I want to make a inverter transformer of 400w. in my local store i found many kind cores, all from old transformer mainly from ship breakings. some are heavy others not so heavy. some have black paints on it, some are gray, silver golden etc. I want to know which type is better for inverter transformer.
and the transformers primary 12-0-12v should have bifilar winding. should i wind the secondary 220v loop over the primary? or should i wind them side by side.
thanks
only cores are available.
Assuming you can separate the laminations from the coils, I think you should be looking for a 500VA transformer with a 220 volt primary, and remove the secondary (usually on top) and replace it with your 12-0-12 primary. You might even find a 220 to 24 volts center tapped to use as is.
I'm guessing he is in India from the "ship breaking" reference.
What frequency of inverter?
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** Oh dear - this Groper is really beyond all help.
...... Phil
he is a real time stupid.
I ask the things i don't know. If u don't know the answer just stay out. u don't have to be a sucker.
** But you did NOT ask them.
FUCKWIT !
message reported
** One cruise missile now on way to your location in Bangladesh .....
LOL !!!
....... Phil
sure. not a thief like u or ur ancestors!!
Play nice children. How is your Hindi - or other S. Asian language?
-- _____ _ _ |_ _| | | | | | | __ _ _ __ ___ | |__| | ___ _ __ ___ ___ _ __ | | / _` | '_ ` _ \\ | __ |/ _ \\| '_ ` _ \\ / _ \\ '__| _| |_ | (_| | | | | | | | | | | (_) | | | | | | __/ | |_____| \\__,_|_| |_| |_| |_| |_|\\___/|_| |_| |_|\\___|_| __ ____ / _| | _ \\ ___ | |_ | |_) | ___ _ __ __ _ / _ \\| _| | _ < / _ \\| '__/ _` | | (_) | | | |_) | (_) | | | (_| |_ \\___/|_| |____/ \\___/|_| \\__, (_) __/ | |___/
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There are several ways to design and build an inverter like the one you need. I assume you will have a battery input of 12 VDC nominal and want an output of 220 VAC at 50 or 60 Hz. If you will be using a "modified sine wave", which is actually a rectangular waveform roughly approximating a sine wave, you will have a primary waveform that is 12 volts peak, or about
8 volts RMS, so you will need a primary of 16 VCT. You can use a pair of high current MOSFETs or bipolar transistors driven by a logic circuit with the proper on and off times for the frequency you desire. The MOSFETs will need to handle pulses up to 100 amperes and voltage peaks of 30 Volts or more. It will probably require snubbers and other components to keep the inductance under control under all conditions, especially if the load will be inductive or regenerative (motor).A standard EI lamination power transformer core will work OK, but I don't know if the cores you have available from freight salvage are suitable. The color of the paint is irrelevant. If they were soaked in salt water and have had the windings cut off, chances are the cores will be rusty and possibly damaged. You need to do core loss and saturation tests on them to verify that they do not have excessive circulating currents when they are energized. To do this, you must wrap a number of turns as a primary and a secondary, and apply voltages while you monitor the input current, actual power, and output voltage. From this you can determine the number of turns per volt at which the core just begins to saturate, and use this to determine the number of windings you need. The true power with no load determines the core loss, which should be no more than about 5% of the VA rating of the transformer.
If the core is already assembled, it will be very difficult to wind it. If it is a C-core, you might be able to pull the halves apart and put new windings on a tubular form and put it back together, but usually the laminations are overlapped to reduce the magnetic gap. You could try sawing the cores apart, but that will cause shorts between the laminations, resulting in a very inefficient, noisy, and unreliable transformer. If you can find a toroidal core, as has been suggested elsewhere, you will need to wind it using a shuttle, but it will be more efficient.
If you don't understand what I have been saying, then it is doubtful that you will be able to design and build an inverter successfully. You will need to do some research, learn the technology, do some simple experiments, and be prepared to spend many hours and lots of money for multiple prototypes until you finally have something that works.
Or, you can spend about $30 for an automotive inverter and just plug it in. Your choice. Good luck,
Paul
Hello ruleworld - how are you? We all have to be beginners sometime. Ignore Phil, he does know what he's talking about and is very knowledgable with electronics, but his people skills need honing. In short, he's a bit of a rude prick a lot of the time. (You might have done better to post in sci.electronics.basics rather than ....design)
Among other things, the size and type of the core will depend largely on the frequency that you intend to run the inverter at, (as mentioned by Graham). (The higher the frequency, the smaller the core) If you're planning to use typical inverter frequencies ranging to 100kHz, an iron core intended for 50 or 60 Hz is not the best choice. What frequency did you intend?
... Johnny
Thanks Paul
i will use a 12v battery and the output will be 220 VAC at 50Hz.
i have done some homework and infact i made a inverter using only 555 ic and some 2n3055 transistors. its output is square wave and not able to run inductive load. and the transformer i used is only 55VA. now i have decided to build a circuit using a pwm controller ic SG3524. which should run inductive load. and yes the circuit uses IRFZ44 MOSFETs.
the cores are El type and i found some in very good condition. there are some cores which i will not need to saw bcoz they are tied by 4 screws in the corner.
the reason i asked for colour of the core bcoz i think they are not made of same iron. and i asked for weight bcoz for the same size their weight varies much. the heavier ones will cost me more bcoz they sell it per kilogram.
could u plz answer the following questions.
** You will need a laminated iron core that weighs about 6 to 7 kilograms to handle 50 Hz at 400 watts.
....... Phil
comment from a thief cannot be taken seriously.
Phil isn't known to be a thief, and he is known for being well-informed about transformers. He's not my favourite person either, but you'd do well to follow his advice.
-- Bill Sloman, Nijmegen
theft is their national occupation. every person from that country are son/daughter of thieves.
well-informed
What's your problem? Please explain what you just said, you little shit.
"Johnny Boy"
** He is just pissed off, cos his dad could be any one of hundreds........ Phil
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