Does this two circuit have the same output?

Thread Starter

simpsonss

Joined Jul 8, 2008
173
hi,

I'm confuse about using this two type of transformer to get the same output voltage.
Does the two circuit below have the same output voltage?

27052010585.jpg

thank you.
 

SgtWookie

Joined Jul 17, 2007
22,230
The lower circuit is not drawn correctly.

The ground output needs to come from the left side of the bridge, like the top - not the bottom.

If the correction were made, then yes - the output voltage under no load would be the same.
 

Thread Starter

simpsonss

Joined Jul 8, 2008
173
Actually i want to combine this two circuit by using only one center tap transformer. At first i'm using two type of transformer but now i want to combine it to become using one type of transformer. Any idea?

27052010587.jpg

thank you.
 

SgtWookie

Joined Jul 17, 2007
22,230
I meant that the circuit you posted (the right side of the image) in my last reply will work.

You need to give some more specifics, such as the transformer rating. If it is not rated for sufficient current or wattage, your output will not be what you might expect.
 

Thread Starter

simpsonss

Joined Jul 8, 2008
173
sorry just to make things clearer, i make a summary for the circuits.

So the above and below have the same output voltage right? For the Amp i need for my circuit will be enough because my transformer is a 1A rating, and my circuits will just need less than 1A. The more thing i concern about is whether i could combine the two circuits become just using one 24-0-24 transformer to save down one transformer.

Does the circuit at the bottom part of that paper work in the same way as the above part?

27052010589.jpg
 

Thread Starter

simpsonss

Joined Jul 8, 2008
173
What voltage do you want output?

You have not yet mentioned that. Shall I simply make guesses?
ok. my circuits need 3 voltage output.
1. I need a Vpeak of ~30V, so i decided to use a 24-0 transformer.
2. then, i need positive 12V and negative 12 voltage for my circuit too.

Any idea?

thank you.
 

SgtWookie

Joined Jul 17, 2007
22,230
I don't know what your current requirements are. With a 24v input transformer, your 30v output will have a good bit of ripple on it.

Anyway, here's what you need to do:



The outputs will not be regulated. You will need to add regulators to achieve a relatively stable voltage output. It will not be possible to suggest capacitor values unless you suggest what the maximum load current will be.

You must use a fuse on the input. It can be a slow-blow fuse, but a fuse must be present. This will protect everything past the fuse from overload. If you do not use a fuse, your project may quickly go up in smoke. The fuse must be in the line voltage side of the circuit.

The power switch S1 is optional. If you choose to include one, it must be after the fuse.

If you really want to go with just ONE transformer, it is possible to generate multiple voltage outputs using switching regulators; however that is a somewhat advanced topic.
 

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