Pairing Power Supplies

[Mtn Lynx]

Is it possible to pair two switching power supplies? Example, two 30 amp power supplies to make 60? Or would it still be 30 amps even if there are two. Just wondering because I'm considering a box that requires more juice and I don't want to buy a $400 supply.

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[sonoma]

it would be 60

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[295 antenna]

yes it is but they have to be made to do that. A company called (mega watt) has just that set up.

also i found this article.. https://electronics.stackexch ... rent-outpu

[MDYoungblood]

yes it is but they have to be made to do that. A company called (mega watt) has just that set up.

also i found this article.. https://electronics.stackexch ... rent-outpu

Check the sponsor's list, they are one of the site sponsor's, also the owner is a member here, "12voltpower", you can PM him from his member page.

3's

Greg

[295 antenna]

Cool MD i didnt know about his CBRT handle...

[Mtn Lynx]

Thanks, appreciate the replies.

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[Scipio Kid]

Hey Mtn Lynx, How's the weather in Alaska? Getting warm? Got the midnight sun going?

I know they say you should have matched power units to pair them up but I have to disagree, from experience. I've done a bunch of piggy back power supplies for all kinds of applications and never had a problem. It's just like dual batteries in a truck. same voltage, double the amperage. (Well unless you go in series and then you get twice the voltage and the same amperage, but you'd need an old military jeep for that!) I understand varying manufacturers will have slightly varying output voltages and I think this is where and why some say you need to match them. In my experience, it simply doesn't matter, if one is putting out 14.5 volts and the other 12.8, they'll just average out at 13.6 when you hook em' up parallel. Now, of course, if one is damaged, bad diodes or something and putting out A/C then there will be trouble matched or not. The same holds true with A/C transformers. So long as the output voltage is similar, (and you properly phase the output leads) you'll never have any trouble. I've used piggyback transformers to run huge multi-valve zones on golf courses and cemeteries when we installed bigger pumps to double or triple water output. Saves thousands of dollars in new control costs. I even ran one 50 acre cemetery on a little Rainbird 6 station clock (with a big transformer piggybacked on the tiny one in the time clock). I've doubled up Micronta and Pyramid supplies many times, no trouble at all. I think you're good to try it with what you have so long as you know both supplies are in good shape. They don't need to be the same size either. If you have a 40 watt and a 15, you'll still be able to draw 55 watts without any trouble. (However, if you do this and everything blows up, and you burn down half of Alaska ... you never heard of me, OK?)

[Mtn Lynx]

Weather been cloudy past couple days. Cold outside, been out commercial salmon fishing for keta. Just got back this morning, got another 1k #. I have a 30 amp power supply. Might get another of the same to power a bigger box. Been hearing some big boys on 6 am. They can't hear me, some are loud, had switchblade, baby boy, preacher man rocking my radio last week. Can't get a reply.

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[sonoma]

some of those guy's on channel 6 run 3 to 5,000 watts. a few even more. so good luck with that one. a few of them here are about 50 miles north of me and they over drive my radio and have to turn the rf gain down to get them to the point I can understand them. most run a large beam also.

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[Scipio Kid]

Hi, me again,
I hand't read the article 295 antenna linked to when I posted my rant. Clearly, there is validity in the article but it deals more with technical theory than practical application. However, I suppose if the initial voltage discrepancy between the two PS's was high enough and the voltage regulation stringent enough to keep the higher of the two at that high ratio no matter the induced load, well then I'd have to agree, the one would handle the bulk of the load. I've just never seen a PS so precisely regulated, particularly the garden variety types we're all used to. (With A/C, there would almost never be a regulator in the first place.) But when you're using typical PS's, designed for a 12V DC load, you'll typically find they put out 13.4 V at no load and drop to about 12.5 at peak load. If a secondary P.S. is added, you will simply see the composite curve slowed with a similar load and mirrored with the load doubled.

So Mtn Lynx, check both your PS's output voltage unloaded and loaded (but separate ... use the same load for accuracy). Unless one is consistently lower than the other I'd say by at least 2 volts, then I wouldn't worry about it. To be sure (and to avoid that "half burned Alaska" thing I mentioned) I'd pair your PS's and then, while under load, check the current draw (not the voltage) on each of them. If it's similar, (split 50/50) you'll have no problem whatsoever. If, as the article states, the current is high on the one and negligible on the other, well then, you have a problem.

If you do find you have a problem, let us know and I'll shut up. I'm good at that. NOT

5000+ watts! That's nuts. how do they pay their power bill. When you're pushin' that kind of power, you'd better be making bank on it or what's the point? Just bragging rights to say you're walking all over everyone else? Like I said, nuts.

I haven't heard a thing the past few days. No skip anywhere on any channel here. No wait, I did a service project Saturday with a bunch of youth and as they piled into my truck, to go home, one asked what the radio was. I turned it on (not sure what channel, may have been 19 for the road or 22) and had what sounded like all kinds of skip. Now I was only a mile from I-15 so it could have been road noise but it sounded like heavy skip. Some idiot started cussing up a storm so I shut it off. I meant to tune in when I got home but, after a hard day's work, I crashed instead. I'm good at that. But that's the only thing I've picked up in almost a week. Right now, nothing but static. I can't even hear the big trucks at Kennecott. Dang, maybe my antennas are down!

[Mtn Lynx]

It's been cloudy and intermittent rain for a few days, radio has been dead quiet. Got 2k # of keta yesterday. Prolly going to try one of those mega watt 295 and MD was talking about. Still trying to find the right box tho.

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[Scipio Kid]

When you do, give a shout out to Utah. You said you were talking to Montana the other day. When the skip is good I can always get into central Canada. One of these days, I'm sure we'll hear each other.

So, 2 thousand pounds of Salmon? You know, when we go fishin' here in Utah, on one of the many high mountain lakes or streams, we're always happy to come home with 3 or 4 nice 12" rainbows. That's probably smaller than the bait you guys use in Alaska. Thanks for rubbin' it in.

[jon6667]

i have 2 megawatt ps tied together. for 60 amps at 14 volts
they work great

[Pioneer621]

A pair of switching supplies should parallel just fine. Best not to push them to max current, but you generally never do that to a power supply.

I've paralleled many supplies over the years when I needed some extra current. From cheap pair of 2.5A Micronta linear supplies, to mis-matched switching supplies; meaning one 40A unit running with a 45A unit with no issues. This allowed me to run items the individual supplies couldn't handle, but together got the job done, I've done this many times when some extra current was needed. I would of course suggest sticking to a matching pair of supplies if you do this. I've been playing with this stuff for many years, so have no problem experimenting and always prepared to let the smoke out of things should I be wrong when testing.

A pair of matching switchers I wouldn't worry at all, and if you can set the voltages closely, all should be well.

The dirt cheap "server" power supplies may be an option, decent current and easy paralleling, some you can tweak the voltage slightly as well.

[MDYoungblood]

I've never tried to pair power supply's but was always told they have to be identical, there is some diodes involved in pairing them also. I'm sure if you PM "12voltpower", he will set this topic straight.

3's

Greg

[Crusher]

The diodes are so the power supplies don't actually see each other. Otherwise if not dialed in right, the will fight each other.

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[Mtn Lynx]

Haven't gotten around to getting the PS. Should be in couple weeks. Dang, should have got one when they were cheaper mid winter.

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[12voltpower]

The diodes are so the power supplies don't actually see each other. Otherwise if not dialed in right, the will fight each other.

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Our two smaller units like diode isolation to fool the over currant limiter. It is possible to connect two in parallel if you set the voltage identical and monitor the heat on the left side of the case (location on the duel schottky rectifiers). Make the heat the same buy adjusting the voltage in tiny amounts. Its risky but it can work. A car battery diode isolator works great for cheap diode isolation. The S-700-12 50 amp is made to parallel as many as you want.