SMPS Greenhorn

[firethorn]

Hi there. I'm wondering if someone can push me in the right direction for learning more about SMPSes.

I've built a guitar power supply with a lot of power but it's very bulky as it's linear. I seriously need to cut down on the real estate.

It's been a very long time since my last bit of progress on this issue.

So far, the only keyword I've managed to get is SG3525. The other obvious keywords always lead me to smps.us. I assume it's a great site but I can't learn much off it. I am now quite familiar with the second half of an smps circuit but I am still very unsure about the first.

What I know about SMPSes is still very fragmented. If possible, it would be great to see a simplified but not pseudo-fied schematic. What are the common designs and chips for regulation and etc...

I am not sure if the Internet has failed me or if I just aren't typing the right things to look for.

My understanding of an SMPS is that it's directly (sort of) tied to mains. This is not something I want to try with trial and error where possible.

I've even considered giving up in this area all together and just buying one of those premade open-chassis circuits.

Any help would be greatly appreciated.

Cheers,
firethorn.

[pacificblue]

http://en.wikipedia.org/wiki/Switched-mode_power_supply explains the basics.

At the bottom there are links, references and a book list for deeper investigation.

[star882]

What voltages at what currents do you need? There might be a cheap supply out there that will work as-is or with a little modification.

While building a line powered supply is certainly not recommended for a beginner, low voltage switchers are very good for learning how switching supplies work. My first switcher accepted an input of about 25v (rectified 18v) and outputted 1.25-20v at 1A.

[firethorn]

Planned to take in 110-240VAC to 15vdc.

will see if those links at the btm of wiki turn up anything... funny.. i missed that.. lol

[marce]

http://www.national.com/appinfo/power/files/f5.pdf

http://www.national.com/appinfo/powe...esigner114.pdf

http://www.national.com/appinfo/powe...esigner120.pdf

Above is a small selections af Nationals stuff. There is aslo stuff at other manufacturers sites. Find some switching regulators by different manufacturers then you find application naote etc etc.
Have Fun

[Electrone]

National Semiconductor is good for a beginner because it covers already isolated stuff like will operate off a 60Hz transformer PSU or a purchased SMPS. Later you might advance to International Rectifier if you become ready for AC line connected circuits.

http://www.irf.com/design-center/

[firethorn]

gah.. national again.. lol.. ok..

since everyone seems to be recommending them even in these "modern times" (as compared to older threads with the same suggestions ), I'll be back...

This is gonna take a while. =p

Cheers,
firethorn.

[Electrone]

I might be able to tie you up more, even. You can go to this group - http://tech.groups.yahoo.com/group/LTspice/ - (not affiliated with Linear technology Corporation) which discusses the use of the free simulator offered by LT. Linear also has a lot of nonAC line-operated stuff and that free simulator they offer comes in super handy for me.

[marce]

Its not so much recommending National, as just easy to hand information as their latest news letter covered PSU's, so the info was there.
Must admit we use some National products at work now "even in these modern times" but also products from Texas, Maxim, NXP, Linear, ONSemiconductor, Microchip etc, so there is plenty of manufacturers and info out there (we choose depending on the requirements of the power delivery system).
I agree they do (national) get more than thier fair share of mentions. Maybe its time to start a thread or wikki page on power supply related links and info as it is regeraly requested.