UCD 25 watts to 1200 watts using 2 mosfets

[ChocoHolic]

You guys are throwing formulas around - show me where they come from please. As far as I know rms of power is simply sqrt(2)/2 or 0.707 times the peak power. Let's assume 1 kHz sine wave which is how power is specified as usually. Half bridge full bridge - why is that even a consideration for an amp that is making a sine wave audio signal. We are not talking about AC line power and power factors are we?

Here is the reference for RMS Power from TI for class D amps.

Using their equation on page 4 I get 8kW still.

http://www.ti.com/lit/an/slea047a/slea047a.pdf

Peak current is 180 volts /2 ohms = 90 amps. 90 amps x 0.707 = 63.6 amps. 63.6 amps ^2 x 2 ohms = 8kW.

180Vpeak would be the value in case of a full bridge or bridged operation of two half bridges.
From a single half bridge running with +/-90V you will only get 90Vpeak, because one end of the speaker is tied to the zero volts, means tied to the middle of the rails.
So you will just get half the current of your calculation, means 1/4 of your calculated power.

And even this is perfectly blue eyed, because you have to assume the sagging of the rails and additionally a few volts drop in the amp.

 

[DC sound]

Hi Nano
greetings NICE WORK
warm regards
andrew lebon

Hi Andrew,

can i ask for PCB lay-out or any files for this amps below..
kindly send to my e.mail. danicaser@yahoo.com.ph

thanks...

 

[alfonsa]

My Inductor is very hot, why it happen?

 

[29285]

Normally this happens when the toroid consists of poor quality iron powder.
Even without audio signal, the high frequency ripple current creates enough core loss to heat up the core.
For that reason I prefer gapped ferrite cores.

 

[stewin]

hi volt wide how many turns do you use for irs900d also the gap you set to how many millimeter

 

[stewin]

???? ?

 

[alfonsa]

can I use gapped ferrite core from PC PSU or another PSU (like Televison PSU), because I can't find gapped ferrite core in my place

thanks

 

[alfonsa]

Normally this happens when the toroid consists of poor quality iron powder.
Even without audio signal, the high frequency ripple current creates enough core loss to heat up the core.
For that reason I prefer gapped ferrite cores.

can I use gapped ferrite cores from PC PSU or another PSU (like Televison PSU)
because I can't find gapped ferrite cores in my place

thanks

 

[lithoc]

Not sure if anyone notice there's a new IRS20965 driver just released
It have higher gate drive


IR Introduces Class D Audio Chipset Featuring the IRS20965 Driver IC with Protected PWM Switching for High Performance Audio Amplifiers

 

[29285]

can I use gapped ferrite core from PC PSU or another PSU (like Televison PSU), because I can't find gapped ferrite core in my place

thanks

Sorry for me answering that late.
Yes, you can use recycled gapped cores of PSU like EE-cores, EC-cores and the likes if you do not mind these might be more bulky than necessary.
If you give me the core-size available to you, and the supply voltage and operating frequency of your d-amp, I could give you a rough estimate of the windings required.

 

[apexaudio]

My Inductor is very hot, why it happen?
View attachment 415129

Is this amp APEX D200 from my thread?
http://www.diyaudio.com/forums/class-d/182900-class-d-amp-lm566-lm393-2xirf530-56.html

 

[alfonsa]

yes sir, my class D amplifier from your schematic, nothing change. it is work. I will replace my inductor with gapped ferrite cores.

 

[alfonsa]

I have one from Television PSU, the size 3,5 cm x 4 cm x 1 cm. operating frequency of my d-amp 400 Khz. with supply +- 70 Volt. thank you sir, for your help

 

[JOHN BALI]

Hi Alfonsa,
I have some the "red core"
is the T-130-2 suitable for this class D?

 

[ionutzxpo]

Hi john, its more than perfect!

 

[alfonsa]

I have one from Television PSU, the size 3,5 cm x 4 cm x 1 cm. operating frequency of my d-amp 400 Khz. with supply +- 70 Volt. thank you sir, for your help

Hi JohnBali, I think, it's perfect for class D

 

[stewin]

hi all a preview of up coming project . i got hold of some smd components i will use one pair of irfb 4227 and i want to use +/-72 volts . i wanted to drive the amp up to 1ohm load . any comments or ideas are highly acceptable and welcomed.

 

[andrewlebon]

Hi Steven
greetings 1 ohm load on 1 pair mosfets
warm regards
andrew

 

[stewin]

irfb4227 have over 60amps ratings

 

[ionutzxpo]

for 2 ohm is ok for 1 is a no go for me, better use +/-60V and the more robust IRFB4321 a friend of mine tested it at 1 ohm load with 60V and worked flawless

cheers