BIG Amps Competition!

pfly wrote: Am I wrong when I'm thinking of PKN making use of 3 phase supply properly, it should be 3*32A*400V = 38400W going in. Also on top of that the condensor banks need not be anywhere near as big as with single phase since the three phases pretty much rectify the supply already? Someone please correct me.

Yup, you will get 300Hz ripple at 50Hz supply frequency from a 3 phase input full wave rectified to a single DC supply.

You still need Smoothing Caps but their capacity can be reduced pro rata in terms of the required stored charge compared with single Phase supplies.

Have built a number of 3 Phase input high current DC supplies for industrial use; the downside is requiring three transformers plus rectifiers, but the output Current rating can be very much improved with the increase in ripple frequency as well as the reduced loading of each of the three transformers.
For direct off line DC supplies feeding into Switch-mode PSU's the same applies, but without the need for transformers.

hope this answers you, loads more on this in PSU design Papers published on't 'net
Mik


Edited by audiomik - 16 March 2012 at 11:48pm

pfly wrote: Am I wrong when I'm thinking of PKN making use of 3 phase supply properly, it should be 3*32A*400V = 38400W going in. Also on top of that the condensor banks need not be anywhere near as big as with single phase since the three phases pretty much rectify the supply already? Someone please correct me.

I think the original equation is correct. Remember that the usable voltage will be (root3)*400V, so:

  Power Available =  3*32*400/(root3)

                            =  (root3)*32*400

Or have I missed something there?

"4800w/14800w=0.32"

What does this mean?
Is this efficiency of the amp in turning mains power into output power?

pfly wrote: Am I wrong when I'm thinking of PKN making use of 3 phase supply properly, it should be 3*32A*400V = 38400W going in. Also on top of that the condensor banks need not be anywhere near as big as with single phase since the three phases pretty much rectify the supply already? Someone please correct me.

The three phased power is:  Suare Root of 3 * 32A * 400V = 1.772 * 32 * 400 = 22170W if the power factor is close to 1.
Most of PKN amps have Power Factor close to 1 anyways.
I do not want to comment the other amps however this power value in our case represents what average scaling of the power distribution system required to operate this amp close to its maximum power with "normal loads" and dense but "normal music signals" :-) . It does not mean that the amp would not pull out more from the AC line if needed but the typical circuit breakers have this capacity for extra current for few seconds.

how on earth can you fit 40K into a box that small?

Sounds like you've got more chance of frying your speakers if something goes wrong