12V 10A SMPS. Looking to choose topology.

[salova322]

12V 10A smps. please help me to choose topology

Hello, I want to design a SMPS with an input of 220V 50Hz, an output of 12V 10A. Can you help please choose the topology? Which will be simpler? Which is more effective? And can you help to choose the conversion frequency?

 

[KlausST]

Re: 12V 10A smps. please help me to choose topology

Hi,

It is an output power of 120W.
I assume a flyback is suitable.
But for this power range I assume you need a PFC.

I'd buy one, because I couldn't develop and produce it cheaper than the ready to buy ones. 12V, 10A is a common power range.

Why do you want to design your own power supply?

Klaus

 

[salova322]

Re: 12V 10A smps. please help me to choose topology

Hi,

It is an output power of 120W.
I assume a flyback is suitable.
But for this power range I assume you need a PFC.

I'd buy one, because I couldn't develop and produce it cheaper than the ready to buy ones. 12V, 10A is a common power range.

Why do you want to design your own power supply?

Klaus

Thank you for answer. Why not a forward topology? Why I should use a PFC? Passive is good? This is for my studies.

 

[KlausST]

Re: 12V 10A smps. please help me to choose topology

Hi,

Why not a forward topology?

I didn't say that other topologies are not suitable. Maybe forward is suitable, too.

Why I should use a PFC?

Because of regulations. It depends on the country where you live.
In Europe there is IEC61000-3-2.
Read through your country's regulations.

Passive is good?

Passive PFC? Maybe, if it can fulfill the requirement of your counrty.

Klaus

 

[E-design]

Re: 12V 10A smps. please help me to choose topology

This power requirement should be a good fit for a dual switch forward converter.

Update:

Removed RC snubber from primary winding in diagram.

 

[CataM]

Re: 12V 10A smps. please help me to choose topology

Because of regulations. It depends on the country where you live.
In Europe there is IEC61000-3-2.

Regulations is the story at low power. At high power it is impractical for the bulk capacitor due to the huge current it must withstand.

- - - Updated - - -

E-design, I think snubbing the secondary makes more sense than the primary? Especially at high duty cycle, would you agree ?

 

[E-design]

Re: 12V 10A smps. please help me to choose topology

CataM, I used/modified the transformer from another design with a single switch and snubber. I forgot to remove that, since there is no need for a snubber with the dual switch. Sometimes it is necessary to damp the output filter with an additional RC combination to prevent ringing at start-up. I updated the previous diagram now.

 

[CataM]

Re: 12V 10A smps. please help me to choose topology

since there is no need for a snubber with the dual switch

I understand that this simulation is merely conceptual since the components used are ideal, but now that we brought up the snubber topic, I think there is a need for snubber across the secondary diode which does not have a name in your schematic.

 

[E-design]

Re: 12V 10A smps. please help me to choose topology

I agree there may be instances where you need a snubber across the diode to prevent reverse breakdown due to ringing. For safety in this application, you will typically use a 150 V schottky or 200 V ultra fast diode.That is one reason we see more designs start to use SiC diodes, to do away for the need for snubbing over the diodes.