240VDC TO 240VAC

You might want to look up VFD (Variable Frequency Drives) on the net. Most are AC to AC, but nothing prevents it from being DC to AC.

Start with a DC to AC converting oscilator (designed to desired frequency) large enough to deal with 240V. Then, on the output side, use a additive transformer. The additive transformer is an ordanry transformer with one leg of the primary connected directly to the secondary. The number of turns difference in each side determine how much current boost you will get. With the primary and secondary connected this way, the voltage will stay the same on both sides. Other than one side of the primary and secondary connected together (in phase with each other), the transformer is connected in the normal fassion, and the schematic looks the same except for the extra line conncecting the two sides. Hope I was helpful.

Electrically Speaking--you need to restate your problem thus:

" I want to use 30Amps sinusoidal(or Square wave) from 240V RMS Sinusoidal A.C-50( or any) Hz.

I have only a 240Volt D.C.Source.

Can somebody suggest Commercially available eqipment to achieve that?"

<Is there a circuit?>---- A number of Inverter Makers have.

<Like using a oscillator transistors> Well , there isn't anything of that name-but circuits can be built using Transistors like IGBT to create a self oscillation from the 240VDC source.

<And a 1:1 transformer ??> a Transformer and other complicated circuitry will be a must to :

1. Convert the switched Square wave into a Sine Wave(if you must) and
2. To get the Sinusoidal output voltage to 240Volt RMS.

240 VDC source may have to be drained substantially more than 30 Amps.

There is also an old fashion way of using an MG set.

Your post does not give desired frequency or number of phases.

Personally I would use a commercially available inverter.

Be aware you indicate an impossible 100% efficiency, so in reality you will need to draw more amps from the DC side.

THOSE WERE MY FIRST THOUGHTS EXACTLY!

I agree w/ GW

Old MG converters had little more than 60% efficiency. Electronics have made great strides in improving efficiency, but 100% reaches for the goals of those searching for perpetual motion technology.

No matter your solution to converting DC to AC at equal voltages, or amperages, I'm about certain that you will need to increase your inputs of amperage or voltage, or accept lower outputs due to losses in the process.

Many devices such as the switched mode PSU's in computers etc are quite happy to be fed from a DC supply as the first thing that happens in these devices is that the AC input is rectified to DC but the supply voltage should be about 330v.

Try to get Swithed-mode Supply or Circuit from a Vendor like RS Components

RS Components Ltd

Distributor

RS Components Ltd PO Box 99 Corby Northamptonshire NN17 9RS

United Kingdom

www.rswww.com

It's power comes to:

230x30= 6900W

It is not a project of home design.

If a conventioal supply is seeked it will be bulk just over

Just see Transformer @50/80 Hz over 7KW >40Kg cost = in your country & provision of manufacture ??

FRONIUS HAS THE PRODUCT !

SEE HERE :

http://www.solarelectricsupply.com/Inverters/Fronius/index.html

But it too expensive....

I need 50 herts ! Can i oscilate with a 555 oscilator and a mosfet transistor, working in a 1:1 transformer ( 240v 240v ) ?

Im Paulo Lobo, in Portugal again...

What about this circuits ??

Any will work ??

Please go to http://imagenerd.com/show.php?_img=loboTmoL.jpg

to take a look !!!

Reply infos and coments here and to ct2gnh@hotmail.com

Theoretically you get out a squarewave output of uncontrolled frequency and uncontrolled on/off timing ratio.

Your output transformer is fixed--so you get a highly distorted-uncontrollable 230( nearly)VAC of highly non-sinusoidal waveform out.

If you want something better ---and have bigger problems to worry about---buy one DC>AC Sinewave Inverter correctly rated+ a Variac+a voltmeter at the output to trim a little.

Do you really need AC many devices will work just as well on DC?

But the Problem is "I have D.C --want A.C."

Yes, but sometimes looking at the big picture from another angle provides other solutions that are easy to do.

Do we have a solar power system with DC and have lots of power to figure out what to do with it, or is it a charged battery that needs to run a specific load etc.

I was under the impression this forum is not a narrow exam question but should allow for some creative solutions.

Why dont anyone come up with a good circuit....

DC to AC 50hertz...

Output 220v Ac 50hertz

Input from 120v dc to 240v dc....

Do that .

All hints at Post# 10.

You do not seem to appreciate the complexity of these devices, if you do not have the skill to design one and either do not have the funds to purchase a commercial unit or believe you could build one more cheaply than the proffesionals I can only suggest you rent a commercial unit, reverse engineer it and build a clone

why NOT!

That surely is a way out.

Hi, im a space engineering, and what your looking for its easy to make !

Using a oil motor, with two connectings side, the motor is speed controled pulsing 50hertz this two connectings.You must only control the oil moto speed.

Please reply to help you !

No doubt that this is a fine way out. Solves all problems. Only non-electrical intervention is an oil control circuit in between. Want it?