Re: gEDA-user: [OFF] high current amplifier

[Levente Kovacs <leventelist@xxxxxxxxx>]

Ok,


I guess I wasn't clear, so I have to add that it won't be used to drive a
speaker, I used the word "audio" to refer the frequency range. 500W audio
amplifier that designed to drive 4-8 Ohms is easy. But 100A, is something you
won't get in a pro audio store. The coldamp design provides 25Amps. So the
easy solution would be to convince my manager that 25Amps is quite enough for
us... :-)

I think I can connect power MOSFETs parallel, and they might put that current
out. The important thing is to charge and discharge the gate capacitances. I
too thinking in class-D solution.

I think your digital amp is not what one calls class-D amplifier. Or do I get
something wrong?

I think the problem is not that it should provide 500W, rather 100Amps.

Anyways, thanks for your thoughts.

On Wed, 20 May 2009 09:19:43 -0500
John Griessen <john@xxxxxxxxxxxxxx> wrote:

> Levente wrote:
> > Hi,
> > 
> > 
> > I have to design an audio amplifier that can deliver 100Amps. It
> > should work around 50Hz, and the maximum output power shall be
> > 500W. I am currently reading articles about this topic, but it is
> > very hard to find things like this. If someone has some experience
> > with, or some documentation of high current amplifiers, please
> > share it.
> 
> Sounds like a fog horn driver.  Your best bet will be a "digital amp",
> or in other words a sigma delta DAC with the speaker coil and some
> capacitance in the feedback loop.  An example would be: a train of
> 2-bit plus sign data is converted into analog levels 0 +1 +2 -1 -2
> Volts and the analog level on the speaker coil and cap. is fed back
> into the DAC to a fast ADC stage so it can combine with the
> datastream inside the sigma delta converter.  The low pass filter
> that loses all the choppy back and forth of the drive data levels is
> the cap. and speaker coil itself.
> 
> This is the highest efficiency type of driver since it's driving
> transistors are never in active region -- always full on or off. High
> efficiency is what you need to put out 500W.
> 
> John
> -- 
> Ecosensory   Austin TX
> 
> 
> _______________________________________________
> geda-user mailing list
> geda-user@xxxxxxxxxxxxxx
> http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
> 


-- 
Levente Kovacs
http://logonex.eu



_______________________________________________
geda-user mailing list
geda-user@xxxxxxxxxxxxxx
http://www.seul.org/cgi-bin/mailman/listinfo/geda-user