Maker Pro
Maker Pro

Question about full wave bridge diode

T

The Proud Infidel

Jan 1, 1970
0
I just got done rewinding the secondary on a simple battery charger. Now it
puts out more amps than the full wave bridge will handle. I am using a radio
shack 25 amp 36 volt full wave bridge and the transformer will put out about
30 or 35 amps. This is the biggest full wave bridge they have in stock.
Anything bigger means I have to travel a long way and pay a lot more money.

My question is this, Can I use two bridges in parallel to handle a higher
amperage?
 
B

bushbadee

Jan 1, 1970
0
It would be simpler to just not use the power supply at full rated power.of
the transformer, which you do not really want to do any way.
If you try to use parrellel diodes near their limit one will get hotter than
the other and hog the current and possible fail.
 
T

The Proud Infidel

Jan 1, 1970
0
That kind of beats the purpose of rewinding the transformer in the first
place. I have a hydrgen generator that I am working on and trying to put
through some reliability and life expectancy tests. It draws nearley 25 amps
and after 40 hours it blew my 25 amp diod and cooked the inductor.. After
rewinding the transformer with #10 wire it blew it in a about a minute or
so. The fact that it lasted that long tells me that it is not producing much
more than the 25 amps so I wouldn't be paralleling them near their limit.
That is why I was considering paralleling them.

I know you can parallel the transformers because I used to have an arc
welder I built out of rewound microwave oven transformers like this one and
paralleled them to increase the amperage. That is where I got the idea of
paralleling the diod.
 
S

sQuick

Jan 1, 1970
0
The Proud Infidel said:
I just got done rewinding the secondary on a simple battery charger. Now it
puts out more amps than the full wave bridge will handle. I am using a radio
shack 25 amp 36 volt full wave bridge and the transformer will put out about
30 or 35 amps. This is the biggest full wave bridge they have in stock.
Anything bigger means I have to travel a long way and pay a lot more money.

My question is this, Can I use two bridges in parallel to handle a higher
amperage?

Make one out of four diodes, A quick search sees that
a NTE5990 will do around the 45A mark and I believe
they are about $4.
 
S

Spehro Pefhany

Jan 1, 1970
0
Make one out of four diodes, A quick search sees that
a NTE5990 will do around the 45A mark and I believe
they are about $4.

Or, the Microsemi MP504W (P/N MP504WMS-ND from Digikey) is rated at
50A/400V and is only $6.40 ea. one-off. It needs an appropriate heat
sink.

Best regards,
Spehro Pefhany
 
T

The Proud Infidel

Jan 1, 1970
0
Thanks to both of you for the quick answer. I will check therm both out.


Spehro Pefhany said:
Or, the Microsemi MP504W (P/N MP504WMS-ND from Digikey) is rated at
50A/400V and is only $6.40 ea. one-off. It needs an appropriate heat
sink.

Best regards,
Spehro Pefhany
http://www.speff.com
 
B

bushbadee

Jan 1, 1970
0
Here is a suggestion.

Get Motorola auto diodes.
I used them in a high power converter I built way back in 1970
They are capable of very high currents, are cheap and at the time were the
fastest powr diodes on the market although they were not advertised as such.

Have you checked them out.
 
T

The Proud Infidel

Jan 1, 1970
0
bushbadee said:
Here is a suggestion.

Get Motorola auto diodes.
I used them in a high power converter I built way back in 1970
They are capable of very high currents, are cheap and at the time were the
fastest powr diodes on the market although they were not advertised as such.

Have you checked them out.

No I have not even thought about them, however I most certainly will and
keep that in mind for future reference.

I did finally find a larger full wave bridge which is now working quite
well. I wish I had known about this sooner because I have several 100 amp
alternators in the shop I could have gotten them from.

Thanks again for the suggestion.
 
Top