Making a power supply.

Hi.
I have an amplifier. It needs a 12v-0-12v transformer.
I have two 12v adapters.
Can i attach these two adapters like this(shown in image) to get 12v-0-12v???

Picture of Making a power supply.

If you are trying to do what I think you are trying to do, the picture you have drawn is wrong. The wire you call "0 V" should be connected to a negative wire from one adapter, and a positive wire from the other adapter. I mean take the picture you drew, and switch the output wires from one of those adapters, and that will look better.

When you stack voltage sources on top of each other, it is always plus to minus, the same way as is done with battery cells.

I mention this because this is probably something you have seen before. You know, you've seen a toy, or something, that takes 4 AA batteries, and they are all wired in series, with the positive (+) terminal from one, connected to the negative terminal (-) of the next to give 4*1.5V = 6.0 volts, across the whole stack.

AC adapters can often, but not always, be stacked in series, in the same manner as battery cells, for to give more voltage, or to give more than two voltage rails.

The quality that determines if this is possible, or not, is whether or not the the AC adapter is isolated,

https://en.wikipedia.org/wiki/Galvanic_isolation

from the mains power. And almost always, AC adapters are made this way, so there is no actual conductive path connecting the output rails, on the DC side, to the AC mains rails, named "hot" and "neutral".

One thing to watch out for is some AC adapters, particularly those with a plug with a "ground" conductor, sometimes they will connect the negative terminal of the DC side to the ground wire of the mains supply. For example, for the ubiquitous desktop computer power supply (eg. ATX), the ground (=0 volts) is connected to the metal case, and also the ground wire of the mains supply.

To stack two desktop PSUs in series, it is necessary to
disconnect the wire that connects to the ground of the wall plug, and
also make sure the two metal cases to do touch each other.

Also, I am naively assuming you want three output rails, with voltages, {+12 V, 0 V, -12 V}

When you write "12v-0v-12v", it is confusing because I cannot tell if "-" is a word separator, like a space or a comma, or if "-" is a math symbol meaning "minus". I am guessing you want, {+12 V, 0 V, -12 V}, because you said it was for an amplifier, and often, but not always, amplifiers want a supply like that.

To be clear, when you put your voltmeter's probes between the +12 V rail and the -12 V rail, the voltmeter will read the algebraic difference between these two numbers, i.e. Vdiff = +12 V - (-12 V) = 12 V + 12 V = 24 V.


Shezi007 (author) 24 days ago

Hi.
I have an amplifier. It needs a 12v-0-12v transformer.
I have two 12v adapters.
Can i attach these two adapters like this(shown in image) to get 12v-0-12v???

12V.JPG
Shezi007 (author) 24 days ago
Sorry, i just forgot to upload IMG.
Here it is.
12V.JPG