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# faizanbrohi

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1. ## Convert 0-30V 3A PSU to 5A or more

You Said this earlier for the 3A PSU and by the way how is the heatsink for the 3A PSU.
2. ## Stereo Audio power amplifier 2 x 40W - 80W

As the Site says '' A good starting point is using 4 turns for each primary (that is, 4 turns, centre tap and another 4 turns IN THE SAME DIRECTION). To calculate the number of turns of the secondary winding, multiply by the turns ratio. For example, if you want to build a +/-30V supply, the turns ratio is 30/13.8=2.2 approx, so wind 2.2 x 4 = 8.8 turns (better 9 turns, to overcome the diode losses) for each secondary (that is, again, 9 turns, centre tap and another 9 turns IN THE SAME DIRECTION). '' And ''Another possibility is using a toroid. You can extract it from a BIG power inductor. As a guide, a 4cm diameter toroid with a section of about 1cm2 can be used for a > 250W SMPS. Winding is a little bit more complicated than with ETD cores but with a little practice is not too difficult either.'' Now THe Idea is we can use it to make a >250W power supply using 4cm toriod and some wires. For my Output i would require 55/13.8 = 3.98 which is 4 turns and 4 x 4 = 16 turns . the problem is do i require a biggger toriod than the 4cm one ? If yes how big.
3. ## Stereo Audio power amplifier 2 x 40W - 80W

Actually it seems like i have to make a toriodal transformer which it says about 4cm Dia , Isn't there any simpler schematic please for god sake..
4. ## Stereo Audio power amplifier 2 x 40W - 80W

I think you are mistaken , i am talking about the Inverter That you send .. ;D
5. ## Convert 0-30V 3A PSU to 5A or more

THe TIP 31A is a change , the Two Paralleled 2N3055 is a change and the UA741 right.. I am making the 3A one , which value of capacitor do i use. The Picture of my another heatsink is as follows.with and without fan
6. ## Stereo Audio power amplifier 2 x 40W - 80W

I can use MJ15024 in this configration , they are 250W power transistors , to increase power , beacuse MTP75N06 is not manufactured as well as MTP60N06 THis only Leave BUZ11 and IRF540 , which can be found . but if i use MJ15024 in parallel combination with a good heatsink will it work Can You tell be a more simpler method , how i can order a transformer with input ratings and output ratings . so it is easy. (ie input voltage , centre tapped , output input current)
7. ## Stereo Audio power amplifier 2 x 40W - 80W

There is one problem , the output is only 35 and -35V , i neeed 55 and -55V
8. ## Stereo Audio power amplifier 2 x 40W - 80W

But the amplfiers that are in the market , especially Car Audio Amplfiers , are rated 1000W maximum value and 500W x 2 channel RMS IF i use one 250W for the Deck and the other one for the Car . i Will have to use a square wave inverter to produce 300W from a 12V car battery. and a square wave is easily converted to DC .
9. ## Inverter Circuit 12V DC to 230VAC Sine Wave

I think just using a simple LC Circuit at the output will be goood . but the problem will come as the RC circuit produces a sawtooth if a square wave is input . i don't know what happens to a LC Circuit , it would produce a sine wave , but will not be linear
10. ## Convert 0-30V 3A PSU to 5A or more

BY the way i will try to buy another bigger heatsink , which has four TO-3 Transistors output it is about half the size of the M250 audio Amplfier (250W). It cost's around Rs 100 to 110 . i will take that. But You were saying , that we can use two Output Transistors paralleled ,( i am talking about one Unit) . can you show me how ???
11. ## Stereo Audio power amplifier 2 x 40W - 80W

IT is to make Power Amplifier System with a CD Player and temprature display , 10 band VU meter and things like that.ok
12. ## Inverter Circuit 12V DC to 230VAC Sine Wave

Will a Ferrroresonant Transformer Produce a Sinewave from the Square wave input and one more thing , as shown in figure is it possible to use a simple transformer and then add a capictor at one end with some rating
13. ## Stereo Audio power amplifier 2 x 40W - 80W

No i am actually making two complete units with common input right , amd i am using 4 ohms speakers .
14. ## Convert 0-30V 3A PSU to 5A or more

But if i use the 2.2W x 12V fan , the Cooling will increase very well and will increase the thermal resistance
15. ## Convert 0-30V 3A PSU to 5A or more

Audio Guru , i also have the pic for the heatsink i am planning to use with this powersupply , and i was able to find the power transisitor TIP31A . THis heatsink is as closest i can find on farnell . which has thermal resisitance of 3.3 degrees C/W is this suitable. There is also a picture of the transformer
16. ## Stereo Audio power amplifier 2 x 40W - 80W

Well Here is another Amplfier i found of 1.5 KW how is this Baby . this can drive upto 1.5KW , this is insanity , but wait just calculate how many batteries :o Godd Help me . No way , i neeed something like a ferroresonant transformer and a square wave inverter that's allll ;D Further More this is the fans Pic , i am just asking do i include two fans on one heatsink or not ???. I am Eager to use one fan per heatsink . THe Fans are rated 12V @2.2W and 200mA approx . and no i am not using these heatsinks for the inverter , i am using them first for the M250 Amplfier , Stereo 500W x 2 , 250 Watt per channel .
17. ## Stereo Audio power amplifier 2 x 40W - 80W

HEre is a picture of heatsink
18. ## Stereo Audio power amplifier 2 x 40W - 80W

It is getting all in all expensive to build a sine wave inverter. Well Good news i will send some pictures of the heatsink i bought for the M250.
19. ## Stereo Audio power amplifier 2 x 40W - 80W

IF there are common connections . what will happen parallel voltage is same only current divides , and we have a lot of current no problemooo one car battery is about 55A @ 12V , the one which i have Here is an idea , what do you think
20. ## Stereo Audio power amplifier 2 x 40W - 80W

so if different channels are used can it produce more power
21. ## Stereo Audio power amplifier 2 x 40W - 80W

Well Thank God I got the Transistors at a low price , farnell is toooo expensive , i have bargained for Rs 1000 for 8 transistors , one transistors cost Rs 125 which is 1.25 pounds and 0.73 dollars i guess. so really low price. Well BEsides That i also have a 8 transisitor heatsink for only Rs 175 , which is 1.75 punds or 1 dollar approx. So I want to ask if this M250 can be used as a amplfier in the 500W inverter to increase power. and then use a power transformer afterwords..
22. ## Stereo Audio power amplifier 2 x 40W - 80W

i Have looked it up in farnell , i found the transistors by searching and selecting my country . My distributer is makkays , so i will be looking to contact makkays . However i glitch that makkays have these transistors on hand. if not they have to import . But still they cost around 5.5 pounds . which is approximatiley Rs 550 and it is really very expensice for a transisitor.
23. ## Stereo Audio power amplifier 2 x 40W - 80W

I Found something else also , the part number in the schematic i posted is MJE15024 and MJE 15025 which is wrong , it should be MJ15024 and MJ15025 , however MJE15030 and MJE15031 are correct numbers
24. ## Stereo Audio power amplifier 2 x 40W - 80W

There is a big problem , i asked my friend today and he says , MJE15024 and MJE15025 is not available here :-[ , can you please suggest a replacement
25. ## Stereo Audio power amplifier 2 x 40W - 80W

i have studyed just now that Class AB is about 79% efficient and Class A transformer coupled have 50% efficiency. However as far as the transformer is concerned , i have decided , a transformer of 2 x 38VAC @ 6A , with 2 x 12VDC @ 1 A for something(the other winding is seperate for from the first BUT IN THE SAME HOUSING) other then powering up a amplfier . i mean for the Detector circuits and the 10 band VU LED meter that i will insert in it . i will also need a bridge of 35A @ 230V , well i will begin in it later , seems like a tough project and a little expensive too . i will keep it as a mega audio project and now i will make the First Audio AMplfier i posted with PCB . i am going to draw a schematic and post it sooon. Wish me good luck in the exams , tommorow is my Solid state Devices and Basic Electrical Engineering paperz.
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