Connecting 2 bridge rectrifier

[Pocoyo]

Hi, advice needed

i got a question

1.
How to connect transformer 27vac - 0 - 27vac to get 54vac - 0
is there alright if i connect 27vac & 27vac (than i get to 54vac) ?
or there is a better way ?

2.
from this single transformer ( after i get 54v - 0 )
i want to connect with to 2 psu.
can i use 2 bridge rectrifier there

can i connect like this (below) ?
or there is a better way ?

................. + ................................. + .................
0.....~ ........1..........~ ------ ~ ..........2.........~ ...54
..................-....................................-..................

or i must connect like this

................. + ................................. + .................
27....~.........1..........~ ------ ~ ..........2.........~...27
..................-....................................-..................

1 = First bridge rectrifier
2 = second bridge rectrifier
----- = jumper the bridge rectrifier

i really dont know bout this
please help me

[Pocoyo]

for the picture 2
where 0 must connect ?

................. + ................................. + .................
27....~.........1..........~ ------ ~ ..........2.........~...27
..................-....................................-..................

please help me

[Pocoyo]

Which Better
to connect 2 psu with 1 bridge rectrifier or 2 bridge rectrifier ?

[pacificblue]

Originally Posted by Pocoyo

How to connect transformer 27vac - 0 - 27vac to get 54vac - 0
is there alright if i connect 27vac & 27vac (than i get to 54vac) ?

Yes.

Originally Posted by Pocoyo

or there is a better way ?

No, there is only one way to do it.

Originally Posted by Pocoyo

from this single transformer ( after i get 54v - 0 )
i want to connect with to 2 psu.
can i use 2 bridge rectrifier there

None of your drawings will work. The rectifiers must be in parallel on the AC side, not in series.
If you want to get 2 separate DC circuits, 2 rectifiers have a slight theroretical advantage. In practice you won't notice much difference. If you want to connect the DC rails together again, the way it looks in your schematic, 1 rectifier is better.

[Pocoyo]

Originally Posted by pacificblue

Yes.


No, there is only one way to do it.


None of your drawings will work. The rectifiers must be in parallel on the AC side, not in series.
If you want to get 2 separate DC circuits, 2 rectifiers have a slight theroretical advantage. In practice you won't notice much difference. If you want to connect the DC rails together again, the way it looks in your schematic, 1 rectifier is better.

Thanks for your advice pacific blue

1
i will connect 27v with 27v to get 54v

2
Yes i want to get 2 separate dc circuit
my friend use one rectrifier and get hummm
i will try like this

................. + ................................. + .................
0......~......Rec1..........~ ------ ~ .....Rec2.....~ ....54
..................-....................................-..................

Thanks once again pacific blue
Best regards, jeffry

[pacificblue]

Two rectifiers will probably not solve the hum issue, because you have to connect both V- to GND.