Does this two circuit have the same output?

[motbuddy]

27052010589.jpg

Actually i want to combine this two circuit(above part) by using only one center tap transformer. At the beginning i'm using two type of transformers but now i want to combine it to become using one type of transformer to save down one transformer. So instead of using one 24-0 and one 12-0-12 transformer i combine it together by just using one 24-0-24 center tap transformer as shown at the bottom part.

Does my circuit correct to get the final output voltage as the upper part?

thank you

[AndrewT]

a single secondary cannot easily give a dual polarity supply.
A dual secondary or a centre tapped secondary both give a dual polarity supply.

The 24-0-24Vac could give a very high voltage at the smoothing caps, maybe as high as +-40Vdc.
This may overload the 7x12 regulators.

[motbuddy]

ok.so do u have any idea on how to get the final output voltage but just using one transformer?

thank you.

[AndrewT]

centre tapped secondary of 24-0-24Vac as you have proposed.
Take a dual polarity supply from the main PSU and drop the voltage using a tracking pre-regulator based on an LM317 (+ve) and LM337 (-ve).
This pre regulator arranges for the next series regulator (LM78xx & 79xx) to always see an adequate voltage to never drop out while good mains is available and the tracking part ensures that the series regulator never sees a voltage at it's input that is greater than maximum rating.

That's a total of just 4off 3pin regulator ICs.

[motbuddy]

hi,
As i refer to Power Supply for Power Amplifiers
p04_fig1.gif

My connection is almost same as his design to have dual power supply. So can my circuit works?

27052010589.jpg

thank you.

[star882]

It will work fine. (Although two diodes in the upper bridge do not serve any useful purpose and can be omitted.)

[motbuddy]

Originally Posted by star882

It will work fine. (Although two diodes in the upper bridge do not serve any useful purpose and can be omitted.)

thanks for the reply.
So as refer to the paper i posted up.the left upper part output to my circuit A. I just wonder that,does the circuit at the bottom part which also output to the circuit A has the same output voltage as the upper part? Because i had change the transformer from a 24-0 to a 24-0-24 and the connection has changed too.

thank you.

[star882]

Yes, that's how it works.

[motbuddy]

if my circuits need around 1A.Can i use a 2A transformer?

thank you.

[star882]

Yes.