sammyb11

I am looking for a single phase rectifier with a blocking voltage of at least 30V, current rating of 300A or greater, and a forward voltage of .25V or less. Does anyone know where I could find something like this or if they even exist?

Sam

dknguyen

What are you trying to do? Because no one runs 300A at 30V. You run it at 300V at 30A to reduce the current which reduces the losses.

Is this 300A continuous? Or stall? Because if it's continuous, then what I said above applies. If it's stall, then you need the continuous rating.

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ronsimpson

SPB16080 & DSS2x110-80A Schottky dual 160 amp. Will not do 0.25 volts!

300U5A, 300U5AMA, 300U5AM 300A 50 VOLT (Vishay IR)
306CNQ200
SPB160100E3 (Microsemi)

I do not see anything that will make the 0.25 volts! At these current levels you should try MOSFETs used as diodes.

IRF2804strl7pp 40 volt 320 amp 1.6mohm (you will need to parallel two to get you forward voltage spec.)

IRF1324S 24V 429A 1mOHM

sammyb11

I am trying to run a high current, low voltage electrode. The 300A is continuous. I have noticed that not many people run at these levels, otherwise this component would be easier to find.

dknguyen

THat tells us absolutely nothing. What are you trying to do? Not how are you trying to do it, but *what*. You may be going about it the wrong way (which is usually the case when someone has seemingly outrageous requirements).

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Torben

Wild guess: homemade welder?


Torben

Nigel Goodwin

Well, yet again he's not got his location filled in, but 300A at 30V is 9000W, three times what you can get from a normal single phase socket in the UK.

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Torben

And a few hundred more than you get from a Canadian dryer plug which we use for bigger welders. Maybe he has a big genny.


Torben

Boncuk

You can do it using an active rectifier.

An active rectifier works with power MosFets which you can parallel to obtain the desired current at very minimal losses, well below 0.1V per "diode".

I have experimented with an active bridge rectifier using N and P-channel power MosFets. The circuit worked, but not to my satisfaction. The problem is: N and P-channel MosFets have different RDSON values which makes it almost impossible to obtain a safe rectified voltage. One transistor out of tolerance causes huge shorts switching N and P simultaneously. (just half way is enough for St. Elmo's fire. )

A two-way rectifier doesn't have those problems. The circuit is going to be published in Elektor magazine in July/August 2008.

Give me PM and you might get the circuit in advance.

Best regards

Hans

electronic spark

Why not parallel 3 >100A silicon rectifier diodes?

carmusic

does active rectifier with mosfet exist in single chip replacing classic bridge diode, i would need approx 50A capacity at 30V?

gerty

300a diodes are used in battery chargers for forklift . The batteries I'm referring to are 48 volt and weigh in at about 3,000 lbs, don't remember the a/h capacity..The primaries of the chargers are fused 30a at 480volts.. Not sure of the voltage rating of the diodes either, probably 200 or so. We purchased replacements from the manufacturer, are they were 75 miles down the road from us (Clarklift of Middle Tenn.). I'm sure they weren't cheap either, as none of thier parts were..

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sammyb11

What I am trying to do is take 300A at 30V AC and turn it into DC while minimizing voltage drop. I've been told that a gallium rectifier has a forward drop of 0.35V but they are expensive. That could work if I can find one. Another option could be a selenium rectifier. Does anyone know what the forward drop on a selenium rectifier is?

Nigel Goodwin

Seriously old antiques! - and from what I remember the voltage drop is a LOT more than a silicon rectifier - for a 300V rectifer probably 20V to 50V?, so about 10% of that for 30V.

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Boncuk

Not that I know of, but it certainly is desireable.