SMPS Design

[AtomSoft]

I need to make my own 5v SMPS like those used in IPAD and CELLULAR chargers. Transformer-less i guess.

I know these can cost a pretty penny to make when not in bulk but i need it. It has to be of my own assembly. I have to be able to source the parts and put it together. Any thoughts? Links?

250mA to 1A would be awesome.

 

[ChrisP58]

I assume you are talking about an AC line powered charger? If so, there is no way to make a safe one without a transformer.

I would start looking to see if there is a reference design or development kit close to your needs.

You might find something here:**broken link removed**

 

[AtomSoft]

Yes a AC charger. I dont mean completely without a transformer. Just those BULKY ones.

I want to make this>.... (JUST FOUND THIS LINK)
**broken link removed**

 

[AtomSoft]

WOAW check this out!
**broken link removed**

Thats what im talking about!

 

[tvtech]

Hi Atom

FWIW..leave SMPS design and everything to pro's....

Don't go and meddle. One day I will maybe tell you a story about how you can burn your fingers....
And waste money. And "design a SMPS"......

Repair is hard enough...design is impossible. A "dark art"......

A little caution here from a Dude that has traveled that rocky road. And absolutely hates **** SMPS designs. And applauds good ones.

Problem is the good ones don't break...so you never get to know them.
And the shitty ones you fix all the time become your bread and butter.....

Thinking back now and with all I do daily with cheap TV repairs....well designed SMPS are a boss.

Still, on any SMPS no matter how brilliant the design, the weakest link is the Main Smoothing Cap...
If it pops, all goes to hell. On a TV....hum bar. Can see it...

On other things, not really noticed. Until the SMPS decides to die too.

My SMPS cautions to people are well founded. Unfortunately they are the future.

I really don't know what else to say except a more Linear approach ????

Maybe a mix of Linear and SMPS???

tvtech

 

[AtomSoft]

I dont really want to learn on the HOW TO DESIGN. I want to build one. I plan to make some pcbs and would be nice to be able to POWER it straight from MAINS instead of buying little supplies for each. Not only does it save on time sourcing cheap reliable supplies it saves on space. Some of these projects i work on need to go behind stuff and hidden in tiny spaces. If i can make my entire project 2x3 including the supply then why not?

 

[tvtech]

I dont really want to learn on the HOW TO DESIGN. I want to build one. \

Hi Atom

Search the NET then. And see what you come up with. Nobody likes to touch SMPS...they are bad boys......worst part is wanting to build one without understanding what you are doing.

By the way, I have around 94 Viper 50's for sale. Brand new. Original ST.

I used the original Viper software from ST. Detailed instructions of how to make them fly....that was around 2001. After blowing five up...only one unit cut it.

And it was good until one day it blew up too. My chopper transfomers came from NZ.

Nobody here new what I was on about...

So, as a guy who has been through the stuff, leave SMPS alone.

You WILL burn your fingers by trying to build them. The chopper Transformer is the Boss of a SMPS. You have to get it right.

Sidenote: My Viper 50's will be worth a fortune one day. Holding onto that dream

Regards,
tvtech

 

[AtomSoft]

heh, im sure if i follow an exact design and part list from a reference design from some place like ST i shouldnt have an issue. If i do ill be sure to take it up with them.

 

[tvtech]

heh, im sure if i follow an exact design and part list from a reference design from some place like ST i shouldnt have an issue. If i do ill be sure to take it up with them.

We could not get the Chopper Transformers wound correctly with consistency. The Viper software showed how the PCB layout must look. I followed it to the letter. Picture perfect.

^^^ Atom, don't kid yourself. Believe me.....I(We) tried. And I do not give up easily..

Think about this: Not your normal Mains transformer running @ 50/60 Hz that can be wound easily. Other things to consider:

1. Core Material.
2.Switching speed(dealing with around 100 Khz here).

And yes I said 100Khz. Not a typo.

So much quick switching, so much happening.....in the blink of an eye all goes to hell/heaven.

It's not ST's fault. There are literally thousands/millions of these out there still. Reliable as ever. I did not know enough then.
Could not get the SMPS Transformer wound correctly.

And that is that. And a lesson learned.

Typical of me though....always trying the cutting edge

And all this took place around 2001 or 2002....

I have changed though.....sort of like mediocrity right now....instead of trying to lead ....I shut up and listen rather. And try and prevent others making my mistakes.

Saving you time. Saving you money.

Regards,
tvtech

 

[AtomSoft]

Im talking about buying everything flat out. Im not winding any transformers and im not coding any controller. Im using a FULLY WORKING DESIGN and just placing it onboard instead of off board

 

[AtomSoft]

For instance, are you telling me if i build this i will fail?

**broken link removed**

transformer is here: https://www.digikey.com/product-sea...ing-converter-smps-transformers/787670?k=EE13
Im sure i can find the rest of the parts

 

[tvtech]

Im talking about buying everything flat out. Im not winding any transformers and im not coding any controller. Im using a FULLY WORKING DESIGN and just placing it onboard instead of off board

Well then, good for you. I am not a peanut trying to discourage you...just the opposite.....

I wish you well. Go for it

tvtech

 

[AtomSoft]

I wont try it I think it would be a waste of time. Id be better off buying some cellphone chargers and hot glueing them to a PCB. I am not crazy enough to waste time and money, i do like to be a pain in the butt tho Thanks tvtech

 

[tvtech]

I wont try it I think it would be a waste of time. Id be better off buying some cellphone chargers and hot glueing them to a PCB. I am not crazy enough to waste time and money, i do like to be a pain in the butt tho Thanks tvtech

I am not trying to discourage you. Just talking about my stuff.

SMPS is an unforgiving *******. Being fixing them for too long now.

All the best,
tvtech