MUR860 Full Bridge Rectifier

[Einric]

How would a full wave bridge rectifier made from naked MUR860's stack up against a standard 35A potted Full Wave Bridge Rectifier?

 

[ticknpop]

Mur 860 is only good for 8 amps. If it's a high power 100 watts or more power amp with big 22,000 uf caps or more then you want higher current rated diodes
IR has some nice 25 amp hexfets ( and 60 amps). Harris, Fairchild, etc

 

[Triodethom]

How would a full wave bridge rectifier made from naked MUR860's stack up against a standard 35A potted Full Wave Bridge Rectifier?

There are some question before that can be answered . 1. how big is the current requirement . 2. how big the first cap. 3. What curcuit do you want to power.

 

[Einric]

Well this will be for a Pass F4.
I will be using the DIY Audio pcb's and running about 1.5A of bias.
The first cap will be 2 15kuF in parallel followed by .11R then 3 15kuF in parallel.

 

[Einric]

Someone had suggested I use Schottky Rectifiers instead of the MUR860.
Would something like this be more suitable?

 

[Triodethom]

Someone had suggested I use Schottky Rectifiers instead of the MUR860.
Would something like this be more suitable?

try
STPS30100ST STPS30100ST STMicroelectronics | Mouser

That has a 100 volt version .

 

[Einric]

I see that one also has two anodes that are electrically common.
And it's cheaper!
It just has a higher forward voltage drop.

 

[Triodethom]

for this 30a and keep your piv up and you are there as far as I can see then use good caps.

 

[Einric]

I will be using Cornell Dubliner SLP 15000uF 25V 105deg. in a 2-R-3 per rail.

 

[Robert Kesh]

I will be using Cornell Dubliner SLP 15000uF 25V 105deg. in a 2-R-3 per rail.

Isn't 25V a little too close to the supply voltage for comfort? Especially before the R.

 

[Einric]

18V secondary would give about 24.5V after rectifier voltage drop.
I will be using good quality high temp capacitors at their rated voltage well below their temperature rating.
Nelson Pass F4 power supply schematic shows 18V secondaries and 25V caps.

 

[jtl1]

Do not use Schottky diodes in this application -- they aren't meant for it, and it will bite you (Very low breakdown voltages, and the fast switching speed will cause noise). I suggest simply going with a good old fashioned potted can -- they are indestructible, match thermally inside due to their construction, and are heatsinkable, unlike individual diodes.

 

[Robert Kesh]

18V secondary would give about 24.5V after rectifier voltage drop.

Until your mains supply runs over its rating. Mine consistently runs at 15% above here.

But Pass must know what he's doing.

 

[Einric]

The caps have a 32V surge limit and the power here in my area runs a consistent 115V.

I was looking at some TO-220 heatsinks for the rectifier diodes.
Are their any 35A Ultrafast potted rectifier packages out there?