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ElectroEgg
Apprentece
Trinidad and Tobago
7 Posts |
 Posted - May 22 2008 : 9:25:23 PM
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Hi audioguru, as you can see I am new here. But not particularly new to electronics. I am a EEET level 1 student who likes to do practicals whenever I have free time. I am currently working on an inverter project. I've tried Aaron's schematic twice and ended up with 4 fried transistors and 3 fried capacitors. After that I decided to read the forums from pages 1-45  . Since you are the expert hear can you help me design an inverter circuit? All I have to start is a 10A Transformer with 12v-0-12v IN and 110/220v 60/50Hz OUT. This would be able to deliver 120W right? Please feel free to correct me if I am wrong, I am eager to learn. Oh! I would like to run a 110W Television or a 100W radio on it. Would these be able to work on a square wave? |
Edited by - ElectroEgg on May 23 2008 01:28:43 AM |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - May 23 2008 : 10:50:08 AM
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Hi ElecroEgg,
I have already helped enough people make a very simple inverter on this website.
A radio and TV might not work from a square-wave inverter because their power supply usually runs on the peak voltage of a sine-wave which is 1.414 times higher than a square-wave. In The Philippines they have TVs that run from any voltage from 80V to 150V and they work fine from a simple square-wave inverter.
Your little transformer is designed to have an output of 12V-0V-12V when it has a load of 10A and the primary has 110V or 220V. Its output is probably 13.5V-0V-13.5V without a load. So when you turn it around and put a 12V square-wave into it, its output voltage will be 12V/13.5V= 0.89 times what you expect and lower when loaded.
A transformer with a higher power rating will not have such a high loss.
The circuit will not give a 12V square-wave because the transistors or Mosfets have a voltage loss (that heats them). So the output of an inverter using your transformer will be about 100W at 90V or 180V. |
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ElectroEgg
Apprentece
Trinidad and Tobago
7 Posts |
Posted - May 23 2008 : 9:53:02 PM
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| Hmmm...That's bad news Audioguru. Because that was the largest Transformer I got after checking various electronic shops. I payed a wopping $160TT ($20ca) for it and at that same store I saw a 400w inverter for $400. I will be at a great loss if I will have to buy another larger one (which obviously will cost more than the first). Oh well I got to forget my losses and see if I get a 15 or 20A Transformer. It's just that I get such a great feeling when I build something myself. Thanks a lot for your help. |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - May 23 2008 : 11:01:42 PM
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Hi ElectroEgg,
$20ca is nothing in Canada. I can buy a pretty good 100W inverter for $20ca. I think it has a modified sine-wave output but it mighr have a true sine-wave output so it can power anything up to 100W. It doesn't use a huge heavy transformer. It uses a voltage stepup circuit that operates at a high frequency so a small transformer is used and it uses high voltage Moafets instead of transistors. |
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ElectroEgg
Apprentece
Trinidad and Tobago
7 Posts |
Posted - May 24 2008 : 07:26:27 AM
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| Ok. Well I'm off for components searching. I hope I get the required ones for your 100w inverter. Since it's a square wave I will basically be able to operate only the lights at my home then. Hmmm....I'm just wondering. Do you know how to make a sine wave inveter also? |
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kivdenn
Nobel Prize Winner
Uganda
535 Posts |
Posted - May 24 2008 : 09:54:51 AM
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Hey am working on 48V DC-AC inverter circuit bellow.Please look at it and tell me if it can work.
Download Attachment:  48v inverter.jpg
70.37 KB
I have also tried to make a 48V low battery disconnect circuit for it. please also have a look at it and tell me if it can work. Thanks
Dennis
Download Attachment: 48v sensor.jpg
58.2 KB
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - May 24 2008 : 6:59:18 PM
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| I am tired of checking your millions of circuits. Maybe somebody else can. |
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ElectroEgg
Apprentece
Trinidad and Tobago
7 Posts |
Posted - May 24 2008 : 9:43:48 PM
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Hi Audioguru,
If you don't mind can you tell me what formulas you used and what calculations you did to determine that a 47k resistor will give 50Hz output and a 39K will give 60Hz output. |
Edited by - ElectroEgg on May 24 2008 9:58:20 PM |
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kivdenn
Nobel Prize Winner
Uganda
535 Posts |
Posted - May 25 2008 : 02:56:06 AM
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quote:
Originally posted by audioguru
I am tired of checking your millions of circuits. Maybe somebody else can.
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - May 25 2008 : 12:48:26 PM
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quote:
Originally posted by ElectroEgg
Hi Audioguru,
If you don't mind can you tell me what formulas you used and what calculations you did to determine that a 47k resistor will give 50Hz output and a 39K will give 60Hz output.
The formula is for The Classic Cmos Oscillator and is also shown on the datasheet for the CD4047 IC.
Download Attachment: Cmos oscillator.PNG
24.34 KB
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ElectroEgg
Apprentece
Trinidad and Tobago
7 Posts |
Posted - May 25 2008 : 6:10:21 PM
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| Oh I see. Thanks Audioguru |
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kivdenn
Nobel Prize Winner
Uganda
535 Posts |
Posted - May 26 2008 : 02:40:37 AM
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quote:
Originally posted by audioguru
I am tired of checking your millions of circuits. Maybe somebody else can.
Why, am I being so demanding or so bothering ? If so please tell me so that I un subscribe. Mr. Moderator I need your word on this because this is a very uncivilised way of talking to a person like me. If you cant reply me and fed of my millions of circuits as you say just keep it to your self, no body needs to know your ill feelings.And that question was not specificaly directed at you Mr.Audioguru so I dont see why you atack me with such rague. Am so disapointed at MR. Villageguru.  |
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JUAN DELA CRUZ
Mad Scientist
Philippines
476 Posts |
Posted - May 26 2008 : 04:09:51 AM
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quote:
Originally posted by kivdenn
quote:
Originally posted by audioguru
I am tired of checking your millions of circuits. Maybe somebody else can.
Why, am I being so demanding or so bothering ? If so please tell me so that I un subscribe. Mr. Moderator I need your word on this because this is a very uncivilised way of talking to a person like me. If you cant reply me and fed of my millions of circuits as you say just keep it to your self, no body needs to know your ill feelings.And that question was not specificaly directed at you Mr.Audioguru so I dont see why you atack me with such rague. Am so disapointed at MR. Villageguru.
Hi kivdenn....
Calm down my friend
Being a hobbyist like you in this forum, I know for a fact that Mr. Audioguru was a nice & cooperative person like Mr. Pebe.. They assist me in my modified sine inverter even though there is an obstacle between our language (not fluent in ENGLISH). In spite of everything they help me .........like you DENNIS!!!!
So I think you should be nice also instead of being rude.
MR. AUDIOGURU ANSWERED OUR QUESTIONS AT NO COST....FOR FREE!!!
"ANSWERING NUMEROUS QUESTION POSTED IN THIS FORUM
..............IS NOT AN EASY TASK"
ESPECIALLY WHEN THERE IS A HINDRANCE BETWEEN LANGUAGES
DENNIS DON'T BE MAD. MR. AUDIOGURU IS TIRED NOT BY HELPING YOU OR ME.
HE IS A PERSON LIKE YOU. EVERYONE CAN FEEL WEARINESS.
NOBODY IS PERFECT. |
juan dela cruz
Penniless INVENTOR |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - May 26 2008 : 09:26:12 AM
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If you need an inverter (I don't need one) then buy an inexpensive Chinese one that is modified sine-wave and has modern parts inside using a small high frequency transformer. It even has a digital display showing how much power is being used and the remaining battery life.
Maybe somebody can take apart a modern Chinese inverter and post its schematic and parts list here. |
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wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - May 27 2008 : 07:59:18 AM
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A PWM sine wave inverter can't be too expensive to make. I really think that. When I can, I'll make a parts list for a simple & straight forward PWM sine wave inverter. No more than 300W.
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When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
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12/120V inverter again
