You said you want 5V at 2A but you did not say if it is AC or DC so we assumed DC. If you feed 5VAC into a circuit designed for 5VDC then the circuit might explode or smoke and burn up.

 

You said you want 5V at 2A but you did not say if it is AC or DC so we assumed DC. If you feed 5VAC into a circuit designed for 5VDC then the circuit might explode or smoke and burn up.

You are right, edited. Thanks!

 

If you can find any of the older Wall-Warts (non SMPS), often in flea markets cheap, the have a mains transformer in them that can be salvaged and a simple 3 pin regulator added if necessary.
I have quite a few obtained this way.
Max,

 

If you can find any of the older Wall-Warts (non SMPS), often in flea markets cheap, the have a mains transformer in them that can be salvaged and a simple 3 pin regulator added if necessary.
I have quite a few obtained this way.
Max,

Great advice, thanks!

 

Thank you all for advices! I got the big picture for anyone looking for the answer - some power supplies have high frequency switching transformers that are much smaller yet more complex than isolation power transformers (for example with 50Hz).
Documentation found in this thread.

 

Thank you all for advices!

Transformers seem to be getting more expensive and harder to find these days and working with line voltage isn't for some novices.

With an AC to AC wall wart, you can design your own power supply without having to fiddle with line voltage. Back in the 70's, I built a box with a half dozen different tansformers I had and used it for building power supplies. These days, I use wall warts or USB for power sources most of the time.

 

Whats wrong with a good old fashioned 220v to 5v transformer , a rectifier, a capacitor and a linear regulator?
Simplest and cheapest option and its known to work
Sometimes people try to be too clever when a simple solution is staring them in the face.
I can buy all the parts from my local electronics store or ebay no trouble.

 

Whats wrong with a good old fashioned 220v to 5v transformer , a rectifier, a capacitor and a linear regulator?
Simplest and cheapest option and its known to work
Sometimes people try to be too clever when a simple solution is staring them in the face.
I can buy all the parts from my local electronics store or ebay no trouble.

You may have ignored the following from the TS original post:

The issue is that I manage to find only PRICEY, HUGE TRANSFORMERS like this.

It is not enough to perform the voltage transformation -- it has to be done in a small, light package. Unfortunately that represents an engineering challenge, or a purchasing challenge.

 

I dont think that transformer you referenced is neither huge nor pricey.
Unless you find on the road side a small walwart supply, then a SMPS is going to be far more expensive than a linear type circuit
Also that transformer is the correct size and rating for your application. It cant be smaller as the power is related to the core size.
And an off the shelf SMPS is not so small.

 

I dont think that transformer you referenced is neither huge nor pricey.
Unless you find on the road side a small walwart supply, then a SMPS is going to be far more expensive than a linear type circuit
Also that transformer is the correct size and rating for your application. It cant be smaller as the power is related to the core size.
And an off the shelf SMPS is not so small.

Aside from your double negative which implies something I don't think you intended; I actually looked for one that was better, and there weren't any I could find that were not PC board mounted. Never mind for a better price,

 

Order a 5V wallwart or other power supply from the UK. Their household power is 220V so small supplies should be common and inexpensive.
Paul

 

In post #18:

Why not just use a commercially available adapter. I bought a 5V, 4A adapter for $5-6 at a second hand store. I have some 5V 2A adapters that came with Linksys ethernet switches, but I wouldn't trust them to provide 2A.

In post #19:

Thanks for answering! This is just for home work and theory. I'm not looking for ready to use models..

Order a 5V wallwart or other power supply from the UK. Their household power is 220V so small supplies should be common and inexpensive.

The thread does span 2 pages, but the OP has already addressed your comment.

 

How about this?
https://www.antekinc.com/an-0206-25va-6v-transformer/

Or, if you don’t mind a 12v toroidal, I have a spare new one that I will give you.

Brent

 

How about this?
https://www.antekinc.com/an-0206-25va-6v-transformer/

Or, if you don’t mind a 12v toroidal, I have a spare new one that I will give you.

Brent

Doesn't he want 24VAC?

 

Toroidal is easy to customize though, usually.
Just put a small overwind on.
Max

 

OP: “Hi all, I'm interested in assembling a circuit that will be capable of CONVERTING 220V TO 5V@2A 10W (Edit: AC TO DC)”

Did it change from the original desire for 5VDC?
Either way, the transformer that I have can be wired to either 110 or 220VAC input, and 12 or 24VAC output.
Which would rectify to ~17 or 34VDC, or can even be used for center tapped output to give +17 & -17VDC.

Brent

 

if you don’t mind a 12v toroidal, I have a spare new one that I will give you.

That's very nice of you. I noticed that neither of you has included your location in your profile. Hopefully you and the OP aren't too far away from each other.

 

That's very nice of you. I noticed that neither of you has included your location in your profile. Hopefully you and the OP aren't too far away from each other.

I’m in Damascus Oregon USA, but I wouldn’t mind shipping it to where ever the OP is.
Sounds like he is wanting do this as a learning exercise.

Brent

 

Sounds like he is wanting do this as a learning exercise.

I really appreciate your eager to help!
I posted this thread just to get some background info for my research as a newbie to the field.
As I mentioned my goal was to find explanation for how could power supplies be made so small.
I'm not intending to build one though, since I have too little knowledge about HF transforming circuits and try to avoid risking myself.

I highly honor your replies and happy to say I have learned a lot!
Thank you for everyone and especially your kindness.

As a reminder -

I got the big picture for anyone looking for the answer - some power supplies have high frequency switching transformers that are much smaller yet more complex than isolation power transformers (for example with 50Hz).
Documentation found in this thread.