Other option to consider - read datasheet of the chip: http://www.ti.com/lit/ds/symlink/lm2596.pdf, read "typical applications" chapter. There's circuit for 5V regulator with all the components specified and layout examples. Just copy it and you are done.
This is gold. Thank you!
Why struggle designing your supplies if there's so many easy solutions around. Better invest your time into something else that's really worth your time.
What do you mean by struggling to design my own supplies? I haven't found an easy solution to my problem yet. I want a single PSU that plugs into the 240V AC mains, converts that to 12V or 20V DC at the other side, and then to split that into a sufficient number of 5V DC conductors to power SBCs, each of which draws a peak of 0.5A.
If I treat the "LM2596 Fixed Output Series Buck Regulator" (Section 9.2.1, Figure 32, in the PDF data sheet you linked me to) as a
black box whose output is going to be wired to a connector of the appropriate size, then could I put several of them in parallel? I intend to split the 12V or 20V DC PSU output and multiplex that across the inputs of these black boxes, provided that there's enough power.
If you know of an easier, ready made solution for my problem, I'd love to hear it because buying something like this off the shelf would save me a lot of time because there are so many other things I need to work on.
To feed 5V DC-DC converters 12V is optimum "popular" voltage.
Really? I have one of these, which is genuine:
Brand: EDACPOWER
Model: EA10681U-120
AC in: 100-240V 2A 50-60 Hz
DC out: 12V 6A
Somebody else told me that the 12V 6A DC output is strange and I would need very thick conductors to handle that sort of current. They said a 20V output (which would then have half the current), would be preferable because the voltage drop would be less, and less energy would be wasted by turning into heat, etc. What do you think?
Get some 12V LED constant voltage supply and you are done.
I don't know what this is. Can you point me to an example please?
Obviously any other powerful enough 12V DC supply you can find in your junk box will be good, including some old laptop supply. Do not pick higher voltage than 20..24V.
I don't have much of a junk box because I have only just recently regained my interest in electronics, and we got rid of all our old e-waste because we move around a lot, have recently started a family and were focused on having clean(er) house (that's a discussion for another thread). At the time I didn't foresee a use for all these old laptop charging bricks and similar such things.
Actually ATX supply have 5V output you are looking for. Only modification would be simple jumper wire in the ATX power connector to power it on. Thou most likely it is too big and too powerful for you, does not have enclosure as well.
Indeed. The ATX PSU would be IDEAL. I even have a spare, nice one that I'm not even using at the moment:
https://www.bequiet.com/en/powersupply/935 But it has no enclosure, we have two curious cats and an 18-month daughter who loves to look at what I'm working on and poke around and press thing, and it's a high-power device. I don't know how safe it would be to work with this, or maybe I'm just being paranoid.
The extra nice thing about an ATX PSU is that it also has a 3.3V output, which I'm also going to need to power SPI flash chips that I'll be repogramming (this is one of my applications of working with PSUs and SBCs). In other words, I'm working with SBCs for two reasons:
- To use them to flash new BIOSes onto flash chips of old computers that I'm experimenting with. This will be done by running the flashing software on the SBC, wiring a SOIC-8 or SOIC-16 clip to the SBC's GPIO, and running the appopriate flashing software.
- I am building a cluster of SBCs because I want to learn about clustering, about the SBC's architecture, and about ARM.
BTW, the SBC I am referring to is the Orange Pi.
Can you please recommend a basic book about electronics that specifically covers power supply fundamentals?
No need to become expert in power supplies. Manufacturers already assembled ready to use designs with extensive comments. You shall read datasheets and application notes of the ICs, copy reference designs. Usually this is enough to get your supply running. Apart from just buying ready to use modules..
A big reason for this is education. Indeed, I would prefer to purchase as much of this off the shelf as possible, as my main goal is to get these SBCs running, start flashing some BIOSes, and build that cluster I mentioned earlier. The PSU issue is a bit of a distraction, but an interesting one, and I want to keep it going on in the background over time as I am missing an understanding of power electronics, which would be useful for many other things too.
I have a copy Horowitz and Hill, though. Is there anything else "classic" like that? I need something for when I get stuck on basic concepts! I want something that the basics in very nice way, or is an enjoyably readable, standard reference (like H&H).