How to convert a computer PSU to power LEDs?

Question

Do it yourself

Hello everybody! I must say right away that I am not an electrical engineer, but a programmer, so make an allowance for incompetence.
My task is to take the power supply from the computer and power the controller for several led strips. There can be several tapes, voltage 5V, power of one - 15-40W.
A few questions came up:
1. If I just take a 5V line and connect it to the controller, will the PSU work normally? It is clear that I will take into account the maximum power and not overload. I heard that the PSU does not feel very good if you load only one channel.
2. Plus, I want to be able to connect the battery with 12V later, how can I do this? Maybe it is possible to power the PSU from 12V and then get 5V in the same way as in the previous version? That would be the best. Or is it just a step down converter 12-5? If the second option - then tell me how to do it better?
3. If in the second question it will be necessary to install a step-down converter - then can then take 12V from the PSU immediately and let it through it?

Thank you all in advance for your replies!

Answer 1

address tape

Apparently, what you called an address tape would be more accurately called a matrix, since it is easiest to organize individual control of diodes by connecting them to nodes of rows and columns. It became clear why 5 volts.

If I just take a 5V line and connect it to the controller, will the PSU work normally? .... I heard that the PSU does not feel very good if you load only one channel.

In my opinion, you can use the 5-volt channel by itself, without regard to the others. Voltage stability will be maintained, despite the underloading of the remaining channels, since the computer PSU provides special measures for such cases - the so-called. group stabilization circuits that help maintain the ratio of output voltages under uneven load. If you are allowed to have output voltage deviations of up to 10 ... 15%, then you can not rework the PSU.

I want to then be able to connect the battery with 12V, how should I do it?

If so, then this crosses out what I wrote above, or at least forces you to use a 12-volt output channel instead of a 5-volt one.

Maybe it is possible to power the PSU from 12V and then get 5V in the same way as in the previous version?

Enthusiasts have tried this upgrade of standard PC PSUs, but you'd better not look in that direction, since such a conversion is quite difficult. It is better to introduce battery power purely from the low-voltage side - it will cost you only a couple of Schottky decoupling diodes.

Or is it just a step down converter 12-5?

Exactly. The Chinese sell a lot of suitable buck converters, some of them are quite economical, with high efficiency (I'm hinting that they will not require additional fans). The 5-volt channel of the PSU itself cannot be used, unfortunately. This is the inevitable cost of battery power.

If in the second question it will be necessary to put a step-down converter - then can then take 12V from the PSU immediately and let it through it?

This is the option I'm talking about.
As for the fan and the noise from it... Its removal is the most inconvenient alteration of a computer PSU. We can discuss it too.

Answer 2

Take the power supply and power the tapes from any line that matches the voltage.
1. Will work fine.
But in any case, this is a collective farm - to have a huge box with a noisy fan instead of a cheap compact switching power supply.
On ali, unpackaged ones cost 123 rubles.
2. It is possible through a 12V-220V converter, but this is an even larger collective farm.
Find a converter that takes 12V at the input and outputs 5 at the output.
On ali - 90 rubles.

Answer 3

Reading the question carefully. I strongly recommend buying a special power supply for LEDs.
Without going into technical details, the LED needs to stabilize the CURRENT and NOT the voltage.
Of course, you can connect to a computer PSU, but without special knowledge, this process will NOT be rationally long and NOT guaranteed to be successful.