220v to 3.3v

Thread Starter

mukams

Joined Apr 12, 2020
12
I would like to power my esp and looking for a mini compact Ic regulator which could output 3.3v,5.5v from input 220v.Any suggestions
 

schmitt trigger

Joined Jul 12, 2010
464
I also second the suggestion of a ready-made adapter.
Otherwise a transformer, bridge rectifier and capacitor filter, followed by a three terminal regulator.
 

Thread Starter

mukams

Joined Apr 12, 2020
12
Yes, it's 220v to Dc is there is an alternate rather than a transformer. wanted to design a PCB with minimal components for convert. what about Mp150g
 

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DickCappels

Joined Aug 21, 2008
7,742
I also endorse the idea of using a cheap phone charger. You can connect a three terminal 3.3 volt regulator to the 5V output. I used to make my own power supplies but for the last almost 20 years I have been buying wall warts. I figure somebody already went to a lot of trouble to make it safe, both electricity wise and fire wise. I really want to pay attention to my project rather than the power supply.

I have worked at computer companies and have see first hand what goes into considering the safety of a design. It too much like work to be fun.
 

Thread Starter

mukams

Joined Apr 12, 2020
12
actually, I would need a schematic voltage regulator so that I can design my other IoT boards. As these boards are compact and easily fit inside a switch getting an alternate charger shows the charger wire. My old design was having these issues now I design my other board which works fine in switching lights by phone app the only issue is space as I require a min compact design so that I can hide the board at the back of the switch box.
 

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andrewmm

Joined Feb 25, 2011
1,757
You say your after doing your own layout ?

What is your experience at 240 V AC powered layout design ?

Even choosing the wrong type of safety capacitor can in the long term lead to 240 V being applied to say the DC "ground" line,

Is it worth the risk ?
 

MisterBill2

Joined Jan 23, 2018
9,304
One additional consideration is the effect of a component failure on the output voltage. 220 0r 240 volts can punch through a failing IC and deliver quite a few watts to that 3.3 volt load, at best just destroying it, at worst starting a fire. There is a reason why it is so challenging to try finding the maker of those cheap phone chargers.
 

Thread Starter

mukams

Joined Apr 12, 2020
12

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MisterBill2

Joined Jan 23, 2018
9,304
For building mains powered supplies I always use a transformer for isolation. And I verify the isolation of the manufactured switcher supplies that I use because I consider mains isolation to be important. Especially in small systems that are not conveniently accessible safe operation is important.
It sounds like you are creating some interesting projects. Other here might also find them interesting if you were to share some designs.
 

bigjoncoop

Joined Feb 1, 2019
166
@mukams

Please consider just using an off-the-shelf ready-made power adapter. Like mentioned above. You could just use an old phone charger etc...

I've been an electrician for about 25 years. If you're not 100% positive and confident with what you're doing when it comes to A/C voltage, please do not mess around with it. It could instantly hurt you or worst kill you, or burn your house down. ( I'm assuming you came here for advice since this type of stuff is new to you..) So please take our suggestions seriously.

Most of us have a closet / junk drawer full of old power adapters. Just look for one that has a 3.3v output. Or if you're really set on designing something yourself, find an old power adapter that has a 24v, 12v, 9v, or 5v output then create your own voltage regulator circuit to give you your 3.3v....

If you use an old power adapter to give you a low voltage DC output then you can make a voltage regulator a ton of different ways. The most simplest would be using only 2 Capacitors and a LD1117V33 Linear voltage regulator. And there are literally hundreds of substitutes for that regulator. You could build something for literally $1...

But have fun with it. Just be careful. I guarantee more than 1/2 of the people on here or hobbyist around the world are great at what they do when it comes to DC circuitry but will not miss whatsoever with a A/C
 
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