I need to have a Bridge Rectifier 250V 40a ..... unfortunately there
is no such thing available as far as Google can see

Can anyone tell me what size Diodes that would work ? I am just a
hobbyiost and anything for instructions that I have found, look like
they need a College COurse to navigate.

Any suggestions or simple equation ?

thanks

Omicron wrote:
I need to have a Bridge Rectifier 250V 40a ..... unfortunately there
is no such thing available as far as Google can see

Can anyone tell me what size Diodes that would work ? I am just a
hobbyiost and anything for instructions that I have found, look like
they need a College COurse to navigate.

Any suggestions or simple equation ?

thanks

I assume that you're in the USA.
Mouser has some rectifier modules that will fill your needs. Go to
www.mouser.com.and search for part number GBPC4004 or GBPC4006. The
GBPC4004 unit is rated at 400V/40A, and the GBPC4006 is rated for 600V/40A.
Either will work for your application (assuming no major physical mounting
problems).
Mouser has no minimum order, and reasonable shipping rates (for shipments in
the USA).

--
David
dgminala at mediacombb dot net

"Omicron" wrote in message
...
I need to have a Bridge Rectifier 250V 40a ..... unfortunately there
is no such thing available as far as Google can see

Can anyone tell me what size Diodes that would work ? I am just a
hobbyiost and anything for instructions that I have found, look like
they need a College COurse to navigate.

Any suggestions or simple equation ?

thanks



http://uk.farnell.com/jsp/search/bro...06%2B1 004156

On Fri, 7 May 2010 19:51:54 +0100, Gareth Magennis wrote:
"Omicron" wrote in message:
I need to have a Bridge Rectifier 250V 40a ..... unfortunately there
is no such thing available as far as Google can see

Can anyone tell me what size Diodes that would work ? I am just a
hobbyiost and anything for instructions that I have found, look like
they need a College COurse to navigate.

Any suggestions or simple equation ?

http://uk.farnell.com/jsp/search/bro...004156+5056578
&Ntk=gensearch_001&Ntt=bridge+rectifier&Ntx=mode+m atchallpartial
&No=0&getResults=true&appliedparametrics=true&loca le=en_UK
&catalogId=&prevNValues=500006+1004156&filtersHidd en=false
&appliedHidden=false&originalQueryURL=%2Fjsp%2Fsea rch%2Fbrowse.jsp
%3FN%3D500006%2B1004156%26Ntk%3Dgensearch_001%26Nt t%3Dbridge%2Brectifier
%26Ntx%3Dmode%2Bmatchallpartial%26No%3D0%26getResu lts%3Dtrue
%26appliedparametrics%3Dtrue%26locale%3Den_UK%26ca talogId%3D
%26prevNValues%3D500006%2B1004156

"Simple" , indeed.

In article , Omicron wrote:
I need to have a Bridge Rectifier 250V 40a ..... unfortunately there
is no such thing available as far as Google can see

Can anyone tell me what size Diodes that would work ? I am just a
hobbyiost and anything for instructions that I have found, look like
they need a College COurse to navigate.

Any suggestions or simple equation ?

thanks


A bridge only works 1/2 cycle so you would need at least 20 amp
diodes. I don't know what voltage your at but
400 volts sounds pretty good to me.

Maybe two of each, NTE5920, NTE5921
Thats when you don't want to isolate the mounting from the heatsink, otherwise
just take your pick.

Bad example as far as COST !!!
I don't have time right now to shop.

You can also add diodes in parallel to gain amperage.
I found some 40 amp 400 volt bridges, but seem hard to find stocked items.

greg

On 5/7/2010 1:24 PM GregS spake thus:

In article
,
Omicron wrote:

I need to have a Bridge Rectifier 250V 40a ..... unfortunately
there is no such thing available as far as Google can see

Can anyone tell me what size Diodes that would work ? I am just a
hobbyiost and anything for instructions that I have found, look
like they need a College COurse to navigate.

Any suggestions or simple equation ?

A bridge only works 1/2 cycle so you would need at least 20 amp
diodes.

Huh? Where do you get that?

Despite only operating half-cycle, each diode gets the full current
flowing through it, so you need *at least* 40A diodes, better yet 40A.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

On 5/7/2010 2:14 PM David Nebenzahl spake thus:

Huh? Where do you get that?

Despite only operating half-cycle, each diode gets the full current
flowing through it, so you need *at least* 40A diodes, better yet 40A.

I meant to write "better yet *50A*".


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

On May 7, 9:46*am, Omicron wrote:
I need to have a Bridge Rectifier 250V 40a .....

Huh? That's a device that makes 10,000W of DC
power at relatively high voltage. It's not terribly SAFE
to do that; normal switches and fuses cannot
control such DC power. Is this for a flashing
strobe light to illuminate a stadium?

On May 7, 2:14*pm, David Nebenzahl wrote:
On 5/7/2010 1:24 PM GregS spake thus:

A bridge only works 1/2 cycle so you would need at least 20 amp
diodes.

Huh? Where do you get that?

Despite only operating half-cycle, each diode gets the full current
flowing through it, so you need *at least* 40A diodes, better yet [50A].

No, GregS is right. The rating of rectifiers is on the AVERAGE
current they pass (peaks can be much higher). The voltage
rating, for a bridge, has to be higher than the peak of the AC,
though, because there's a charged capacitor usually on the output.
So, a '250V 40A' bridge is made with 500V 20A rated diodes.

On 5/7/2010 2:24 PM whit3rd spake thus:

On May 7, 9:46 am, Omicron wrote:

I need to have a Bridge Rectifier 250V 40a .....

Huh? That's a device that makes 10,000W of DC
power at relatively high voltage. It's not terribly SAFE
to do that; normal switches and fuses cannot
control such DC power. Is this for a flashing
strobe light to illuminate a stadium?

Hmm; maybe it's for an arc welder. Although I guess those use low
voltage but lotsa current, so maybe not.


--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.

- Comment from an article on Antiwar.com (http://antiwar.com)

In article
,
whit3rd wrote:

On May 7, 9:46*am, Omicron wrote:
I need to have a Bridge Rectifier 250V 40a .....

Huh? That's a device that makes 10,000W of DC
power at relatively high voltage. It's not terribly SAFE
to do that; normal switches and fuses cannot
control such DC power. Is this for a flashing
strobe light to illuminate a stadium?

Whit-

Yes, 250 times 40 is 10,000. That doesn't mean the bridge is being used
to produce 10,000 watts.

Both voltage and current may represent peak values of a low duty-cycle
application. If the bridge feeds a capacitor filter, the voltage peaks
across any one of the diodes would be 2.83 times the AC RMS value. That
would be 88.3 VRMS in this case.

With a 2X margin, actual stress might be 44 VRMS and 20 Amps peak, or
880 Watts peak power. With a low duty cycle, it would be even less.
This wouldn't be unreasonable for many applications such as rapidly
charging the batteries in a hybrid automobile!

Fred

whit3rd wrote:
On May 7, 2:14?pm, David Nebenzahl wrote:
On 5/7/2010 1:24 PM GregS spake thus:

A bridge only works 1/2 cycle so you would need at least 20 amp
diodes.

Huh? Where do you get that?

Despite only operating half-cycle, each diode gets the full current
flowing through it, so you need *at least* 40A diodes, better yet [50A].

No, GregS is right. The rating of rectifiers is on the AVERAGE
current they pass (peaks can be much higher). The voltage
rating, for a bridge, has to be higher than the peak of the AC,
though, because there's a charged capacitor usually on the output.
So, a '250V 40A' bridge is made with 500V 20A rated diodes.

what about inrush current?

Here's what hammond manufacturing says

http://www.hammondmfg.com/pdf/5c007.pdf