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 <[email protected]> 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 > [email protected] > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > -- Levente Kovacs http://logonex.eu _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
