Hello everyone.
I'm looking for SMPS circuit with high efficiency to drop from 220Vac to around 12Vac that can supply around 1.5Apms.
Please help me to find a circuit matches the requirements above.
And another question, if i'll supply to this circuit just 110Vac, i'll still get 12Vac? or just 6Vac?
Thanks in advance.
A SMPS will typically deliver a DC voltage. If you just want 220 VAC to 12 VAC why not just use a simple transformer or AC output wall wart transformer. If you put 120 VAC in a 220 VAC transformer designed for 12 VAC out you will get 6 VAC. What's the reasoning for a switch mode power supply? You are only looking for 1.5 amps.
Sorry, my mistake, i need 220Vac to 12Vdc, so SMPS is great for this purposes.
even at 1.5Amps transformer is much bigger that SMPS, less efficient and cost more.
Sorry, my mistake, i need 220Vac to 12Vdc, so SMPS is great for this purposes.
even at 1.5Amps transformer is much bigger that SMPS, less efficient and cost more.
OK, then if SMPS is what you want you can run out and buy **broken link removed** with an input voltage anywhere between 85-264 Vac. Excellent specifications as you can see. It carries a price of about $130 USD.
Option #2
You can hack an old ATX home computer SMPS for considerably less money. Sort of overkill.
Option #3
Just use a simple everyday wall wart. Which has been suggested.
You can use an integrated converter chip, e.g. FSQ0370, FSDM0565. Just needs a transformer and a few support components.
You can set the thing up to run happily with a wide range of input voltages, e.g. 85-240VAC (or whatever) and to provide the same output voltage (e.g. 12VDC).
Of course, it's as safe as you make it. I would trust one I made.
Yes, it's likely going to be more expensive to make one yourself than to buy a mass-produced consumer item, but it really depends on what the goal is as to which approach to choose. An easy approach for an SMPS converter is incorporating the aforementioned IC.
Thanks you all, but i searching for a circuit to SMPS like in the WallWart.
i know many other options, but i want to build it myself for learning more about control circuit in aSMPS.
If you are good at electronics (read: you will not blow yourself up) look at Power Integrations. They do a whole ton of chips for this exact purpose. The LNK link switches are the cheapest, but non isolated. Some transformer manufacturers have teamed up with them to provide off the shelf solutions for the magnetics too
The standard component that old wall warts used to use is the 3842/3844 from ST.com with a TL431 to close the feedback loop. Things have moved on in recent years and Power Integrations have sewn up the market for the single chip solutions.
FSDM0*65RE and FSQ0*70RNA on Ebay cost around 10$ each.
But 3842 and TL431 cost less than a dollar together!
So if i can built SMPS 220V to 12V 1.5Amps from 3842 and TL431, it will cost just few bucks.
simonbramble, do you have the circuit that can do the job?
thanks for the help.
Personally I would look at the Link Switches and Top Switches from Power Integrations. The 3842 is very old and needs a lot of (finely tuned) components around it and it might not work stabily at the end of the design. The PI devices have all the compensation built in, so should work first time. Have a look on their website for hundreds of reference designs
I don't so worry about safety because all the system will be closed, hope in epoxy, and no one will can't touch it.
I searching for design with efficiently over 90% and as much cheaper as can.
Just buy a Chinese 12v SMPS 1.5A wall-wart from ebay and pull out the little 90% efficient PCB and set it in epoxy then?
It sounds to me that its not really about learning as you juts want to make one unit and then it's set in epoxy and finished? Just buy one for $10 and save yourself hours of blown parts and possible lethal danger.