# Looking for simple explanation for simple RGB led strip problem

#### Finnekusu

Joined Jun 13, 2020
2
Hey all
Currently looking for some advice and help for a simple problem.
I have build that includes a RGB led strip and amplifier with 2 speakers attached.
I would like to use a splitter to power both from one wall socket.
Is there a way to calculate the amperage needed.
Alternatively
can I get a adapter that is overkill say 8-10 amps or would that overload the strip and speaker

Last edited by a moderator:

Joined Feb 20, 2016
3,781
A power supply of higher current is no problem at all. As long as the voltage is ok, the loads will only take the current they need.
For instance, a car battery is capable of 100s amps to start the car, but the clock running off the same battery only draws a fraction of an amp.

#### MisterBill2

Joined Jan 23, 2018
8,213
There is no mention of the voltages required. Certainly something can be done but without knowing the voltages no useful halp can be offered.

#### ci139

Joined Jul 11, 2016
1,696
the € wall usually outputs 240V.rms · (5.999A / (1+10% · 1.5)) ≈ 1.25kW (max. input from the wall)

the SMPS flybacks usually . . . might have efficiency around 86%

so IF your devices use less than 1kW (max. output to the devices . . . is what your amp and LED-s require . . . both together at their max.)
. . . THEN you likely can put 2 SMPS to the same wall outlet (. . . in Europe !!!)

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#### MisterBill2

Joined Jan 23, 2018
8,213
A reasonable power supply certainly can replace the two power supplies presently being used. BUT the TS will need to read the labels on those supplies and let the rest of us know both the OUTPUT voltage and the rated output current from each of them. This may require adequate lighting and possibly a magnifier. When we know that information, providing a useful and correct answer will be possible.
Otherwise the TS will only get useless answers, as in post #4. Really, that answer does not help at all.

#### Tonyr1084

Joined Sep 24, 2015
5,804
Welcome @Finnekusu to AAC. All you need to do is give us a little more information and we can likely give you a good answer. Otherwise, the best anyone can genuinely say is that if your supply has the correct voltage and sufficient current capability - you should be able to power both from the same supply.

IF (and here we go with conjecture) your amp runs on one voltage and your LED strip runs on something else then the answer becomes more complicated. Still, AAC members can in all likelihood give you the answer you need. Even if that answer is "No, what you want to do can't be done the way you propose."

Again, welcome to AAC.

Joined Jan 15, 2015
5,875
Alternatively
can I get a adapter that is overkill say 8-10 amps or would that overload the strip and speaker
In a word yes but before I really say yes it would be nice to know the actual loads. Long as the adapter can support the loads then no problem.

Ron

#### ci139

Joined Jul 11, 2016
1,696
the power amp likely likes an "overkill" supply --e.g.-- the one with low internal resistance
. . . but such does not necessarily mean it has to be able to output much amps over the demand of the amplifier

#### MisterBill2

Joined Jan 23, 2018
8,213
Once again, before it is possible to provide any useful advice we need to know the voltages provided by the present two power supplies, and the current rating from the labels on those power supplies. If those are not available, then possibly some more description from the thread originator of the two items being powered. Otherwise all of the advice will be guesses, at best.

#### Finnekusu

Joined Jun 13, 2020
2
Hey thank you for the help so far. I apologize for the slow reply. Joy of being a "key worker" and doing a 60 hr week.

So the amplifier is 12v 2A and the RGB led strip controller is 12v 6A(max).

#### Tonyr1084

Joined Sep 24, 2015
5,804
the amplifier is 12v 2A and the RGB led strip controller is 12v 6A(max).
OK. Much needed information.

Sounds like you're describing the power supplies. Both are 12 volts. One has a max output of six amps, the other outputs two amps. Still, we don't fully know what the load will be. But to answer your question directly, a power supply capable of putting out eight amps or more will be perfectly fine for the application you want.

#### MisterBill2

Joined Jan 23, 2018
8,213
If the 12v, 2A and 12v, 6A are the ratings of the power supplies that originally powered the two systems then a totally safe choice would be a 12 volt 8 amp supply.
BUT if the amplifier is not normally operated at full output then it will be fairly safe to simply power the LED load off of the amplifier supply. This should be OK because audio amplifiers very seldom draw their maximum rated current. If the power supplies are not the models originally specified for those two systems then the decision process will be more complicated, and need other information.

#### Tonyr1084

Joined Sep 24, 2015
5,804
Here's what I'm thinking:

#### MisterBill2

Joined Jan 23, 2018
8,213
Here's what I'm thinking:
View attachment 210174
That is what I was describing., except that the power supply could probably be the original 6 amp supply because mostly amplifiers do not run at their max output.
What is ntot totally clear to me is if the two current values are the supply label values or the amplifier and LEDs recommended values. We still ar5e only guessing that those values are what the devices actually draw. More information will allow better recommendations.

#### Tonyr1084

Joined Sep 24, 2015
5,804
That is what I was describing.
I was in the process of drawing this when you were posting. I got the notification that others had posted while I was waiting. Didn't see your post until I was posting.

As far as the amp goes - I've found that an amp CAN hit base notes that can max out an amp. The reason I'd go with 10 amps is to give plenty of head room, should base notes ring back through the amplifier and interfere with the LED's. It may or may not be likely, but as you say, we still don't have the full picture.

I suspect the original PS's are rated for 2 & 6 amps. 8 amps would likely be sufficient. But in the interest of sufficient head room, 10A is my choice. I don't know how easy it would be to find an 8A supply. I suspect (but don't know this for a fact) that a 10A supply is probably more readily available.

At this moment I have an 18V 6A supply. With a buck converter that could be dropped to 12V 9A minus the efficiency of the buck. The supply comes from an old printer. Hewlett Packard printer. It's a brick, same as in the drawing. Other bricks in possession are 12V 5A and 3A. Just have to look around. Also have some old DirecTV receivers. They have built in supplies, and I'm wondering what they rate at. The point is that there are a ton of places one can find a supply.

#### MisterBill2

Joined Jan 23, 2018
8,213
While you and I can probably put our hands on more power supplies than we could carry, that is not the case everywhere. In some parts of the world they are hard to get and expensive. And since the main probl;em with minor overloads is heating, momentary music peaks are usually not a big deal. That is the basis for my suggestion.
Those supplies in the satellite boxes may only have the 12 volts for the communications portion. I have not pulled one of those apart yet.

#### Audioguru again

Joined Oct 21, 2019
2,844
It is easy to determine the maximum supply current for a stereo amplifier with the datasheet of the amplifier IC, the supply voltage and the datasheet for the speakers for their impedance.

#### MisterBill2

Joined Jan 23, 2018
8,213
Many times folks do not get any information at all with purchased items from some on-line sellers. Often used items do not have any information or instructions with them. And a lot of stuff from some sellers has no information at all. Besides that, many amplifiers do ot utilize an IC module as the active device. So at that point it would take a rather serious circuit analysis to determine the power requirements.
And on-line searches often return hundreds of hits claiming to have an item for sale when they have no hint of what the item even is..