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Help required on Logitech Z-2300 toroidal transformer #2

cero10

Oct 12, 2020
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Hello guys. I want to power the z2300 with dc power but the 2x26.4V I have to feed the system after the rectifier is quite perplexing to me. Can someone tell me how can one or two DC adapter(s) handle this situation?

Moderators note : This post is moved from an old thread:
Help required on Logitech Z-2300 toroidal transformer
 
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cero10

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Can you be more specific, please? What is perplexing you?
First of all thanks for moving my reply. Is it possible to have a single Li-Ion battery pack act as a dual dc source in this manner?
1. 2.png

or two separate Li-Ion battery packs:
2. 1.png
 
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Bluejets

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Where does the transformer come in...??
Transformers work on ac, not dc.

I suspect you are talking about converters, not transformers so show your complete diagram.
 

Harald Kapp

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If the single pack has a center tap, #1 would work. However, afaik cell packs are not meant to be used in this configuration. Therefore #2 is imho the better option.
 

cero10

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Where does the transformer come in...??
Transformers work on ac, not dc.

I suspect you are talking about converters, not transformers so show your complete diagram.
Normally z2300 is supplied ac power from a dual transformer to a rectifier which then gives out +26.4V -26.4V and its keeping the ground from the transformer. I am just skipping the ac to dc part and I want to feed the z2300 dc power.


If the single pack has a center tap, #1 would work. However, afaik cell packs are not meant to be used in this configuration. Therefore #2 is imho the better option.
I was kind of expecting that...so in order to avoid any explosions I will go with #2. Thank you Harald for your advice.
 
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Bluejets

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Normally z2300 is supplied ac power from a dual transformer to a rectifier which then gives out +26.4V -26.4V and its keeping the ground from the transformer. I am just skipping the ac to dc part and I want to feed the z2300 dc power.

As quoted earlier, I think you need to supply the complete diagram.
As it stands, if your original unit was a split supply, your #2 diagram will feed reverse polarity voltage to the normally split negative supply.

Shown attached is a standard arrangement from a transformer rectifier.
 

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Harald Kapp

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your #2 diagram will feed reverse polarity voltage to the normally split negative supply.
Right, I overlooked that detail. The batteries need to be placed as in the first diagram.
 

cero10

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As quoted earlier, I think you need to supply the complete diagram.
As it stands, if your original unit was a split supply, your #2 diagram will feed reverse polarity voltage to the normally split negative supply.

Shown attached is a standard arrangement from a transformer rectifier.
The z2300's original setup goes like this:
ac.png

So from what I understand my two battery pack arrangement would be like this:
dc two bat pack.png
 
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Bluejets

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Where you are getting yourself all confused is the reference point for the voltage measurements which is normally ground.

Your photo 1 above shows as correct and although the photo 2 is exactly the same arrangement , you show voltages with reference to the negative supply.
It should be the same as photo 1.
Just watch your colour coding as it will end up with your having the lower converter getting connected a-about.
 

cero10

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So is this the right way to illustrate it?
dc two bat pack.png

The rest of the connections are correct right?
 

Bluejets

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Yes correct, although I would tend to use conventional colour coding for positive (at least part of) in the lower leg.
Others may disagree.
 

Harald Kapp

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Two step-up converters will usually not work as you expect. In a step-up converter "-" in = "-" out thereby creating a short circuit for the lower converter:
upload_2020-10-17_15-52-30.png
 

bertus

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Hello,

I would disconnect the two battery packs:

dc two bat pack separated.png

When the step up converters are not isolated you would get into trouble with your setup, as @Harald Kapp explained.

Bertus
 

cero10

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Hello,

I would disconnect the two battery packs:

View attachment 49506

When the step up converters are not isolated you would get into trouble with your setup, as @Harald Kapp explained.

Bertus

I don't exactly understand how this works but if there no other detail overlooked, i guess I got my answer. thank you all guys.
This is how it looks dc two bat pack.png
 
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