Need more power for my project, what to do?

hi all,

So, months long project is almost done but now i have a problem with powering it.

So, i am using one UNO and one MEGA board. Uno has just 6 LEDs connected to it but MEGA has 12 7 segment displays that i run on full brightness pretty much most of the time. Most of 7 segment displays show 5-6 digits so they draw a lot of juice. Also, i still need to add like 20 LEDs to MEGA....

I am currently using cheap LM2596 power supply

This works but i would not rely on it to work safely forever, it does get hot and i was even thinking of installing a small Noctua fan 40x40mm, i did a test and it did a great job but again, i would then have a cooler running all the time...

Another idea came to my mind, to connect TWO of these power supplies on a vero board, connect their grounds together and then make a separate VCC lines. Then i could power arduino boards from one, perhaps even a few displays and remaining displays on the other. This way they should run cooler i think. Is this a good idea?

Are there any more powerful PSU's?

Any other ideas?

Any help would be highly appreciated!

Many thanks,
Alek

You can use as many separate power supplies as you like, as long as you connect all the grounds.

Or use one that can supply more current than will ever be required (and use wiring to match the current). There are thousands of different types, shapes and sizes of power supplies.

Thanks jremington!

Yes, the best option would be to use higher rated PSU but i am not really aware of any ready made solution… i think my current draw is somewhere around 1.5A and while this cheap PSU is rated at 2A i doubt thats correct, so i would go for 3+A to be safe. Any ready made solutions i could try?

oh and one more thing, i am using wall wart 9V 2A currently, i will get one with 3A or more but i was wondering, does it matter what the input voltage is in terms of heating problem? Will it heat more or less with 12V input? or the same?

Many thanks,
Alek

The higher input voltage to the 5 volt converter the higher heat discipation.
Why not combine the wall wart and 5 volt generation into one unit? I suggest a 5 Amp rated device.

Thanks Railroader!

Why not combine the wall wart and 5 volt generation into one unit?

As i not schooled for electronics, how do i do this? :slight_smile:

5A? really? i was not aware i would need that much

Many thanks,
Alek

Any ready made solutions i could try?

I used (for example) "buy 5V 3A power supply" as a Google search phrase and got over 11 million hits.

Well, if Your current consumtion really is 1.5 Amp a 3 Amp device would do. I just wonder how accurate Your estimation is. The difference in price and size between classes that close is small.
How well have You been calculating that current?

I used (for example) "buy 5V 3A power supply" as a Google search phrase and got over 11 million hits.

Yes, thats the first thing i did, and not only that! I ended up buying a dozen of those just to discover that they produce way too much noise and the sketch running on UNO board really does not like it (DCF77 signal decoding and filtering) This cheap one is the only one i have no noise with, at all!

Well, if Your current consumption really is 1.5 Amp a 3 Amp device would do. I just wonder how accurate Your estimation is. The difference in price and size between classes that close is small.
How well have You been calculating that current?

I have used my desk power supply unit and it shows a draw of cca 1.5 A (it was actually cca1250mA) but since then i added a few more displays.

Most of cheap wall wart PSUs are not well regulated so i need one that produces least noise, money is not a question here but i just dont know what to look for...

Many thanks,
Alek

You can add external "noise filters" to any power supply, or to your project board. Supply the details of your particular problem and forum members can help.

Thanks jremington!

Yes, i am aware but that would be opening a whole new chapter for me. I know i can add capacitors and such but i was really looking for a simpler solution, like combining two cheap PSUs i already use and splitting the 5V between devices. Not sure if that would be a reasonable solution or its still better to start making a new power supply, especially considering that i was trying to lower the noise on this project, using this forum and came to a solution of using "LM2596: from my previous post, so just dont want to get into a circle here...

Many thanks,
Alek

If You are satisfied with the device You use then bye a second one and do as You suggested. Split power consumption i 2 blocks.

If You are satisfied with the device You use then bye a second one and do as You suggested. Split power consumption i 2 blocks.

Man i love when people have the same opinion as i do, even if it's sort of forced or guided hahaha, sorry, i had to!

Yes, i am very satisfied with this one, my only concern was it is cheap and perhaps under powered, so i was asking for confirmation that i can combine two and split outputs so neither one is under heavy load.

I would feed both with the same input power? no need to add anything extra?

many thanks,
Alek

Make sure to connect the Gnds together, and to the Arduino, so all have common reference.

That wall wart is not enough, only 1.5 - 2 Amps. I would buy a second one, or a stronger one!

Make sure to connect the Gnds together, and to the Arduino, so all have common reference.

Yep, on it! Thanks!

That wall wart is not enough, only 1.5 - 2 Amps. I would buy a second one, or a stronger one!

Yes, i am looking for one with 3+A.

Should i stick with 9V, worked nice so far...

Thanks,
Alek

Yes. 9 volt has been okey so faar. What does the specifications of the converter say about minimum input voltage?

it says: "The LM2596S voltage regulator is ideal for reducing voltages to a required level. Due to the wide input voltage of 4.5 - 35V, this module can be used in many ways, e.g. to regulate the voltage between the Arduino (5V) and a sensor (3V)."

Should i try with 5V wall wart? Would it still output 5V and perhaps reduce heating?

I should connect and check with my multimeter...

Many thanks,
Alek

I read that the LM2596S reduces to a certain voltage. That tells me that You need "some more". How much more? That info must exist in the specifications.
To produce 3.3 volt maye an input of 5 is ok..... For 5 volt You surely need more than 5. Find out how much or continue using the 9 volt wall wart.

thats what i think, 9V works nice so i think i will stay at 9, just bump up the Ampers.

Many thanks again for all your help and tips!
Alek

My pleasure.