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It's most likely a Switched Mode Power Supply (SMPS). I'm not saying it couldnt be a linear regulator without seeing it,but at that power level 720W its likely an SMPS.

You might want to try something less ambtious if this is your first foray into SMPS's . They can be difficult at 7W let alone 700W.

A good basic IC to use; to learn some basics about variable linear regulators is the old LM723. You will soon see the problems and expense of building a linear regulator at 12V/60A.

A good basic SMPS CONTROLLER to use is the NCP3063 which is an upgraded version of the old MC34063A-D.

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LM723

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Googling anyone of those part numbers will get you a wealth of info.

Everything you could want to know about SMPS well almost; nothing beats frying a few controllers and what not on the bench;-)

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basic simulator

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Small steps first grasshopper;-)

Reply to
Hammy
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I should've added this. Browsing manufacturers sites can get a lot of your questions answered. For instance

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What you want is

Linear & Switching Voltage Regulator Handbook

and

SWITCHMODE? Power Supply Reference Manual

LT has a free SIMULATOR get it here.

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Reply to
Hammy

Hi,

I am trying to find schematics for PSUs. I found one, probably good one, but it was very complicated and used an IC, which I probably won't get anywhere. So any good links welcome.

I understand the sub 3A PSUs somehow. But for example a 12V/60A ones are mystery to me. One person told me that they use FET's. Are they basically like the PC Power supply? But how they make the controllable between 1.5 -- 12V with full load?

Any schema ?

I hope my continued questions are not regarded as spam...

Best Regards Kari

--
PIC - ARM - DISPLAYS - RELAYS - MODULES - CONVERTERS - I2C - SPI -
KEYPADS - ACCESSORIES
http://www.byvac.com   (I am just a satisfied customer)
Reply to
Kari Laine

UNITRODE has had some nice seminars and books on the subject, as well. TI has taken over and has them on their site.

There are a number of archived seminars here:

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Plus later ones here:

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These seminars also include a number of topics, such as:

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The Unitrode Magnetics Design Handbook, MAG 100A, is at:

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The book itself is labeled SLUP003, but I don't know where to find that exact PDF file. Perhaps someone else can.

Jon

Reply to
Jon Kirwan

Thank you VERY much for all of this information. Would keep me busy some time to come :-)

Best Regards Kari

--
PIC - ARM - DISPLAYS - RELAYS - MODULES - CONVERTERS - I2C - SPI -
KEYPADS - ACCESSORIES
http://www.byvac.com   (I am just a satisfied customer)
Reply to
Kari Laine

Kari:

I would recommend starting out with a linear supply, unless you have a specific project that needs more amps. Unless you are already into power electronics (motor controllers, etc), I think you will find that 1 amp supplies will be just fine for almost everything else. 1 amp will be more than enough for projects with multiple op-amps, for example, and/or lots of CMOS chips.

The way it has always worked out for me, is that projects that need more power also need their own supplies anyway, such as audio power amps.

I'd suggest starting with +/-15V supplies, which you can use for most op-amps, and for a lot of CMOS digital stuff on just the 0-15 supply. You may also want a 5V supply for low-voltage op-amps and logic.

These can all be built with readily available

1-amp linear regulator chips, and they are super simple. I would stay away from SMPS designs until you have a definite need for more amps. Not only are they mode complex, but they involve high frequencies that can really mess up whatever project or measurement you are working on.

Plus, if you start out playing with big amps, you can expect some big "phhhttts" along the learning curve. Much better, IMHO, to learn on the tamer stuff... cheaper (and safer) when you make a mistake!

Best regards,

Bob Masta DAQARTA v5.10 Data AcQuisition And Real-Time Analysis

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Scope, Spectrum, Spectrogram, Sound Level Meter Frequency Counter, FREE Signal Generator Pitch Track, Pitch-to-MIDI DaqMusic - FREE MUSIC, Forever! (Some assembly required) Science (and fun!) with your sound card!

Reply to
Bob Masta

Thanks Bob,

yep I will do +/- 12V 1.0A supply. I have already all the parts except housing.

To make housing right seems to be another graft to master.

The "super" switching PSUs. I was more interested to know how they are implemented rather than building one. If I ever need such power I will buy a ready made supply. Reasons are that the currents in that range are so huge that I will surely burn my house with a self made supply.

One question I have though. I am thinking that one cannot use soldering with that kind of currents - can one? If not then how the connections are made?

Anyway thanks to all in this group. This is a great resource.

And about the mains. Before I try to measure it in any way(if there really is need - witch I doubt) I will borrow a book and ask someone how exactly to do that. I don't want to blow up my equipment or kill myself.

Best Regards Kari

--
PIC - ARM - DISPLAYS - RELAYS - MODULES - CONVERTERS - I2C - SPI -
KEYPADS - ACCESSORIES
http://www.byvac.com   (I am just a satisfied customer)
Reply to
Kari Laine

All the switchmode PSUs I've seen are soldered. The important thing at higher currents is to make the copper circuit board traces wide enough. I've never run into problems with this, but it's certainly possible. After all, if you make the trace narrow enough it starts to look a lot like a fuse!

Best regards,

Bob Masta DAQARTA v5.10 Data AcQuisition And Real-Time Analysis

formatting link
Scope, Spectrum, Spectrogram, Sound Level Meter Frequency Counter, FREE Signal Generator Pitch Track, Pitch-to-MIDI DaqMusic - FREE MUSIC, Forever! (Some assembly required) Science (and fun!) with your sound card!

Reply to
Bob Masta

This trace width calculator wil give you an idea. It seems pretty accurate compared a few with a chart of conductor width for current for a given temp rise in my power electronics book.

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But for an SMPS you also have to consider RMS handling for the switching loops.

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Reply to
Hammy

Like bob already said - a basic three terminal regulator is a good place to start. I would find a variable supply more useful, if I just had one. Plus and Minus supplies find most of the applications in linear electronics - and from you sig file, I get the idea that perhaps you are more interested in digital (learning to run before walking?)

I keep one small variable three terminal supply, two independent 12 VDC fixed supplies (separate cases and line cords), and one 12-24 unregulated heathen (lot of amps with circuit breakers), and a variable (variac controlled) 0-18 / 5 amp with circuit breakers, and one I call my "come along" brute force ~15 Volts with no protection and enough output to start an outboard motor , and motorcycle (maybe a small car too).

My tinkering is mostly with the variable 1 amp supply (a volt meter mounted to it would be nice - read: "damn near necessary" yet I never get around to it). The "picaxe" is mostly with 2-3 AA batteries (only needs some micro amps), or a 5V regulated supply for the axe, and an X voltage for the peripherals (mostly for the convenience of having one switch control everything)

Check out the picaxe. Really amazing fun device. Low cost. No programmer required. Free software. Just an RS232 serial port on your computer, and three resistors to program, using BASIC, and maybe a breadboard with three AA cells on it. Total outlay

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