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6 or 7KW Inverter Needed


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Inverters are about 85% efficient. Therefore to make an output of 7kW the battery power must be 8.24kW. Somehow, you must get rid of 1240W of heat.
If you could find an extremely high-power 12V battery then it must produce a whopping 687A continuously. Most batteries and alternators would explode. Maybe the entire truck full of paralleled batteries.
Wires the size of your arm!
Hundreds of transistors.
Impractical.

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Hi renaldo,

A 4kW inverter will draw something like 400A from your 12V battery. A big starter battery for a diesel pickup can supply 400A for a few seconds but the voltage at this current will drop to about 10.5V this will raise the current to 460A. I recommend using a higher voltage like 24 or 48 Volts, this way the current will be half or one fourth compared to 12Volts input. Even at these higher voltages you need big powerful truck batterys. The commercial inverters for 12 V input are seldom above 1000 W continuous power, and for a good reason!

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hello can pic be posted on this forum because i have a acdc power suply and i would like someone to look at it and see if i could use some parts out of it to build an inverter and it has a small inveter built in because the fan on it runs off 115vac but i dont know how much watts it is but if i could put pics up on this forum then someone could see what im talkin about

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Renaldo,
It is as ante has mentioned: An inverter such as your request is not normally built from a 12VDC supply. Batteries are connected in series and parallel groups to convert from a much higher voltage. Some actually convert 120 VDC to 120 or 240 VAC.
It is easier to keep them charged and you do not lose as much energy in the conversion.

MP

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Hello!
I do not know why you need such a big inverter. It is uneconomical to build a large inverter (I have seen in eBay.de for sale modified square wave inverter 8kW continues and 16kW surge for about 300EUR). Do you have one big load or many smaller? I have different small loads and I bought instead of one big inverter few smaller ones which was more economical way to go.   

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Where did you see a sine-wave inverter article in the link? I only see square wave. Did I miss it or are you having fun with Renaldo?

MP


The underlined link is a 2kW PWM inverter that uses many high power Mosfets driving two huge paralleled ferroresonant transformers with a sinewave output.
Link: http://www.technology.niagarac.on.ca/people/mcsele/i2k.htm

Quote: "a software bug led to both sets of FET drivers being switched-on simultaneously. During such a fault condition the system can easily consume over 1000A from the battery!! (enough to cause a fire) as it did on one prototype inverter tested."

That project was 6 or 7 years ago. They might have it improved today.
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Hello!
I do not know why you need such a big inverter. It is uneconomical to build a large inverter (I have seen in eBay.de for sale modified square wave inverter 8kW continues and 16kW surge for about 300EUR). Do you have one big load or many smaller? I have different small loads and I bought instead of one big inverter few smaller ones which was more economical way to go.
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ok well can a power supply be build inside the inverter that would give you 12 or 48 volts and a nice high am which would keep the load off the batteries. with this the life time of the batteries would be much longer. the inverter would pull from the power supply instead of the batteries and i have this software that calculate the specs for you i put in what i want and it told me how much volts and size capacitors i needed well if you want it let me know and check it out and see whats use it could be

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I am sorry but after reading your last post ” ok well can a power supply be build inside the inverter that would give you 12 or 48 volts and a nice high am which would keep the load off the batteries………..”  I very much doubt that your skills will cover a project like this!

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