2 kwts discreet class d need help

[stewin]

you are lucky you've got parts available where you are. i am limited to irf540n/640/530/630 and irfp460/450/350/260/250n/240/150 irg4pc50u also fb23n20 those are the only available logical parts to be used . so i have to try to work within that limit

 

[norazmi]

Hi Dimonis,

thanks for the links, i already read it also done long time ago since 2008, but i believe u did more than me . At that time i hate many component involve to build amp, so i just look for simple amp to build. You`re always right Dimonis about choosing good mosfet with fast and good trr qrr ton toff etc.. i`ve no doubt about it and i have them with me such as irfb4227, irfb4229 irfb4020 etc, i`ve buy demo board from International Rectifier demo board Iraudump 7D from digikey i`ll post some picture here. I bought them because i want to learn, different ucd will give different sound..... I also done with IR2110 ucd and non ucd version, now going to build more simple one with lorylaci using HIP4080 chips. But u also give some opinion and suggestion here which is valuable to us , me, and others .

What Stewin means is maybe at hes place its hard or too expensive to get such good mosfet to run with class D. So maybe he choose old mosfet like IRFP250N, IRF540 and etc.. But i agree with u Dimonis, good amp come from good component so good mosfet is needed to get good quality. Board layout etc etc... lol .

regards,
Azmi.

 

[Dimonis]

you are lucky you've got parts available where you are. i am limited to irf540n/640/530/630 and irfp460/450/350/260/250n/240/150 irg4pc50u also fb23n20 those are the only available logical parts to be used . so i have to try to work within that limit

I see , sorry for you.

 

[stewin]

so dimonis a powerful schema which can use multiple parallel irfp250n. btw guys there are a lot commercial d hi power amps which use irfp250 in the output stage powersoft uses them in some of it's series

 

[Dimonis]

long time ago since 2008, but i believe u did more than me .

Probably no , i built my first Dclass amp about 2 years ago , and before this for a couple of years i only studied this theme.
Realy have'nt much time for DIY experiments:"::

HIP4080 a good idea , but it's expensive , and the supply of +-40V won't allow high power.

 

[Dimonis]

a lot commercial d hi power amps which use irfp250 in the output stage powersoft uses them in some of it's series

It's because they are cheap.
I don't produces commercial things::SD , i want a good amplifier with good or maybe even excellent sound for myselfwiz:;

 

[stewin]

It's because they are cheap.
I don't produces commercial things::SD , i want a good amplifier with good or maybe even excellent sound for myselfwiz:;[/QUOTE]

wow what about power like 2kwts rms at 8 ohms

 

[Dimonis]

wow what about power like 2kwts rms at 8 ohms

Sorry , didn't understand what you meant.

 

[norazmi]

hehe, lol he means that they use IRFP250N to provide 2kwrms of power. Lol Stewin please take a note, the amp u refer is maybe they use for the sub woofer, so u cant hear distortion or noise clearly because they only filter for low freq. What Dimonis want is high fidelity version, and we must accept with IRFP250N will have much thd when drive full range. so you guys i hope have win-win situation here oki

 

[norazmi]

one more, we must also take note, rms power output will be vary with load, 8 ohm, 4 ohm , 2 ohm and even 1 ohm. I have one monoblock with me, from Mohawk company they use IRFB4710 to provide 2kwrms at 1 ohm stable, i`ve use it with my 2 x 12 inch audiobahn subwoofer Q siries.

 

[norazmi]

iraudump 7D - 150

here is the picture, nice clean board from IoR

 

[Dimonis]

pretty
my DIY looks clumsy , but sounds fine :UP:.

 

[capsighter]

Nice Pics norazmi hows the sound..?

 

[norazmi]

Sound for me middle, avarage bass and mid , clear high. This package come with cd, inside they include everything even u can make new pcb exactly like Iraudamp 7, they include gerber, artwork, bom, sch file can be open with easy pc, reference guide and more... looks like we can send it to the pcb manufacturer to have another pcb. This is how IoR doing business and markerting to sell thier product by release working prototype first.

regards

 

[stewin]

how much does that kit cost + components? can they ship it in east africa especially iraudamp 9?

 

[stewin]

hi dimonis can you explain the below they use irfp264 to get 4kwt

http://www.diyaudio.com/forums/class-d/184954-gzpa-class-d-4000w-irfp264.html

 

[norazmi]

Stewin kits include and all has been mounted on pcb. last time im bought from digikey, idk if they have iraudump 9 kits, that time cost is about $300 usd. I think iraudump 9 will cost more than that. Stewin no worry about the kits lol, we did have discrete ucd working and for me its ok for the quality home made pwm, as we dont have such as sophisticated pcb solution at home, to improve discrete ucd there is another way to order pcb from manufacturer to have compact + smd + small, provide by component list, bom, gerber to them. and we need additional cost for it.

Did u try with totem pole 2 pair of mosfet? I did . Duty cycle will change accordingly, so thats why i`m asking to change R10 in ur schema with trimpot, its for future use. I`ll start making second pcb tomorrow to have it stereo. That amp with irfp264 4kwts at 1 ohm load. and its for sub woofer too.

 

[Dimonis]

hi dimonis can you explain the below they use irfp264 to get 4kwt

http://www.diyaudio.com/forums/class-d/184954-gzpa-class-d-4000w-irfp264.html

If they calculate the output like that - http://www.diyaudio.com/forums/class-d/154244-6000w-irs2092-35.html#post2942222 -why not.
My opinion - http://www.diyaudio.com/forums/class-d/154244-6000w-irs2092-36.html#post2942585
What frequency do they use?

 

[stewin]

Stewin, i know why is 12v zener there, if u refer to original phillips apps note, there is 4.7k resistor from positive rails which on your schematic is 33k, and 4.7k clamp with 12v zener to keep the voltage not over than 12v from positive supply rails. I`ve seen on hypex module similar to this they make separate 12v supply to hi and low side, like we can have aux using tip41c 2 pcs feed on each rails, so we no longer need 33k resistor on ur schema and 4.7k resistor on phillips ucd so we can avoid them both. also 12v zener can be avoid too.

so we have problem if we took 4.7k resistor clamp with 12v zener and by using tip41c to have aux 12v supply, so we have problem here, tip transistor will be blown because of hi current feed through 4.7k resistor, if u remove 12v zener without only, and aux supply at hi side will be more than 12v and will blown mosfet, then u take 33k resistor and i`ve measure that voltage is about 15v is acceptable. But its for max +/- 50vdc, if more than that the 33k resistor need to change or mosfet will blown again.

for my opinion to have enough current and stable at aux supply on each hi and low side we should mount 2 tips or even hinger voltage like MJE13005-007-009 for high voltage so we no longer need to care about 12v zener clamp and resistor change. and seems that this solution to be safe, i do simulation with this configuration and lets see how its going. If success i`ll do it experiment it in real life, because i do simulation with 33k res and without zener 12v is not enough aux supply on hi side, this will provide distort at high volume too.

regards

hi nozrami

i am nearly finishing the full bridge version but the transistor tip/mje for aux 1 is what i don't know how to add pls post a schema of driving aux 1&2 using transistors

 

[norazmi]

here is the modification for Stewin, remove R4 and D2, R38 and D13 and last D4 and D15. You can avoid them and the reason aux supply heats because of them. Without that components amp still working and its for startup only. if u put them at high rails, will cause aux transistor blown within 10 secs.

make same aux 12-13 v supply from negative rails, there will be 2 aux supply for each. and one supply connect to D3 and D10, and another one supply connect to D14 and D19.

So take a look at output stage u need to input 1uf caps 250v parallel with em, see my drawing for full bridge version. and make dummy load at output to ground about 3.3k 3 watts resistor. U also can put zobel network at output 15 ohm + 100nf caps to get nice high freq output, this is stated with iraudump 7D which they use zobel network too.

Change D5, D11, D16 and D20 with shcottky diode, 1N5819, SB160 or Bat64. Its very important to improve THD, or if u dont have it, u can put uf4004 @ mur120, but shcottky is better. If u want protection OCP which short circuit protection take it from ucd2.5 from RU, they work and i`ve tested it. i can give u OVP and UVP + OTP from iraudump 7D can be place together with this ucd.

draw it back, let me see if u get correct schematic.

regards.