Help with power supply design for multi purpose outlet

Thread Starter

staylor97

Joined Oct 18, 2018
4
Hi,

I am designing a power outlet that will have various functions such as LEDs along the bottom of the panel and also with USB functionality. need help with circuitry for this project. I do not need to physically build this but only simulate it. any help would be greatly appreciated.


Something similar to the outlets below but only with 3 LEDs on the bottom of the panel.
 

wayneh

Joined Sep 9, 2010
17,152
Hi,

I am designing a power outlet that will have various functions such as LEDs along the bottom of the panel and also with USB functionality. need help with circuitry for this project. I do not need to physically build this but only simulate it. any help would be greatly appreciated.


Something similar to the outlets below but only with 3 LEDs on the bottom of the panel.
What do you want the LEDs to do? If you have USB power available, you can use the 5V to power the LEDs. Or you could use whatever DC input there is to the regulator that controls the USB voltages.
 

MisterBill2

Joined Jan 23, 2018
8,808
I would not choose to ever have a USB connection that close to a mains connection. Just because a lot of them are sold and installed does not make it a good idea. And while wanting to "design" such a system, aside from creating a circuit to provide the voltages there is the more challenging part of creating the actual hardware and having it perform correctly for a long time, many years, without failing or starting a fire or delivering shocks. Creating the actual assembly after creating a valid circuit can be a very big challenge indeed.
 

Thread Starter

staylor97

Joined Oct 18, 2018
4
What do you want the LEDs to do? If you have USB power available, you can use the 5V to power the LEDs. Or you could use whatever DC input there is to the regulator that controls the USB voltages.

I wish to have LEDs along the bottom of the power outlet panel which will be activated by a motion sensor. I am Just not sure how i can go about achieving this. My task is to create a power supply to convert AC to a dual polarity DC voltage output. The DC levels must also be without ripple or noise. Not sure how to do this with these various functionalities such as USB and LEDs
 

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wayneh

Joined Sep 9, 2010
17,152
My task is to create a power supply to convert AC to a dual polarity DC voltage output.
Can you enlighten us as to why this is your task? Who says?

This is one of those projects that, if you have to ask how to do it, you probably shouldn't be doing it. In fact I don't think this thread will be allowed to continue due to safety concerns inherent in this kind of project.
 

Thread Starter

staylor97

Joined Oct 18, 2018
4
Can you enlighten us as to why this is your task? Who says?

This is one of those projects that, if you have to ask how to do it, you probably shouldn't be doing it. In fact I don't think this thread will be allowed to continue due to safety concerns inherent in this kind of project.

Its a project i thought i would start as i am interested in power electronics but realised i am having trouble with it. I will not be physically creating or manufacturing this, i just want to simulate it to show how it would work.
 

wayneh

Joined Sep 9, 2010
17,152
Its a project i thought i would start as i am interested in power electronics but realised i am having trouble with it. I will not be physically creating or manufacturing this, i just want to simulate it to show how it would work.
OK, so if you create a DC supply using a transformer (for isolation from the mains), a full bridge rectifier with filter cap and then a voltage regulator to control at 5VDC, that's OK? I think that kind of design might be impractical inside a real receptacle but if we aren't constrained by reality, it's simple enough. Have you identified a motion detector you want to use?
 

MaxHeadRoom

Joined Jul 18, 2013
23,166
Its a project i thought i would start as i am interested in power electronics but realised i am having trouble with it. I will not be physically creating or manufacturing this, i just want to simulate it to show how it would work.
There is a distinction in the use of a 240vac power outlet with a USB socket, Power Electronics as such would hardly come together in an outlet in this way, so in this instance 'Power & Electronics' are quite separate.
Max.
 

djsfantasi

Joined Apr 11, 2010
7,700
There is a distinction in the use of a 240vac power outlet with a USB socket, Power Electronics as such would hardly come together in an outlet in this way, so in this instance 'Power & Electronics' are quite separate.
Max.
But as others have stated, this design is common. Hardly “would hardly ever come together”

Any US airport has these outlets (admittedly 120VAC). Many restaurants/bars do as well. I had some installed in my old house. New houses come with them.
 

Thread Starter

staylor97

Joined Oct 18, 2018
4
OK, so if you create a DC supply using a transformer (for isolation from the mains), a full bridge rectifier with filter cap and then a voltage regulator to control at 5VDC, that's OK? I think that kind of design might be impractical inside a real receptacle but if we aren't constrained by reality, it's simple enough. Have you identified a motion detector you want to use?

Sorry i meant a light sensor not a motion sensor :)
 
Help us to help you, do you have a spec of what you are 'theoretically building' and it's purpose? As many have already said, the wall socket + 5v USB has been around for ages, it just uses a simple step-down transformer, what new twist are you putting on it with sensors and LED's?
 

MisterBill2

Joined Jan 23, 2018
8,808
The fact is that using a separate adapter plugged into a mains outlet allows a lot more choice in what is located in between the mains and that outlet, AND it also allows one to avoid the constant power spent by the supply when no load is attached.
 
The fact is that using a separate adapter plugged into a mains outlet allows a lot more choice in what is located in between the mains and that outlet, AND it also allows one to avoid the constant power spent by the supply when no load is attached.
Hi Mister Bill, I'm new here and learning so can you clarify what your last post meant
1 "more choice in what is located in between the mains and that outlet" I thought the outlet was already directly connected to the mains THEN you have a cable from the outlet to the appliance.
2 "avoid the constant power spent by the supply when no load is attached" If there is no load how is power being spent, I thought having anything plugged in with no load was like leaving the hose switched on at the tap but blocked at the nozzle e.g. nothing flows.

I'm not being argumentative I just want to get what I'm missing.

Cheers

Lee
 

MisterBill2

Joined Jan 23, 2018
8,808
Hi Mister Bill, I'm new here and learning so can you clarify what your last post meant
1 "more choice in what is located in between the mains and that outlet" I thought the outlet was already directly connected to the mains THEN you have a cable from the outlet to the appliance.
2 "avoid the constant power spent by the supply when no load is attached" If there is no load how is power being spent, I thought having anything plugged in with no load was like leaving the hose switched on at the tap but blocked at the nozzle e.g. nothing flows.

I'm not being argumentative I just want to get what I'm missing.

Cheers

Lee
OK, The item in the discussion is one that in addition to mains power also has a USB outlet for charging things. My point about that is that the quality and condition of that is quite unknown.
And with the second part, any power supply connected to the mains is using some power, even if it is not delivering any power to a load. So it is not at all like a hose, but more like an engine idling. It consumes some energy even when it is doing nothing useful. That is why there has been legislation to improve the efficiency of wall wart power supplies. They burn power as long as they are plugged in. The newer ones are better, but stil they burn some power all the time.
 
OK, The item in the discussion is one that in addition to mains power also has a USB outlet for charging things. My point about that is that the quality and condition of that is quite unknown.
And with the second part, any power supply connected to the mains is using some power, even if it is not delivering any power to a load. So it is not at all like a hose, but more like an engine idling. It consumes some energy even when it is doing nothing useful. That is why there has been legislation to improve the efficiency of wall wart power supplies. They burn power as long as they are plugged in. The newer ones are better, but stil they burn some power all the time.
Thanks for that Bill, I had no idea transformers used juice even when they don't have load, I usually have 4 or 5 plugged in around the place for convenience as I have number of appliances that use micro USB to charge, times that by a few million people and your'e looking at some serious wattage wastage!
 
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