Please recommend a high power 5v switched mode regulator - Page 1
Forum section: electronics / projects

author: andywhy
author_rank: Newbie
timestamp: May 06, 2013, 06:12:03 pm
content: Hi all,I'm to the forum but I've been a fan of the EEVBlog videos for a long time. I hope some of you can help me out!A bit of background info:Last year I built a "portable power box" for camping, see my project blog post here:http://www.andrewwhyman.com/blog/electronics/portable-power-box/.It involves a 90Ah 12v SLA battery, 4xUSB 1A sockets, 2x5A cig sockets and an LED bar graph voltmeter. A very basic project in many respects but it, for me, involved a lot of research. It was my first project on this scale and it ended up being incredibly messy, so I decided it might be time I re-did the project using knowledge gained since then.My first hurdle is the 5v regulators. I originally considered LM7805's, but they ran far too hot when above 400mA draw on 12v even when heatsinked. I then found the LM2575T-5 which is a 5v 1A switched mode regulator. This ended up going into the final project. I had 4 of these each running their own USB socket and used a resistor setup on the data pins to make the phones charge at the full rate.My query is this:Can anyone recommend a similar switched mode regulator to the LM2575T-5 which will run up to 2A of current? I have had trouble finding any that are within a decent price range. I can get a single LM2575T-5 for about £1.50 GBP, which is reasonable. Others I've found run in ther £5 GBP or more region which is insane.I assume these will also need an accompanying inductor as well. Which value would you recommend? I have 200uH 1A rated inductors but obviously they're unlikely to be suitable unless I can parallel/series them in a configuration that will work.Sorry for the long first post, but I wanted you to understand what this was for before you recommended anything. I'll have more questions at a later date.Thanks,Andy

author: Flávio V
author_rank: Regular Contributor
timestamp: May 06, 2013, 08:38:46 pm
content: There is the lm2576(37V 3A 50khz) than is around 2-3€...

author: andywhy
author_rank: Newbie
timestamp: May 06, 2013, 09:45:31 pm
content: Thank you very much. I didn't even realise there was a model up from what I was using!

author: free_electron
author_rank: Super Contributor
timestamp: May 06, 2013, 09:50:16 pm
content: lm2595 should do 5 ampere i believe.

author: Balaur
author_rank: Unknown
timestamp: May 06, 2013, 10:02:51 pm
content: I can vouch forthis oneEDIT: I have the 5A version, not the 10A shown in the link. Strange, the 5A one is nowhere to be found.I don't know how the regulator will behave in time, but the initial behavior and performances are rather nice:(please note the x and y axis)

author: madires
author_rank: Super Contributor
timestamp: May 06, 2013, 10:07:43 pm
content: Quote from: Flávio V on May 06, 2013, 08:38:46 pmThe 5V fixed voltage version in TO-220-5 is 1.15€.

author: mikes
author_rank: Regular Contributor
timestamp: May 06, 2013, 10:29:05 pm
content: You can get LM2596 based boards (ready to go, adjustable) from China on eBay for <$2 each in qty 5. That's cheaper than you can get just the IC from Mouser or Digikey (in the US). They say 3A, but I only trust them for 2A continuous. They'll be much more efficient than a linear regulator.

author: andywhy
author_rank: Newbie
timestamp: May 06, 2013, 11:06:49 pm
content: Thanks all. I actually plan on building my own board with these PSUs on it along with an Arduino and an LCD for various bits of monitoring. At the moment it's split horribly between 3 boards with wires everywhere.I've found the regs at £5 for 10 and the toroidal inductors at £8 for 10. That should get me going and is reasonable on price.