many types listed in the article) with logic gates in general, and to compare this specific logic gate (the NOT gate) with a specific type of electrical inverter, say, solar inverters. It was probably more common to talk about electronic inverters, or NOT gates, back before they were incorporated into integrated circuits, and you could hold one in your hand in the form of an 8-pin chip, but inverter logic gates do still exist and are still significant. Neotarf (talk) 09:05, 5 April 2012 (UTC)
  • Rarely overlap? Everybody is using the same math and physics. These are specializations in the great field of electron pushing, at best - they aren't disjoint. And an inverter (electrical) almost certainly has a bunch of inverters (logic) in it, for that matter. --Wtshymanski (talk) 13:18, 5 April 2012 (UTC)
    • Indeed. In the power electronics article, we learn that "power conversion systems can be classified according to the type of the input and output power", e.g., "DC to AC ((electrical) inverter)". Rather than electrical vs. electronic, which term is "primary" may depend on whether you are a power engineer or a computer engineer. --Wbm1058 (talk) 20:46, 13 April 2012 (UTC)

• A lot more people seem to be looking for this article (68k views vs. 9k views for the logic gate), so making this the primary topic seems like a reasonable suggestion. If there's no consensus for that, I think electrical inverter would be a better form of disambiguation than the current title (per WP:NCDAB point #1). Jafeluv (talk) 07:58, 10 April 2012 (UTC)
  • Electrical inverter would also be natural disambiguation and preferred per WP:PRECISION. ENeville (talk) 16:38, 10 April 2012 (UTC)

• Support. The page counts are suspect as the digital logic term is so closely connected to internet technology. In my dialect, inverter certainly means 12V (or more rarely 24V) DC in, and AC out (of whatever voltage and frequency). Worth relisting maybe? Andrewa (talk) 16:54, 11 April 2012 (UTC)
  • As I think about names, maybe inverter (logic gate) should be moved to NOT gate?... ENeville (talk) 17:15, 12 April 2012 (UTC)
    • Have done so: Talk:Inverter_(logic_gate)#Requested_move. ENeville (talk) 17:58, 12 April 2012 (UTC)
      • This idea of moving one article to a less common name so that another can use a more ambiguous name seems wrong-headed. And these claims of what "inverter" "certainly means" are very colored by where one is coming from. To me, it means the logic gate, and using that term as shorthand for the electrical AC power maker always seemed like a very strained application of terminology. I understand these devices are more likely to be found in a store these days (with the possible exception of Radio Shack and Fry's), so more people are going to be familiar with that product, but with only 6X more references, I don't feel that the "much more" criterion is satisfied here. The disambiguation plays a very useful role, so let's not flush it. Dicklyon (talk) 18:41, 12 April 2012 (UTC)
        • I'm not trying to subjugate the article on the logic gate. I'm just proposing changes to improve the organization of WP. Obviously, opinions on what constitute that vary, and productive debate will hopefully pursue that end. I am concerned about the "not even one order of magnitude" threshold because it is both undescribed on WP:PRIMARY and seems like a disproportionate standard. Please note that I have raised the policy issue at Wikipedia_talk:Disambiguation#Primary_topic_threshold. ENeville (talk) 20:32, 12 April 2012 (UTC)

• Oppose this move, and support Inverter (electrical) → Electrical inverterPower inverter and Inverter (logic gate) → Logic inverter or NOT gate. Inverter is a plain English word and linking to Inverter could create WP:OVERLINK problems (Avoid linking plain English words). Wiktionary defines invert as "to turn (something) upside down or inside out" and inverter as "something that inverts, or causes inversion." What is being inverted should be clearly disambiguated in article titles, without using the awkward parens construction which should only be used for minor uses of a term when there is a primary use, which there is not in this case. -Wbm1058 (talk) 21:44, 13 April 2012 (UTC)
  • Seems reasonable to me. I guess the argument per guidelines would be that "inverter" itself is not precise enough per WP:PRECISION and should be disambiguated regardless, preferably naturally. ENeville (talk) 00:54, 14 April 2012 (UTC)
• Support. If this subject gets more than 50 percent of the relevant traffic, then it should be primary, per WP:PRIMARYTOPIC ("more likely than all the other topics combined"). The 7-1 page view numbers actually understate the dominance of this subject, since the logic gate is most often referred to a "NOT gate". I googled inverter -wikipedia and checked the first three pages of results. Almost all of these hits refer to this subject, with one partial title match. There is nothing at all about the logic gate. AC is not the opposite of DC, so the terminology is dissatisfying. But it is entrenched usage. "Electrical" is a disambiguator that doesn't disambiguate as the logic gate operates on electricity as well. Kauffner (talk) 02:08, 14 April 2012 (UTC)

Actually logic inverters can be electronic, fluidic, mechanical, abstract, or whatever. By I agree that "(electrical)" is a poor way to try to make this title more precise. I'd call it a Power inverter. It may not be the most common name, but it's not far behind, and is much more precise and recognizable. On the other hand, Electrical inverter is almost never used (at least according to Google shopping). Dicklyon (talk) 03:02, 14 April 2012 (UTC)

Duh. After making a point about power electronics above, I still went along with Electrical inverter. I believe you're correct on this. Power inverter is the obvious choice for the article title. That still leaves open the possibility of Inverter redirecting to Power inverter, with an about hatnote there to Inverter (disambiguation). I'm open to that as a compromise, since the number of articles on specific types of power inverters leans that in the direction of dominant usage here. —Wbm1058 (talk) 17:48, 14 April 2012 (UTC)

I like power inverter too. You can't literally invert power, as you can electricity. So it is more obvious that this is just a common name for a device. Thus it is less likely to lead to misconceptions as to how electricity works. Kauffner (talk) 10:30, 15 April 2012 (UTC)

Good point of clarification for the confused ;) – power has many meanings. There is an obvious need for disambiguation on Wikipedia—there are even separate articles for the field of physics and electric power. So, yes, it is not a rate that is transformed. I suppose when used in the term power inverter the meaning is closer to that of electric power industry as in "Electric power is transmitted..."—again, it's not a rate that is transmitted. Googling "power inverter" the only link to electrical inverter I see on the first page is to this Wikipedia article! On the other hand, googling "electrical inverter", most of the links are to power inverters! But transformer may offer better guidance on what to do about inverter. That goes directly to the electrical device, with a hatnote to Transformer (disambiguation). It is similar in that both are plain English words: transformer: "Something that transforms, changing its own or another thing's shape." However a key difference is that I don't see any alternate meaning that even remotely challenges for primary meaning—just albums, flying cars, book titles, etc. I think the key question to decide on the disambiguation issue is how high to set the bar to determine "unchallenged primacy". –Wbm1058 (talk) 15:43, 15 April 2012 (UTC)

• Comment/Questions - I noticed that Inverter (air conditioner) was recently moved to Air conditioner inverter. I'm unfamiliar with this concept, but the impression I have from the current air conditioner inverter article is that the article discusses a particular type of power inverter used in a certain type or types of air conditioners. But when I Google Inverter air conditioner I get a lot of hits, that give the impression there is a particular kind of air conditioner known as an Inverter air conditioner, which could possibly be shortened to simply "inverter" when discussed among air conditioning specialists. And it is not clear to me that with Inverter air conditioners whether it is power, or something else (motor speed?) that is being inverted. [2] –Wbm1058 (talk) 21:51, 14 April 2012 (UTC) And here [3] is a discussion of Digital VRF vs. Inverter VRF. What is VRF, is it variable refrigerant flow? Is this page talking about Digital scroll compressor technology? Why isn't the word inverter even used in the scroll compressor article? –Wbm1058 (talk) 22:06, 14 April 2012 (UTC)

Proposal on how to close this request

This request has been up for over a week and is now on backlog. Based on the above discussions, I believe we can form a consensus to:

• Move Inverter (electrical) → Power inverter
• Postpone decision on Inverter (disambiguation) until after the move request at talk:Inverter (logic gate) is closed, opening a new move request for Inverter if still desired

—Wbm1058 (talk) 16:02, 15 April 2012 (UTC)

"Power inverter" is a relatively rarely used term. I think a hatnote is enough to distinguish this article from a "NOT" gate - there's not a lot of uses for the term "inverter". --Wtshymanski (talk) 16:23, 15 April 2012 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

littleboxchallenge.com

https://www.littleboxchallenge.com from Google

Is it must be included into a page? --Nashev (talk) 12:25, 28 July 2014 (UTC)

No. BTW. the winner is at [ http://littleboxchallengecetpower.com/ ] --Guy Macon (talk) 04:35, 3 January 2019 (UTC)

Battery section

It seems like the battery section should be removed. The storage of the output energy is not relevant to inverters themselves. At the very least, it should be listed under applications. — Preceding unsigned comment added by 129.170.131.235 (talk) 05:36, 7 March 2015 (UTC)

RMS/peak ratio of modified sine wave

The respective section currently states: "The peak voltage to RMS voltage ratio does not maintain the same relationship as for a sine wave."

This should be clarified to state that is is true only in general, for arbitrary choices of the duty cycle. It is possible specifically to choose each "on" period to be equal to each "off" period to achieve the desired RMS/peak ratio, as stated in Root mean square#RMS of common waveforms.

I have not been bold because I don't have a good reference at hand. --SoledadKabocha (talk) 20:57, 4 February 2017 (UTC)

Years later - if you think about the definition of RMS (the square root of the average of the squared value), you can soon persuade yourself that if the pules is "on" hlaf the time and "off " the other half, its RMS value is 0.707 of the peak value (square root of its average (squared)value of 0.5). In that sense, the thre-step waveform can be made to have the same ratio between "peak" and "RMS" value as a sine wave. Hence the marketing expression "modified sine wave", I expect. --Wtshymanski (talk) 19:05, 19 April 2019 (UTC)

Marketing term vs power electronics textbook terms

What Figure 5-21, page 203 of Cyril W. Lander Power Electronics Third Edition calls that 3-step waveform is "quasi square wave". It's as close to a square wave as it is to a sine wave. "Modified sine wave" is a marketing term, not a power electronics textbook definition, so just like "all natural" or "pH Balanced", we are at the mercy of marketroids for definitions. In any case, that 3-step wave form is what you find coming out of the cheaper 12 volt to AC adapters. "Pure sine wave" would have to be a product of PWM and filtering, because no-one would want to try to sell essentially a linear AC amplifier that would dissipate about as much power as it delivered. --Wtshymanski (talk) 19:05, 19 April 2019 (UTC)

Re: "no-one would want to try to sell essentially a linear AC amplifier that would dissipate about as much power as it delivered",

• Datasheet for linear and switching AC power sources:[4]

I'm just saying. --Guy Macon (talk) 20:16, 19 April 2019 (UTC)

Care to speculate how many of those get sold each year, compared to, oh, say, how many UPSes are pushed out the door by your favorite local office supply store chain? (And on further reading, some of these products are PWM, too.) --Wtshymanski (talk) 21:01, 19 April 2019 (UTC)

Modified sine wave?

A three step waveform produced by many inverters

This illustration was recently added to the article as an illustration of the modified sine wave generated by some inverters. It is, however, not a modified sine wave and owes absolutely nothing to sine waves and doesn't even remotely resemble a sine wave. Such inverters are often described by their manufacturers as modified sine wave purely as a marketing ploy to make the inverter sound better than it actually is. This probably explains why the wave is generally much incorrectly described.

A true modified sine wave has an output that looks like the waveform shown here (first picture down). This has some resemblance to a true sine wave. Some not so quite expensive inverters modify the wave by having the shoulders at half the amplitude of the peak.

The wave illustrated right is more correctly described a modified square wave (for inverter use) though an even better description would be a pulse wave. Switch mode power supply circuits operate reasonably happily from such a wave form though to obtain an R.M.S. voltage of 230 volts requires a peak voltage of around 380 volts which is still significantly higher than the 326 volts of a sine wave. (The illustration shows a peak of 176 volts for a 114 volt R.M.S. which fits the maths for a 50% cycle) This is one of the characteristics of pulse waves.

The real problem with modified square wave inverters is that they should never be used to power transformer input equipment (or equipment featuring any form of wound component such as a motor). This is because the R.M.S. of any current pulse wave is very much larger than the mean (and for the wave shown, 1.66+ times that of the mean - or 1.5+ times the equivalent sine wave R.M.S.). Although the power supplied through the transformer is dependant on the mean current flow (true for this wave but not for a sine wave), the copper losses in the transformer windings are determined by the R.M.S. current squared. This means that the heat dissipated in the transformer windings is over three times that for a sine wave.[1] The reference above lists some equipment which will not operate satisfactorily from a modified square wave.

A true modified sine wave has an R.M.S. current much closer to the sine wave value and although transformer windings will see an increase in I²R losses, they can usually cope with the more modest increase. Even the not quite so expensive versions of the modified sine wave are a little worse and any overheating depends on how marginally rated the transformer is.

[1] The same problem exists in capacitor input filter linear power supplies where the current rating of the transformer secondary winding has to be at least double that of the DC output current (and primary to match) precisely because the R.M.S. of the pulse current that flows is much larger than the mean current. It is only double because the pulse width is larger than 50% at full load. Transformers built for capacitor input filter use are usually rated for the DC current to allow for this. 81.129.194.138 (talk) 17:31, 20 April 2019 (UTC)

And I have just noticed that the user who uploaded the illustration and has edit warred over it being a modified sine wave has argued the opposite in the thread above. 81.129.194.138 (talk) 17:34, 20 April 2019 (UTC)

• Implementation Of A Microcontroller Based Pure Sine Wave Inverter
• DC/AC Pure Sine Wave Inverter
• Analysis of Single-Phase SPWM Inverter
• Modified Sine Wave Inverter Circuit
• Pure Sine Wave vs. Modified Sine Wave
• A week ago Friday our Cobra modified sine wave inverter died...
• Difference Between Pure & Modified Sine Wave Inverters
• Understanding Pure Sine Wave, Modified Sine Wave and Off-Grid Inverters
• Pure Sine Wave Power Inverters
• When to purchase a modified sine wave inverter?
• Should I Purchase a Pure or Modified Sine Wave Inverter?
• The Best Pure Sine Wave Inverters To Buy
• Modified Sine Wave Inverters
• A Guide to Power Inverters
• Why will 26 1.2W 220V LED lights not work with an 800W inverter?
• Modified Sine Wave vs. Pure Sine Wave Inverters
• Pure Sine Wave VS Modified Sine Wave Inverters

Any questions? --Guy Macon (talk) 19:23, 20 April 2019 (UTC)

These are all the marketing department's use of modified sine wave to describe a modified square wave. I have pointed out above what a modified sine wave is and is not. You cannot have two obviously different wave shapes with the same description. It would be the same as someone describing what we all recognise as a square wave as a sine wave. 81.129.194.138 (talk) 11:44, 21 April 2019 (UTC)

Bullshit. My first four references have nothing to do with any marketing department. Meanwhile, your only citation is a blog and fails to claim that the pictured waveform is the only waveform that is considered a modified sine wave. Please provide a citation to a reliable source that explicitly supports your claims. --Guy Macon (talk) 15:58, 21 April 2019 (UTC)

Bollocks! The illustration above is of a modified square wave and not a modified sine wave. Any reference claiming differently is just plain wrong (like the majority of Wikipedia articles). The modified square wave does not even begin to fit the profile of a true sine wave. Although usually illustrated as though it fits inside, it is only because the two waves are drawn to different scales. If both waves are 100 volts R.M.S., the sine wave has a peak voltage of 141.4 volts but the modified square wave has a peak voltage of 165.2 volts (for 50% pulse width), which does not even begin to fit inside. On the other hand a true modified sine wave drawn to the same scale fits reasonably well around a true sine wave with more or less half of it inside and half of it outside with a peak voltage roughly the same. That is why the latter is a modified sine wave and the former is not. 81.129.194.138 (talk) 12:44, 22 April 2019 (UTC)

Nobody cares what you think. You are free to believe that "Any reference claiming differently is just plain wrong (like the majority of Wikipedia articles)" but if you edit any articles to insert your unsourced opinions, you will be blocked from editing Wikipedia. See WP:V and WP:RS. --Guy Macon (talk) 13:00, 22 April 2019 (UTC)

And in spite of your claims, your references actually support my stance:

Your first reference illustrates and describes it as a 'modified square wave'.

Your second reference is an academic paper with no clue as to the source of the information.

Your third reference illustrates and describes it as a 'modified square wave'.

The forth reference is an enthusiast site unsupported by a recogniseable authority so is unreliable.

The fifth reference is a product page and therefore likely tainted by marketing bullshit and therefore unreliable.

The sixth is a blog and therefore unreliable.

The seventh and eighth are product sites so unreliable.

The ninth illustrates and describes the wave as a 'modified square wave'.

The tenth is a blog.

The eleventh is a product page so unreliable.

The twelfth is pushing pure sine wave invereters and even claims that the 'modified sine [sic] wave' has a lower peak voltage than a true sine wave which the maths just does not support because it is significantly larger as the illustration above clearly shows and so it is obviously unreliable.

The thirteenth and fourteenth are product pages so unreliable.

The fifteenth illustrates and describes the wave as a 'modified square wave'.

The sixteenth is a blog.

The seventeenth illustrates and describes the wave as a 'modified square wave'.

Funny how the only reliable references that you give above describe it as a modified square wave (five of them).

So we can therefore conclude that it is correctly described as a 'modified square wave' and not a 'modified sine wave'. You therefore appear to have no reliable references supporting your incorrect claims so the person editing in violation of WP:V and WP:RS is yourself so you are the one who should be blocked.

Any questions? 81.129.194.138 (talk) 12:44, 22 April 2019 (UTC)

Please provide a citation to a reliable source that explicitly supports your claims. --Guy Macon (talk) 14:02, 22 April 2019 (UTC)

For the benefit of the hard of thinking: FIVE (5) of them are highlighted in green above and were provided by yourself in support of your own incorrect argument. I therefore have no need to provide anything further at this stage as you have not provided any reliable reference supporting your position. Please provide at least SIX (6) valid citations that explicitly support your claim. 86.164.61.64 (talk) 12:37, 24 April 2019 (UTC)

That five-step waveform isn't a sine wave any more than the three-step waveform is a sine wave. "Modified sine wave" is a marketing term, like "aircraft grade aluminum". If you buy a product that says it produces a "modified sine wave", the only thing you can be sure of is that it isn't making a sine wave. It would be nice to have some referenced text that talks about the practical limitations and effects on load of 3-step, 5-step, and PWM-type inverter waveforms. Peeling the lid off marketin jargon is a good role for an encyclopedia, I think. --Wtshymanski (talk) 23:20, 27 April 2019 (UTC)

As an off-grid homeowner and technologist with (now ancient) experience on a sine-modulated UPS design project, I have long since accepted "modified square wave" and "modified sine wave" as synonymous. I judge the former to be more descriptive of the time-domain wave shape and the latter to be more of a marketing term. IMO arguments as to the legitimacy of the latter are pointless since both terms are established and the latter dominates "in the wild."

You said "It is, however, not a modified sine wave and owes absolutely nothing to sine waves and doesn't even remotely resemble a sine wave."

I would argue that these waveforms owe everything to sine waves. Every periodic waveform can be described as the sum of some number of sinusoids of different amplitudes, frequencies and relative phases. Both square and modified sine waveforms have their main sinusoidal component at the fundamental frequency, and a bunch of harmonics that we classify as distortion since in the ideal they would not exist. While still requiring only a single pulse per half-cycle, the modified sine waveform has less of this harmonic garbage than the square wave -- the sole reason for its adoption.

The behavior of loads is dependent on the waveforms' frequency-domain makeup, rather than their subjective appearance in the time domain. The "modified sine wave" term may be annoying, but the fundamental sine wave is very definitely present in the waveform. WillingScott (talk) 02:50, 29 December 2023 (UTC)

Non-diode/analog based inverters.

An inverter is a machine the takes a DC input and generates an AC output. This article however focuses almost entirely on solid state inverters that use various diode types and arrangements to generate their AC signal. The article does mention in passing Motor-Generator sets and Thyratrons, however we should do more to showcase other historical, or mechanical/analog inverters as they are both interesting in their ingenuity, and useful for historical perspective. We should also give more explanation to each of these analog inverters as some of the linked articles only give a cursory overview and lack deal depth. 31173x (talk) 02:24, 9 April 2020 (UTC)

That's generalizing "inverter" beyond what is commonly accepted as its definition. At best we could link to articles on electromechanical methods of developing alternating current, but no-one called a motor-generator set an "inverter", (as an example). --Wtshymanski (talk) 17:12, 12 April 2020 (UTC)

Contradiction in 'Input and Output's section

These statements under "Output Waveform" -> "Sine Wave" there are the following two statements which seem to contradict each other:

1) ".. just a less choppy output than the square wave (two step) and modified sine wave (three step) inverters." 2) "Sine wave inverters with more than three steps in the wave output are more complex and have significantly higher cost than a modified sine wave, with only three steps, or square wave (one step) types of the same power handling."

So is a square wave one or two step? JackW2 (talk) 04:03, 26 September 2021 (UTC)

Stand-alone inverter article?

Should there be an article on stand-alone inverters? After all, we have one on grid-tie inverters. It's also used as a link target, even from See also lists, yet we don't have an article on it or any content in this article.

There used to be an article but it was deleted as "pollution", which is crap. Slava Ukraini fellas (talk) 10:57, 8 October 2022 (UTC)

"CCFL inverter" listed at Redirects for discussion

The redirect CCFL inverter has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2024 February 9 § CCFL inverter until a consensus is reached. Utopes _{(talk / cont)} 08:07, 9 February 2024 (UTC)