Designing a 12V, 10A SMPS with AC 230V Input - Request for Suggestions

[Krishhhh]

Hello everyone,

I’m currently working on designing a 12V, 10A SMPS with the following specifications:

• Input: AC 230V RMS, 50Hz (single phase)
• Output: 12V DC, 10A

I would appreciate your advice or suggestions on the following design considerations:

1. Topology:​

Which topology would be best suited for my use case? Some of the options I’ve come across include:

• Flyback, Push-Pull, Half-Bridge/Full-Bridge?

What topology would you recommend for balancing complexity, cost, and efficiency?

2. Part Selection:​

I’d appreciate guidance on selecting the key components:

• Transformer: What should I consider in terms of turns ratio, core size, and type (e.g., ferrite core)?
• Rectifiers: What type would be best for my output stage? Should I consider Schottky diodes or silicon-based rectifiers?
• Filter Capacitors: Any suggestions on choosing the right capacitance and voltage rating for the output filter?
• Voltage Regulator/Control IC: Which control ICs would be ideal for this power range?

Any specific part recommendations would be very helpful.

3. Design Process:​

What’s the best way to approach the design of this power supply from scratch?

4. Simulation Tools:​

I’ve been using Proteus for some simulations, but I’ve noticed that certain components are not available. Are there other good alternatives that might offer more flexibility or accurate results? I’ve heard of LTspice, but I’m not familiar with how comprehensive its library is for SMPS components. Any recommendations on simulation tools would be great.

Lastly, how should I validate the design after simulating it? Are there specific checks or tests I should focus on?

Thanks in advance for your advice! I’m excited to hear from you all and get started on this project.

 

[BradtheRad]

It would be easy to mention buck converter. However that involves a capacitor 500uF rated 400VDC simply to serve 20A spikes to a switch. Expensive capacitor whose useful lifetime might be short.

By interleaving two or more buck converters they can split the burden.

Or, the flyback seems like a suitable choice. It requires a transformer, although once you start considering transformers you might as well pick up a ready-made step-down power transformer (230VAC to 12VAC) and build it into an old-school power supply.

Aren't computer power supplies readily available (new or used)? 12VDC up to 10A?

 

[KlausST]

Hi,

if the only specifications are 12V@10A from 230V AC
--> They are ready to buy.

****

How to test your design?
--> the first question should be:
What are my design goals? ... in the meaning of specificaions. These usually come with numbers, units and tolerance.
This defines how you "design" your power supply
And it automatically tells you which items are being tested and how.

Klaus

 

[BradtheRad]

Are there other good alternatives that might offer more flexibility or accurate results? I’ve heard of LTspice, but I’m not familiar with how comprehensive its library is for SMPS components. Any recommendations on simulation tools would be great.

A flexible simulator is Falstad's animated interactive simulator. Components are mostly generic. I don't see it listing a SMPS controller, so I make it clock-switched. A flyback generally is designed with 50% duty cycle initially.
Everything in one screenshot. Slow scope trace at left shows 50Hz waveforms. Fast scope trace at right shows 3kHz waveforms.

Click link below to:
1) navigate to falstad.com/circuit
2) load my schematic into animated interactive simulator
3) run it on your computer.

tinyurl.com/2cwjq3ny

 

[danadakk]

First and foremost, if you want to be a competent designer self education excellent
starting point. Everything fro ap notes to YouTube lessons to improve your competency
in the language and consideration of SMPS.

There is a wealth of design ap notes and papers on web, google "smps design pdf".
This will give you basic to in-depth overview of thousands of designs. More importantly
give you a basic understanding of architectures, pros and cons, considerations, like
magnetics, semiconductor.....PCB layout choices...... Pick at least one or more papers
on magnetics, MOSFET switching, rectifier considerations, control loop stability, capacitor
selection. You dont have to read the 10,000+ docs on this, just start with a few recent
dated ap notes and papers. A week of this will do wonders for your starting point.

A good book on Magnetics :

Trilogy of Magnetics: Design Guide for EMI Filter Design, SMPS & RF Circuits - Anna’s Archive

Thomas Brander, Alexander Gerfer, Bernhard Rall, Heinz Zenkner Cover Title Imprint Content Preface Thank you! The Authors I Basic principles 1 Basic principles of Swiridoff Verlag

annas-archive.org

Tools :

WebDesigner+ Design Tools

www.onsemi.com

WEBENCH-CIRCUIT-DESIGNER Design tool | TI.com

View the TI WEBENCH-CIRCUIT-DESIGNER Design tool downloads, description, features and supporting documentation and start designing.

www.ti.com

Many more. Pick a vendor, and focus on that tool. Most semi vendors have libs of
designs that can be imported into tools, like LTC Spice, Simetrix, Cadence...... that
you can look at working examples, play with to see effects. Personally Simetrix,
which was the tool of choice at Analog Devices before the Linear Technology
acquisition, best in class in terms of ease of probing and breadth of probe types.

Once you focus a little your questions will be more focused versus the very broad
initial post you provided. That way this forum, which in general does not do complete
designs, can aid in its experience expertise for working on specific problems.


Regards, Dana.

 

[Krishhhh]

A flexible simulator is Falstad's animated interactive simulator. Components are mostly generic. I don't see it listing a SMPS controller, so I make it clock-switched. A flyback generally is designed with 50% duty cycle initially.
Everything in one screenshot. Slow scope trace at left shows 50Hz waveforms. Fast scope trace at right shows 3kHz waveforms.

View attachment 193791

Click link below to:
1) navigate to falstad.com/circuit
2) load my schematic into animated interactive simulator
3) run it on your computer.

tinyurl.com/2cwjq3ny

Thanks for the design! Really appreciate it. I have a doubt could you explain how the design was done? or any reference for how can we design the flyback converter. Additionally i will be trying to simulate the same design in proteus replacing the switch with an NMOS and using a 555 timer to generate the 3kHz pwm signal will this suffice?

 

[BradtheRad]

My flyback schematic is just a starting point in order to start somewhere. It isn't necessarily optimum. It illustrates your high voltage side can use wiring suited for a handful of Amperes. Yet notice the secondary carries current bursts upwards of 60 Amperes. A more satisfactory topology may turn up.

Transformer parameters are determined by switching frequency. Henry value is chosen to allow current to ramp up the flux field to the necessary level during the first half of a cycle. Then the flux field induces current flow in the secondary during the second half of the cycle.

Use your chosen switching component, either high-side or low-side depending on whether you use a P or N-device. My schematic is a crude flyback, lacking feedback and regulation section.

 

[danadakk]

These might help -

https://www.ti.com/lit/ml/slup127/slup127.pdf

https://www.fujielectric.com/products/semiconductor/model/power_supply/tool/box/pdf/Fly-Back_transformer_Design_Rev_1_0_E.pdf

https://www.ti.com/lit/pdf/ssztcu9

https://www.infineon.com/dgdl/an-1024.pdf?fileId=5546d462533600a401535591115e0f6d

https://media.monolithicpower.com/mps_cms_document/a/n/an-intro-to-flyback-converters-para-topo-and-controllers_r1.0.pdf

 

[D.A.(Tony)Stewart]

Is your load a motor or LEDs? It makes a big difference..