35a or 40a bridge rectifier what is the difference

[brianschanafelt]

i have a 40a 600v bridge rectifier but it calls for a 35a 600v. what is the downfall  if i have five more amps over the specified 35a    thanks

[ve6aym]

Hi,

Actually your better off with the 40 amp..if its rated at 35 amp in your project.Less chance of a burnout..just dont put an underrated bridge in your circuit

[wpowokal]

And if you search you will find much discussion/advice on not running bridge rectifiers at their rated current without significant heatsinking and possibly cooling fan.

allan down under

[Bruce S]

Actually; you may want to make sure the rest of the circuit can handle the extra rating. It's kind of like going over the 20Amp rating of a switch, over it and you could end up heating the wires, the circuit board, etc.

I most likely work with no problem as is, but if its to be used with a windmill circuit and the extra amperage goes downline and something else gets over heated up???

Caution is the word:-)

Bruce S

[commanda]

if its to be used with a windmill circuit and the extra amperage goes downline

Using a higher rated diode bridge will not magically create any "Extra Amperage".

Amanda

[Bruce S]

VERY VERY true,

but if for some reason, high wind, freak micro-bursts ....then the extra current coming in could be there.

I leave magic to the illiusionists:-)

, the worry I would have would be to have a point that could possibly over load the rest of the circuit.

Cheers

Bruce S

[ve6aym]

Hi again,

That 40 amp bridge will just sit there and do its thing..like the 35 amp bridge, it will even pass current at 50 and 60 amps....but not for long...s

It is up to the designer of the circuit to make sure they employ proper current limiting techniques and take appropriate steps to shut down the bridge if large surges

last any length of time..as I assume in this case, that the limit is 35 amp..

putting in a 40 amp bridge versus a 35 amp bridge should do no harm except give you more protection..

There, I said my big words for the year..now I can go back to my rocking chair and drool at the mouth like a good little senior..

[brianschanafelt]

thank u

 i was given the 40a from a good friend so i was hoping of only having to buy two more 40a instead of five 35a  

[laskey]

Now wait a minute here.... The math isn't right. If you were supposed to use five 35 amp bridges (I assume in parralle) that is 175 Amps, that is not even close to being equal to the 120 amps of three 40 amp bridges.  You'd better check that before you go ahead.  You can certainly sub in five 40A for the  five 35A, but I'd be careful about removing bridges.   I had an old electronic professor that used to say "components are cheap, don't be stingie!"  (well... it sounded better in an Italian accent)  Also when you got that kind of current, you'd better have a big heatsink.

Cya,

Chris

[brianschanafelt]

i am going to have five rectifiers in a row that is two hundred amps. i think that is way over enough with some to spare.