inrush current

[Adrculda]

My setup has changed slightly, but will still need a soft start.
I have TWO ANTEK AN10440 ( 40VAC @ 25A ) with 4 power boards
On each main rail boards are setup on a CCRC principle.
AC -Rectifiers - 2x Main Cap - 4x Resistor - 1x Main cap - 1x De-coupling cap- DC OUT
Each board has both rails on it.

Rectifiers are MBR40250 ( 250V 40A Schottky's )
Main caps are 15000uF 63V Chemi-Con KMH
De-coupling caps are 0.1uF 400V Vishay Film caps
Resistors are 4W 5% Dale Wire Wound / Non-inductive.

Guestimating Output ~56VDC @ 50A on BOTH rails 😱

Pics Below...

An externally hosted image should be here but it was not working when we last tested it.

 

[djk]

MBR40250 Ifsm=150A

http://www.onsemi.com/pub_link/Collateral/MBR40250-D.PDF

An ordinary 6A rectifier has an Ifsm=400A rating, so fast rectifiers need inrush limiting more so than ordinary rectifiers.

http://www.onsemi.com/pub_link/Collateral/MR750-D.PDF

 

[Adrculda]

Thanks for the heads up...
Hence more of a reason why to use a something along the line of a PWM limiter until 30% of rail operating voltage is achieved.

Now wondering....
What the 110V 50A output to the speakers would sound like 😱

 

[Adrculda]

110V 50A output to the speakers would sound like 😱

Just realized Antek test torroids with secondaries in parallel...
So it's 12.5A per secondary coil or 25A for both coils.

Quick math...

40VAC x 1.4 = 56VDC to each rail at 12.5A per toroid

Rail to Rail I should see 112VDC @ 12.5A on each. 🙂

 

[Ametherm]

Send me a message if you are still having difficulty