Pure sin wave inverter

[Tahmid]

As long as flux density is within limits, you can transfer maximum power with 2 turns in primary and also with 4 turns in primary. The resistance of 2 turns or 4 turns is not enough to sufficiently restrict the current, so both can transfer maximum power.

But if you use 4 turns in primary, you're under-utilizing the core. So, you're winding more turns but not utilizing the core sufficiently. Even with 2 turns, the core is under-utilized. But with that, you're staying at safe levels. You might even be okay with 1 turn.

Hope this helps.
Tahmid.

 

[kabeer02]

check this...**broken link removed**

 

[--BawA--]

Many many thanx tahmid
If I wound only one turn on primary then all the remaining portion of the bobbin will be empty...then where should I wind a single turn (middle or at the edges of tge bobbin)?? How many thin wire strands should I use to make a resultant of 16 gauge wire so as to minimise the skin effect .I will use at 80khz frequency?? Is 16 gauge wire is sufficient to drive the 50 amp current ???

 

[BradtheRad]

How many thin wire strands should I use to make a resultant of 16 gauge wire so as to minimise the skin effect .I will use at 80khz frequency?? Is 16 gauge wire is sufficient to drive the 50 amp current ???

A table of wire gauge-versus-ampacity (see post #31) lists 6 AWG as suitable to carry 50A.

If the duty cycle permits then you might get by with a thinner gauge.

An internet search will turn up tables listing skin effect for various frequencies.

(Thought I'd give Tahmid a break.)
:^)

 

[--BawA--]

how can i wind the transformer centre taped using only 2 primary turn?? rest of the area in core will be vacant??

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anyone please attach the photo of 2 primary turns on primary side ,,,i m confused ,,,

 

[--BawA--]

Tahmid ,,please tell me the difference between half bridge and full bridge topology,,?? i have designed a transformer which is giving 316 volts output if my input is
10.5 0 10.5 (centre taped),,,i want to know which topology should i use ,,ie half bridge or full bridge??

 

[kabeer02]

Tahmid ,,please tell me the difference between half bridge and full bridge topology,,?? i have designed a transformer which is giving 316 volts output if my input is
10.5 0 10.5 (centre taped),,,i want to know which topology should i use ,,ie half bridge or full bridge??

you can use both depending on your desinge,in pure sine wave inverter for 12v we use 7v in the primary and 230 at secondary but it all depend on your switching frequency.

 

[Tahmid]

Tahmid ,,please tell me the difference between half bridge and full bridge topology,,?? i have designed a transformer which is giving 316 volts output if my input is
10.5 0 10.5 (centre taped),,,i want to know which topology should i use ,,ie half bridge or full bridge??

Since you've wound the transformer with center tap, you might just use push-pull.

For low voltage to high voltage conversion (step up), you shouldn't use half-bridge, at least not capacitor-based. You can use full-bridge, but drive becomes more complex. And since you've already wound a center-tapped transformer, you might just as well use push-pull.

Hope this helps.
Tahmid.

 

[--BawA--]

Tahmid .
..for winding the input side of transformer one should use thin wire strands simply in parallel or to twist all the wire stands into one and then wind?
Nd plz plzz give me the schematics of inverter...I hve wound the transformer myself .but I dont hve schematic of driver n power stage..so plzz give me schematics of inverter using sg3525 or nyother ic...as I dont hve knowledge of pic....I m searching since two month but didn't get any schematic .so plzz tahmid help me out.i will be very thankful to u..

 

[Tahmid]

You can find a few circuits here: https://www.edaboard.com/threads/228090/

 

[--BawA--]

can i use arduino board in place of pic microcontroller,,to generate spwm??

 

[--BawA--]

Hi tahmid
Plzz tell me the working of feedback in ic sg3525?
And I m very much confused about spwm technique to get sine wave..so plzz tell me the basics of spwm ., how t works .in detail.??

 

[karthick1987]

Hi Mate,

With the SG3525 the feedback would have to be through a voltage divider. Look at the datasheet and look at it again. Also the SPWM is is an averaging of a square waveform to replicate a digitised sine wave. Thats all it is. IT can be generated by comparing a sawtooth waveform of a particular frequency with an actual sine wave. that gives you the resultant SPWM

Hope this helps
K

 

[Tahmid]

can i use arduino board in place of pic microcontroller,,to generate spwm??

It doesn't matter what you use to generate the SPWM as long as you generate it, be it with a PIC, AVR, ARDUINO, ARM or some other controller.

 

[--BawA--]

hi tahmid
1) I want to learn about PIC microcontrollers . I haven't used it earlier.so please give me the tutorial link , from where i can start from basics as i dont know anything about PIC.?2) also give the component list to buy ?
3) i want to make a programmer by myself so please give me its schematics...?

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hi tahmid
Is atmega328 is capable of generating SPWM ??

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please see these attachments and reply..

 

[kabeer02]

mr bawa , i think you need to understand how SPWM work first , pure sine singnal is an analog signal not digital ,so dont feed in analog signal to your mosfet because their will be alot of losses and you will end up wasting your money and time , simply visit tahmid blogs you will understand everything.

 

[Tahmid]

hi tahmid
1) I want to learn about PIC microcontrollers . I haven't used it earlier.so please give me the tutorial link , from where i can start from basics as i dont know anything about PIC.?2) also give the component list to buy ?
3) i want to make a programmer by myself so please give me its schematics...?

1) Here is a good free book: https://www.mikroe.com/products/view/285/book-pic-microcontrollers-programming-in-c/
2) To start off with, get the PICs, crystal oscillators, capacitors and other basic electronics components. Make sure you have a good lab power supply you can use. Get some 7805s if necessary. Get some LEDs to experiment with.
3) You can easily make a PICKit2 clone. You can find loads by searching on the forum. You'll need to get a PIC18F2550 programmed from somewhere else though.

hi tahmid
Is atmega328 is capable of generating SPWM ??

Of course, but you need to be able to make it generate the SPWM. Bear in mind it doesn't have something like the ECCP module of the PIC. So, you need to use the PWM module. Shouldn't be too difficult after you understand how SPWM works.

You should first understand how SPWM works. SPWM works by using square wave outputs that you use to drive the MOSFETs. The square wave signals vary in duty cycle to "emulate" a sine wave and after filtering, the output signal is a sine wave.

I will see if I can make a tutorial on SPWM or give you some links.

Hope this helps.
Tahmid.

 

[--BawA--]

hi
i have completed my 1st stage of the inverter i.e 12vdc to 311vdc ,,but i am facing a problem . when i connect a 15watt bulb to the 311 vdc output ,it glows fine ,but when i connect a 100watt bulb , it does not glow,.i rewound the transformer but the same thing is happening agian ,so please tell me where is the problem? i have used ETD44 core with 3 primary turns and 102 secondary turns. operating frequency is 50khz. In primary turns ,12 number of wires in parallel are used.each wire has AWG23 and in secondary AWG22 is used.

 

[Tahmid]

Upload your circuit diagram. Then it'll be easier to find out where the fault lies.

What do you use as your power source? When you use 100W bulb and it doesn't light, measure the voltage on the 12V DC rail. Also, when the 15W bulb lights, measure the voltage on the 12V DC rail.

 

[--BawA--]

thanx tahmid
that fault is resolved now,,there was a problem in my wire that connects the battery to the circuit.wire was too thin to drive the 10 amp current ,, as i replaced the wire with a thick one ,,100 watt bulb glowed ,,,
but there is still a small problem- At the transformer output i have used a bridge rectifier using ultrafast HER503 diodes and 400V 47uFD capacitor, when i measure the output voltage with NO LOAD the voltage is around 560volts, but when I connect 100watt bulb ,the output dc voltage goes to 227volts. and when i connect 2 bulbs of 100watt each then output voltage goes to 130volts. till now i havn't used any feedback ,so i want to know where is the problem? is there a problem in my transformer ? my turn ratio is around 35,, and ETD44 core can handle around 450 watts but in my case it cannot handle 200watts,, so please tell me where is the problem??