12v to 220v 800w inverter

Thread Starter

Jahangir Alom Sumon

Joined Jun 13, 2019
4
Hi. I am a student. I am pursuing BSc in mechanical. I need a durable and liable 220v 800w pure sine wave inverter for my project (DC to AC). I have 12v 100Ah solar battery which is charged by solar panel. I want to use this inverter at home. Total power demand of the home is 500w. I need help. May I get a pure sine wave inverter circuit?
Thank you.
 

dendad

Joined Feb 20, 2016
4,426
Indeed! As AlbertHall says.
You cannot make one anywhere as cheap, compact or efficient as you can buy one.
This is proved by you needing to ask for a circuit. If you need to ask for a circuit, you plainly cannot make one. They are not as straight forward and simple as you may expect.
 

rsjsouza

Joined Apr 21, 2014
383
As others have said, even if you had an Electrical/Electronics degree, the amount of experience to build such inverter goes well beyond a schematics diagram, especially if you need a pure Sinewave output. Aspects such as physical clearances between components, thermal management of the high power semiconductors, provision for fail-safe and protection devices and methods are only a few of the additional considerations.

Even still, only with more experience you will be able to optimize your system to reach compactness and efficiency.

That is why folks are reluctant to provide such information and endorse what could become a dangerous experiment. 800W @ 220V can end up quite badly for both the circuit and the operator.
 

MisterBill2

Joined Jan 23, 2018
17,763
As an interesting and inexpensive experiment, you can seek out a used UPS power unit that has batteries that need to be replaced. At least here in the USA they are usually discarded because the replacement battery pack costs almost as much as a new UPS system. Then you can try connecting the UPS to your solar-charged battery pack. But do not purchase a used UPS device, they are usually available free. Your expense would be for the wires to use to connect it to the solar battery pack.
Now for a capacity calculation: I will presume 100% efficiency to make the math easier. 500 watts @12 volts is 500w / 12v = 41.66 amps, and 100 Amp Hours / 41.66 amps = 2.40 hours. so a 100% efficient inverter will give you almost 2 1/2 hours of 500 Watt power.
At this point it is clear that you need a smarter inverter that only draws enough current to power whatever load is connected. That would be a load sensing regulated inverter, That is a bit more complex than just a simple inverter. Such inverters are available, and you may even find a design for such someplace on this site. But it is an area where I have not done any design work.Good luck!
 

Joël Huser

Joined Jun 30, 2019
42
1/ you did never mention the AC frequency of your home made inverter, is it 50 or 60 [Hz] or with tunable frequency ?

2/ Are you sure you need a 220 [VAC] and not 230 [VAC] AC output RMS voltage ?

3/ I wish that you have all the ressources to build a home made inverter, because it is a huge challenge ! The ressources ?
  1. An electronics laboratory with adapted tools
  2. Something like 5 electronic engineers during 2 [years]
But go one, build one, it is through such challenges that you will deeply learn elctronics.....
 

MisterBill2

Joined Jan 23, 2018
17,763
1/ you did never mention the AC frequency of your home made inverter, is it 50 or 60 [Hz] or with tunable frequency ?

2/ Are you sure you need a 220 [VAC] and not 230 [VAC] AC output RMS voltage ?

3/ I wish that you have all the ressources to build a home made inverter, because it is a huge challenge ! The ressources ?
  1. An electronics laboratory with adapted tools
  2. Something like 5 electronic engineers during 2 [years]
But go one, build one, it is through such challenges that you will deeply learn elctronics.....
An inverter is not that terribly hard to create, really. Optimizing for the very best efficiency and very lowest cost is a different thing, but a basic inverter is fairly simple. Just research them at the "schematicsforfree" website. Lots of designs, some better and some not, but quite a few could be quite simple.
 

debe

Joined Sep 21, 2010
1,389
If you want to build a Pure Sinewave inverter this is the way to go. The EG8010 board is quite cheap to buy on E bay.INVERTER.7.jpg SINEWAVE INVERTER PCB.2.jpg SINEWAVE INVERTER PCB.jpg
 

dendad

Joined Feb 20, 2016
4,426
I purchased on of them quite a while ago, but have not got around to trying it out.
A number of old UPS units sit waiting in my shed, ready yo be sacrificed for the project.
But one of the main things the TS stated, is he wants smaller size that the commercial ones, at least that is my take on it.
I doubt that is easily attainable, starting form a zero knowledge base.
 

MisterBill2

Joined Jan 23, 2018
17,763
There are two things that are quite difficult to shrink, one is adequately sized transformers that don't saturate and cause distortion, and the other is adequate heat sinks that remove enough heat to avoid excessive temperature rise. But since the circuit will not need to also charge a battery or provide change-over and line filtering, some of the circuits could be smaller. But a low-distortion 800 watt transformer will not be small. Of course the one other factor is the TS definition of "small".
 

MisterBill2

Joined Jan 23, 2018
17,763
The simple way is to get a copy of the service manual for the Honda sine wave generators, which have all of that circuitry in a small package. and have a reputation for being reliable.
There is no need for random experimenting and damaging components, that is the method used by those who really do not have adequate understanding of circuits and specifications. Since you are not trying to create anything new, it makes sense to copy a design that does what you want and is already known to work well.
 

debe

Joined Sep 21, 2010
1,389
Service manuals for digital sine wave generators like Honda dont give circuit diagrams for the actual inverter board. They only give a general wiring diagram. The circuit is set in resin & pretty mutch not removable, as ive tryd to on a faulty inverter.
 

MisterBill2

Joined Jan 23, 2018
17,763
Service manuals for digital sine wave generators like Honda dont give circuit diagrams for the actual inverter board. They only give a general wiring diagram. The circuit is set in resin & pretty mutch not removable, as ive tryd to on a faulty inverter.
Thanks for the information. I had based my suggestion on the performance, not any actual experience. But if you still have the resin encased section it may be possible to remove that material and reverse engineer the system. That could be useful for a lot of folks.
 

SamR

Joined Mar 19, 2019
5,019
Years ago an electronics Engineer friend was working on his fish finder and couldn't find a schematic of the circuit so he called Humminbird and asked about it. They gladly mailed him one and explained that they didn't publish them because the Chinese would copy them exactly except for the logo printed on the board.
 

Joël Huser

Joined Jun 30, 2019
42
Years ago an electronics Engineer friend was working on his fish finder and couldn't find a schematic of the circuit so he called Humminbird and asked about it. They gladly mailed him one and explained that they didn't publish them because the Chinese would copy them exactly except for the logo printed on the board.
That's why I give a part of the cake to a differents chinese male or female who represent his or her company. So all my knowhow is not in only 1 company. Because they are the best with reverse engineering.....
 
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