Making a 2 Volt 400 Amp bridge rectifier?

[BoyntonStu]

The 400CNQ center tap, high current, Schottky rectifier
module series has been optimized for very low forward
voltage drop, with moderate leakage. The proprietary barrier
technology allows for reliable operation up to 150 °C junction
temperature.

The cathode base is common.

How do you use 4 of these with respect to heat sink mounting and
electrical isolation?

 

[BoyntonStu]

That part is not normally intended to be used as part of a
bridge, but for a half bridge (center tap of a winding as
the negative output, common cathode as positive output)
rectifier. I also know of no standard way to isolate the
common cathode mounting bar from the heat sink. If I had 4
of these and had to make a bridge, I would connect each pair
of diodes in parallel (use each unit as one rectifier) and
mount them on 4 electrically isolated heat sinks.

John,

4 isolated heat sinks is a reasonable solution.

A fan wouldn't hurt.

Any Shottkey 400 Amp bridges available for less than a tank of gas?

Or a better way?

BoyntonStu

 

[BoyntonStu]

That depends on how much current you push through those 400
amp rated diodes and how large the heat sinks are.


Not to my knowledge.


Look for doubler configuration diodes (connected in series,
cathode to anode), instead of common cathode. Two of those
can be used to make a bridge by connecting the AC to the
common nodes and tying the cathode ends together as positive
output and anodes together as negative output. Only two
isolated heat sinks needed.

I.e. (though not a Schottky:http://cgi.ebay.com/1-UNIT-P-N-TDM30012D-BY-MICROSEMI-Dual-Diode-Doub...

John,

At 400 Amps I believe that the power dissipation would be too much in
a non-Shottkey rectifier.

Also, the forward voltage drop is a major consideration at such low
voltages.

Also, my intention is to supply 1-1/2 Volts DC at 400 Amps and I would
need to wind additional high current carrying cables around the
xformer core to make the output higher.

What kind and value smoothing cap would you recommend and ditto
bleeder resistor?

 

[BoyntonStu]

I agree. I was not recommending that device, just using it
as an example of the doubler configuration.


No kidding!


Have you considered winding a center tapped output so you
can use just two diodes (or your original part)? At this
voltage and current, synchronous rectifiers made of large
MOSFETs with a separate gate drive winding might be a lot
better.


What is the frequency? An inductor filter may work better.
--
Regards,

John Popelish

What is the frequency? An inductor filter may work better.

It's for electrolysis. Frequency?

Thanks