Question about rectifier bridge

[wat]

I would like to find any kind of rectifier bridge data sheet which can convert 220AC to 12V and 5V. However, I am hardly to find any of this. Can anyone provide me with the circuit.
P.S. The rectifier bridge is for small electric appliance

 

[bloki]

Such rectifier bridge would use thyristors and control circuit. But I think you should use transformer to change voltage from 220V to 12V and 5V. Then you will use ordinary bridge rectifier. It is cheaper and simpler.

 

[Nigel Goodwin]

Yes, you need a transformer to drop the voltage, then a bridge rectifier to rectify it. There are various crude methods of dropping the voltage, but mostly only for very low power loads, and they are somewhat dangerous!.

 

[wat]

I would like to convert AC voltage(220ACV) to DC voltage(12DCV) first. Then I use transformer to step down the 12 V to 5 V. Do you have any comment on this idea?

 

[hjl4]

It depends on how much current is drawn,on 5v side.
Personally I would use a 7805 voltage regulator tapped directly into the rectified 12v supply.(of course, after the filters)
It has always worked for me.

 

[Styx]

Well the only way is to rectify and then use a SMPS to step-down the DC voltage

 

[hjl4]

Wat

First transformer then bridge rectifier, then filter, then voltage regulator.
Very simple.

This gives you 12vdc rail, and 5vdc regulated.

Make sense?

If I had time, I would draw it out, but I'm sure someone here already has it done, and maybe will reply with schematic.

Good luck.

 

[Styx]

I would like to convert AC voltage(220ACV) to DC voltage(12DCV) first. Then I use transformer to step down the 12 V to 5 V. Do you have any comment on this idea?

Well just read it a bit closer.

YOu want to convert AC-220V to DC-12V: transformer downto ~10VAC then rectify.

you then want to use a trasnformer to step down 12VDC to 5VDC, a trasformer does not work on DC

 

[hjl4]

Styx,

you can tell he is a bit confused.

You know that what he means , he wants a 12vdc supply rail, and a 5vdc supply rail.

The way I suggested is proper.

If he wanted 10vac, I'm sure he would of stated it.
He is lost thinking he has to transform the mains and then transform again to get dc 12v and then again for 5vdc.

 

[Nigel Goodwin]

I would like to convert AC voltage(220ACV) to DC voltage(12DCV) first. Then I use transformer to step down the 12 V to 5 V. Do you have any comment on this idea?

Transformers ONLY work on AC, and they are one of the most efficient electronic components you can use - so your idea is rubbish!. Use a transformer directly from the 220V down to what you want - cheap, efficient, and easy.

 

[4electros]

I would like to find any kind of rectifier bridge data sheet which can convert 220AC to 12V and 5V. However, I am hardly to find any of this. Can anyone provide me with the circuit.
P.S. The rectifier bridge is for small electric appliance

search for datasheets using think:
https://www.datasheet4u.com/

 

[hjl4]

wat,

why do you post for help, and then you disappear??

Is it because our knowledge is not good, or do you imperatively need to have a schematic?

Don't expect too much with so little, or confusing demands.

I told you what to do, and yes, if you googled for "psu schematic", you would get hundreds of hits.

Maybe this was a waste of time.

Have fun.

 

[wat]

Sorry, i am so late to come....I think you are all professionals and I am a little bit shame on me.
I have found one named "TOPSwitch-GX" which can help me to fulfill my objective. I have use the provided circirt to step down 220ACV to 12DCV with 2.5A. Then I use voltage regulator to convert 12DCV to 5 DCV with 1A. I think I have found the answer I wanted. Thank you all brothers~

 

[wat]

www.powerint.com/topgxproduct.htm
Here is the link :lol: :lol:
Thanks once again

 

[gerenis]

:!:
Wat!

The Topswitch-GX is a component for use in Switch-mode power supplies (SMPS). It is intended for use by professional SMPS design engineers. Not a toy for hobbyists! It will not transform 230VAC to 12VDC!!!
:!:
If you do not have electronics education, i SRONGLY RECOMMEND QUITTING POWER SUPPLY TWEAKING BEFORE YOU SET YOUR APARTMENT BLOCK ON FIRE OR HURT YOURSELF.
:!:

For those who have the basic knowledge and some experience in electronics,
I have drawn a conventional regulated power supply you can use: go to
**broken link removed**

THE MOST IMPORTANT PART OF A POWER SUPPLY IS THE FUSE AT THE INPUT. IT MUST HAVE APPROPRIATELY LOW AMP RATING, TO PREVENT THE RISK OF FIRE.
For small current consumption devices it is usually OK to use 100mA/250V fast or 50mA/250V slow-blow fuse.

The primary of the transformer and the fuse are at DANGEROUS voltage (see dotted box in schematic).
All components on the low voltage side of the transformer must be well separated from the MAINS VOLTAGE SIDE TO PREVENT ACCIDENTAL SHORT CIRCUIT TO MAINS VOLTAGE AND RISK OF ELECTRIC SHOCK.

Most commercial plug-in adaptors have the same circuitry up to C1. So if you have such an adaptor with 18VDC to 24VDC output, you only need to insert the C2-C4 and the 2 regulator ICs and you're done.