My iPhone and Samsung S8 each have a wall wart for charging. They are super hackish devices. I can't believe Apple is trying to sell those things when they look like a DIY project from a third grader.

As far as safety, most parents let their kids handle these dangerous wall warts and thousands (maybe millions) of people are killed by them each day. Bad parents!

Your iPhone isn't 120v equipment. The reading comprehension required for this is at about a grade 7 level. Thanks but no thanks

 

And around we go. You have been already given the answer. Wall wart. It is the cheapest, easiest solution. How on earth is a wall "hackish"??? Thousands of some very fine consumer electronics use them.

Read.

 

Does your tv have a second plug for a wall wart? This thread just got very stupid. Seems to be how this forum rolls unfortunately.

My receiver below the TV has two - one switched and one not. The TV doesn't have one but I split the power cord to add a power cord that lets me hang the amazon fire stick back there without an extra cord.

 

Your iPhone isn't 120v equipment. The reading comprehension required for this is at about a grade 7 level. Thanks but no thanks

If that is true, how does my iPhone's wall wart find the OUTLETs that are not 120V?

 

I don't own any devices with extra plugs, but some have sockets...

 

Your iPhone isn't 120v equipment. The reading comprehension required for this is at about a grade 7 level. Thanks but no thanks

Read.

Humm. Seems to me that there are a whole lot of really smart people that at having trouble figuring this one out. Maybe it isn't a problem with reading comprehension, rather the person writing it?

 

I could, but i would have to open the housing and solder wires from the equipment power in, to the wall wart terminals and mount the wall wart pcb somewhere inside the enclosure. I feel like that would be exceedingly hackish.

Transformer power would be from the contact inside the eqiupment where the plug first distributes AC power inside. So basically just to a standard AC plug.

Why? This is what you have not explained. Just install a power receptacal if need be.

 

5 seconds of searching.

https://www.ebay.com/itm/Pulse-Dime...342439?hash=item4674815027:g:KoMAAOSwVgtZ2AVt

No receptacle needed no smashing apart a wall wart.

 

There is room for a transformer, but its not practical to plug in a wall wart, when the equipment has its own power source, I want the MCU to use the same power source.

This is a vote for transformer no?

I think you don't realize that a transformer is only part of a power supply. Yes, you can wire in a transformer but as has been pointed out earlier, you than need a rectifier, filter capacitor and regulator circuit. A "wall wart" will have all that inside it (if it is a regulated DC type). Either an iron core transformer and linear reg. or ferrite transformer and switch mode. Both have transformers. Using a transformer (as part of the power supply) is really to only practical way to get the isolation. Old systems of WW2 vintage did use dynamotors, that is an electric motor driving a generator, but that is not the way to go nowadays except for specializes applications.
I have used wall warts as an internal power supplies in the past. You can cut the socket off a power lead and wire that in or use a chassis mounted socket or select a "wall wart" that has a plug in power lead. Of course you could build a complete power supply yourself but if you don't know what you are doing you run a risk of blowing up the rest of the circuit.
Yes, some of the comments are a bit less than helpful, but that usually comes as a response to a question that has been given an answer that is ignored. If you don't want to conciser the advice offered here, why ask in the first place?
And really, more info of your application, with pictures could be a great help. As I've asked many times on this forum, "why is it so had to get full information from thread starters?"

 

Why? This is what you have not explained. Just install a power receptacal if need be.

Yeah, if there's room in the enclosure to add a receptacle, then using cheap, readily available wall warts seems the easiest way.

If not, why not just use a proper isolated power supply that will probably produce cleaner power and will certainly be more efficient than what you can build yourself. Here are some examples from DigiKey, starting just under $9.00:

https://www.digikey.com/products/en...v127=1312&pv127=115&pv1525=62&pv69=6&pv69=178

 

I think you don't realize that a transformer is only part of a power supply. Yes, you can wire in a transformer but as has been pointed out earlier, you than need a rectifier, filter capacitor and regulator circuit. A "wall wart" will have all that inside it (if it is a regulated DC type). Either an iron core transformer and linear reg. or ferrite transformer and switch mode. Both have transformers. Using a transformer (as part of the power supply) is really to only practical way to get the isolation. Old systems of WW2 vintage did use dynamotors, that is an electric motor driving a generator, but that is not the way to go nowadays except for specializes applications.
I have used wall warts as an internal power supplies in the past. You can cut the socket off a power lead and wire that in or use a chassis mounted socket or select a "wall wart" that has a plug in power lead. Of course you could build a complete power supply yourself but if you don't know what you are doing you run a risk of blowing up the rest of the circuit.
Yes, some of the comments are a bit less than helpful, but that usually comes as a response to a question that has been given an answer that is ignored. If you don't want to conciser the advice offered here, why ask in the first place?
And really, more info of your application, with pictures could be a great help. As I've asked many times on this forum, "why is it so had to get full information from thread starters?"

A serious lack of reading comprehension all around...
I am fully aware of what is required to make a power supply from a transformer. I even stated this in a previous post that you obviously didn't read.
The assumptions bring made here are that I asked how to do something. Clearly aside from a dynamotor, which is really still just a transformer, there is no other way to get isolated low voltage from mains than using a transformer.
I'm not going to break apart a wall wart to reuse it's circuitry. If you like to do that, hats off.
Like I said the transformer is already in my cart.
I can't get over the attitude here, unreal. The beleif that there has been answers provided, to a question that wasn't even asked.
Rather than answer the question, everyone has decided that I didn't ask that question and instead create answers to the question you think I really wanted to ask.

 

A serious lack of reading comprehension all around...
I am fully aware of what is required to make a power supply from a transformer. I even stated this in a previous post that you obviously didn't read.
The assumptions bring made here are that I asked how to do something. Clearly aside from a dynamotor, which is really still just a transformer, there is no other way to get isolated low voltage from mains than using a transformer.
I'm not going to break apart a wall wart to reuse it's circuitry. If you like to do that, hats off.
Like I said the transformer is already in my cart.
I can't get over the attitude here, unreal. The beleif that there has been answers provided, to a question that wasn't even asked.
Rather than answer the question, everyone has decided that I didn't ask that question and instead create answers to the question you think I really wanted to ask.

Again a lot of smart people on this forum with what you claim is a comprehension problem. I think the problem is elsewhere. You came to us with questions that you don't know the answers. If everyone is so dumb then where does that put you?

 

I think it is clear that you want to build the assembly from the ground up and not appear to be hackish by incorporating a ready-made power supply. That is your choice.

Those commenting are suggesting that a wall wart is a very practical solution, and for some it would be the right one.

I think it is becoming clear that to obtain the kind of isolation and safety that you desire a transformer or a switching power supply incorporating a transformer is the only practical solution. If you do not have room for a transformer and cannot use a pre-manufactured miniature power supply the only solution remaining for a power supply is for you to make your own switching power supply.

This document describes a switching power supply that you can build.
https://ac-dc.power.com/sites/default/files/PDFFiles/der267.pdf?download=1

Be sure to research design requirements for switching transformers meant to isolate the user from the power line. You can buy such a transformer if you understand the specifications.
https://www.digikey.com/products/en...1&nstock=1&quantity=0&ptm=0&fid=0&pageSize=25
https://www.digikey.com/products/en...1&nstock=1&quantity=0&ptm=0&fid=0&pageSize=25

 

An unhelpful post has been deleted.

Further unhelpful posts may be deleted as well.

 

Then use a small PS that has a power cord, and cut off the plug and connect it to the equipment supply terminals.

Better yet, get an extension cord and cut off the plug end. Wire in the outlet part and plug a wall wart into it. I would use some double-stick foam tape to hold the wall wrt in place.

 

Again a lot of smart people on this forum with what you claim is a comprehension problem. I think the problem is elsewhere. You came to us with questions that you don't know the answers. If everyone is so dumb then where does that put you?

Smart people are fully capable of failing to actually read. Which appears to be what is happening here. I appreciate anyone who made an effort to discuss on topic, I do not appreciate people arrogantly answering a question I did not ask, then claiming I'm ignorant to the answers provided.
Mods could you close this thread?

 

impractical in this situation.
Ironically the transformer i'm looking at is $6.50.

What i'm trying to do is add a microcontroller to an existing piece of 120vAC equipment. There is room for a transformer, but its not practical to plug in a wall wart, when the equipment has its own power source, I want the MCU to use the same power source.

This is a vote for transformer no?

I don't see how that would be impractical. You simply purchase an outlet box, and an outlet from any hardware store, wire it in to the 120VAC, and voila- you can now plug your walwart in.

 

I don't see how that would be impractical. You simply purchase an outlet box, and an outlet from any hardware store, wire it in to the 120VAC, and voila- you can now plug your walwart in.

There is some room inside the equipment I am working with, but not to install an outlet box, outlet, and a wall wart.
Why is everyone so hung up on figuring out how many different ways I can use a wall wart?!

TL;DR, - Wall wart is an ugly, impractical solution. I will not use. Original question was asking if there are other ways beyond using a transformer to safely isolate mains from a low voltage circuit. The answer is no. Thread over.

 

As one who suggested a Wall Wart but stripped version, I have done this for both the SMPS and the older linear transformer type to incorporate it into a single unit project.
It is relatively easy to take apart if one get creative.
The complete circuit is removed discarding the AC input pins.
Max.

 

There is some room inside the equipment I am working with, but not to install an outlet box, outlet, and a wall wart.
Why is everyone so hung up on figuring out how many different ways I can use a wall wart?!

TL;DR, - Wall wart is an ugly, impractical solution. I will not use. Original question was asking if there are other ways beyond using a transformer to safely isolate mains from a low voltage circuit. The answer is no. Thread over.

The never ending stream of alternate answers is coming because you keep implying that the required transformer has to be bought all by itself and built around. While that is one possible solution, it's not the only, nor the best, solution.

The transformer can be in a pre made power supply (most likely a SMPS.) The advantages of buying a pre made supply, rather than rolling your own, are:

• Lower cost
• Greater efficiency
• Probably lower ripple and better regulation, unless you put a lot of work and even more money into your home-spun design.

The pre made supply doesn't have to be from a wall wart - that's just the cheapest, easiest way. Other pre made supplies will still probably be cheaper and easier than your proposed solution. (I linked a variety of them at Digikey in my earlier post, and you can definitely get similar parts for much less from other suppliers.)

You're right that your question has been answered many times over, but what people are trying to address is your implication that the answer to the question leads to only one possible solution, which isn't true.