Development of a 10W class D

[poetanegro]

Hello gentleman! I'm looking for a simple design to mount or some help to develop a class D amp... I was looking for simple solutions as a 555 based class D, but nothing was conclusive enought to risk a mounting.

I've been working around some circuits that i've found over the forum related to what i want.

The one i'm looking right now.

http://www.diyaudio.com/forums/atta...65653410-10w-class-d-amplifier-design-10w.jpg

My first doubt about it is because i've simulated the square wave agains the passive low pass filter, and it just turn into a triangular wave if the square wave is simetrical (top +, bottom -)

That frustrates me, means i can't buid a 555 timer based for the 500khz square carrier? I'm looking for single supply applications right now, but if needs, i've a transformer 12+12 3Amps that i can arrange a +-15v or something.

I need some advise about it, cause i'll work around some simulations before go out to actually protoboard it (here at my city is a hard job to find electronics, and a hard "trip" as well)

 

[Tekko]

Why not make it self oscillating ? I built a class d around a TC4422 that was a self oscillating delta sigma type class d.

 

[poetanegro]

do u have the schematic? and what's delta sigma?

 

[Sch3mat1c]

This works pretty well,
http://t3sl4.dnsdynamic.net/Class_D_Amp.pdf
Excuse the messy schematic, the board looks much nicer.

Tim

 

[poetanegro]

I see... But it is a little complex for me... There's no other simple, conceptual, easy-to-find components circuit? I'm asking for a 10/15W amplifier, doesn't need more..

 

[Tekko]

This is the circuit i developed around a gate drive ic some years ago: http://diymania.hv4all.com/selfosc classd/new/MCD/stereo/MHzdampschvalues2.jpg

Here it is recreated, in bridgemode: Self oscillating class D - YouTube

 

[poetanegro]

Tekko, Could u explain to me how it works? the first part i can see an inverter sngle-supplied amplifier, almost 2 of gain, pratically a buffer. Can't see why isn't decoupled at the output.

And the second one i'm totally lost.