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General Discussions => Drawing Board => Topic started by: pucho812 on February 06, 2019, 02:31:04 PM

Title: SMPSU design and theory
Post by: pucho812 on February 06, 2019, 02:31:04 PM
Anyone have some good places too learn about SMPSU design or can recommend a place that would do the heavy lifting of designing a SMPSU to set specs?
Title: Re: SMPSU design and theory
Post by: JohnRoberts on February 06, 2019, 02:34:59 PM
I have found some decent tutorials in chip manufacturer's application notes.

JR
Title: Re: SMPSU design and theory
Post by: pucho812 on February 06, 2019, 02:36:59 PM
I have found some decent tutorials in chip manufacturer's application notes.

JR

o.k. will look into  app notes from T.I. and others
Title: Re: SMPSU design and theory
Post by: pucho812 on February 06, 2019, 03:01:29 PM
I also found this...  8)

https://www.poweresim.com (https://www.poweresim.com)
Title: Re: SMPSU design and theory
Post by: benb on February 06, 2019, 03:35:51 PM
I remember using a LT1072 and reading "Switching Regulators for Poets" about 30 years ago. I think I was lucky in that these were some of the first all-in-one chips where the datasheet says use these resistors, these capacitors, this part # for the catch diode, this value and current rating inductor,  and if your traces, especially the big current-carrying ones, are short and fat it'll work. Before then it was more of a black art.

I'm not sure why you want to do this, it seems there are plenty off off-the-shelf SMPS modules around thesedays, not just from the power line, but for any x range of voltage input and y range of voltage output, and if they're from good manufacturers, they're speced for ripple voltage and stuff.
Title: Re: SMPSU design and theory
Post by: john12ax7 on February 06, 2019, 03:49:18 PM
Mean well seems open to doing custom designs at reasonable volumes,  there have been some threads on here about it.

Or do you want just a raw design that you would assemble yourself?
Title: Re: SMPSU design and theory
Post by: JohnRoberts on February 06, 2019, 04:25:14 PM
I remember using a LT1072 and reading "Switching Regulators for Poets" about 30 years ago. I think I was lucky in that these were some of the first all-in-one chips where the datasheet says use these resistors, these capacitors, this part # for the catch diode, this value and current rating inductor,  and if your traces, especially the big current-carrying ones, are short and fat it'll work. Before then it was more of a black art.
My first work effort involving a DC-DC switching PS was in the late 60's  some 50 years ago... 

IC controllers for switching PS did not exist back then, let alone app notes.  The project I worked on was a PS for a DSRV (deep submergence rescue vehicle) a specialty navy vessel, and the PS was no doubt slick for the day.  I was working at MITIL but the design was from a Raytheon engineer who tricked a very early linear voltage regulator (LM100) to oscillate  and act as a brain for a switching regulator, but surely crude by today's standards.  As I recall the switching transistors were not very robust back then and would release their magic smoke if we looked at them crosseyed. 

I was just a junior technician and a MIT grad student was the project engineer. Pretty much he would blow it up, and I would get it working again as far as we were though the design. After several months he returned to full time classes and instead of giving me another junior engineer to break in, they just had me finish the project alone (I had learned a lot from troubleshooting and repairing it). I was drafted into the army before the project was completely signed off (we were just proving out that the design worked), but they managed to finish the project without me.  :o

The DSRV was a real Navy program for extracting crew from disabled submarines (it was showcased in the "Hunt for Red October" movie. )
Quote
I'm not sure why you want to do this, it seems there are plenty off off-the-shelf SMPS modules around thesedays, not just from the power line, but for any x range of voltage input and y range of voltage output, and if they're from good manufacturers, they're speced for ripple voltage and stuff.
For a new product design, one might be tempted to drop in a UL approved PS module to avoid that whole can of worms (dealing with mains voltages wrt UL approval).

That said these are useful design concepts to learn. Hint: PC layout matters (follow the current).

JR
Title: Re: SMPSU design and theory
Post by: abbey road d enfer on February 06, 2019, 04:39:10 PM
Anyone have some good places too learn about SMPSU design or can recommend a place that would do the heavy lifting of designing a SMPSU to set specs?
Check this company
https://ac-dc.power.com/products/topswitch-family/
I've never used their products, but each time I get their info I am amazed at the degree of user-friendlyness their products seem to pack.
Title: Re: SMPSU design and theory
Post by: pucho812 on February 06, 2019, 06:43:54 PM
I'm not sure why you want to do this, it seems there are plenty off off-the-shelf SMPS modules around thesedays, not just from the power line, but for any x range of voltage input and y range of voltage output, and if they're from good manufacturers, they're speced for ripple voltage and stuff.
Yes there are some good off the shelf options if I have the space to accommodate them  in a chassis. While I would like to go that route, there are some that do not provide me with the voltages I require.

Mean well seems open to doing custom designs at reasonable volumes,  there have been some threads on here about it.

Or do you want just a raw design that you would assemble yourself?
I would prefer a preassembled supply. I have some requirements that currently are not in the off the shelf options due to size or voltage or both.

Check this company
https://ac-dc.power.com/products/topswitch-family/
I've never used their products, but each time I get their info I am amazed at the degree of user-friendlyness their products seem to pack.

I will look into them thanks.

I am not looking to reinvent the wheel just gain a better understanding so I can approach a company and say I need a PSU that does these things, can you make it.  ;)