A way to detect a power outage at home

Projects General Guidance
1

Hi,
I was thinking how can we make something that can detect a power outage in a room or home without it being connected on the wall.

Imagine a battery powered Arduino (if you have one) and then place it on the middle of your kitchen table.
What modules or sensors could you use to detect a power outage?

A light sensor or LDR would not distinguish night time or turning off a light between a power outage.

Also, not by making a transmitter plugged to the wall and when there is no power trigger the power outage alarm.

How about a wifi module that checks for the modems signal? But, yet again, some wifi boxes have a backup battery.
[Addendum #1]
I was thinking more about the Wifi boxes that have a battery backup.
Is there a website that tells you what areas or streets have a power outage? Because that would solve everything. If the Wifi disappears, most likely there was a power outage if the cat had anything to do with it. But it the Wifi box has a battery backup, then connect to that website and see if the street your in has had a power outage. Ding!?
[/#1]

Any ideas? Thanks! :slight_smile:

2

Remove the walls, and what do you see.

A birdcage of power wires around us.

A coil, followed by a narrow band mains frequency opamp could detect if there is mains hummmmm or not.

I guess you will have to design and build that amp yourself.
Leo..

3

Is this assuming the Arduino is not receiving it's power from the same source? Guess it would have to be powered by an isolated supply. An LDR (in the form of an opto-isolator) would work. A relay, the coil of same being powered by mains. - Scotty

4

scottyjr:
Is this assuming the Arduino is not receiving it's power from the same source? Guess it would have to be powered by an isolated supply. An LDR (in the form of an opto-isolator) would work. A relay, the coil of same being powered by mains. - Scotty

It would be a battery powered Arduino nowhere near a plug :frowning:

5

Wawa:
Remove the walls, and what do you see.

A birdcage of power wires around us.

A coil, followed by a narrow band mains frequency opamp could detect if there is mains hummmmm or not.

I guess you will have to design and build that amp yourself.
Leo..

ok. thx.

6

Pringles:
It would be a battery powered Arduino nowhere near a plug :frowning:

That is why they make extension cords. You need to be specific as to the requirements and conditions for much help.

7

How about an arduino powered by mains with simple 433 MHz Tx, battery powered unit with simple Rx.
Tx can send continuous message, Rx can wake up every once in a while (to extend battery life) & listen.
No message, infer the Tx power is out.

8

What do you mean by a power outage.
Do you mean the power is off for a long time , or a short loss in power, ie for a second or so.
Are brownouts also included.
ie whats the purpose of the project?

9

What is the Arduino expected to do when it detects that the power has failed ?

If the Arduino is battery powered, how long do you expect the battery to last?

If mains power is available why not run the Arduino off a battery that is being trickle-charged by the mains. The Arduino can detect the low voltage charge input to the battery. If the charge voltage fails it means the power has failed but the Arduino will continue running on battery power for some time.

...R

10

Ok, I appreciate all the answers and questions. Allow me elaborate more.

Have you ever seen those emergency lights on buildings or schools? The ones that have two light bulbs, or nowadays LED’s on the sides and int the middle they have a battery cover?
Well, What I’m trying to do is that, an Arduino that detects a power outage and turns on the light so people can see and exit the building. Why not just buy one of these or plug the Arduino to the wall and go from there you ask?
What I’m trying to do here is to have the Arduino completely isolated, physically, no opto-isolators no cables, no external or additional components/sensors. Think about it as a portable unit that you can bring to other places. What does most people have on their home? Wifi.
For instance, suppose that the unit will read all the available Wifi signals and grab the strongest assuming that’s the home where the unit is in. If that Wifi signal goes down, trigger the LED. This is assuming that the unit was correct in selecting the strongest Wifi correctly and that the Wifi box did not had a battery backup. I propose this idea but I don’t know if it is reliable although it might be the only one that requires external parts.

The Arduino will be battery powered, batteries will last a long time, don’t worry about that. Size don’t matter within reasonable reason. xD

I’m asking if is possible and if so, how? Am I dreaming too big? This is all hypothetical, so, chillax.

Robin2:
What is the Arduino expected to do when it detects that the power has failed ?
If the Arduino is battery powered, how long do you expect the battery to last?
If mains power is available why not run the Arduino off a battery that is being trickle-charged by the mains. The Arduino can detect the low voltage charge input to the battery. If the charge voltage fails it means the power has failed but the Arduino will continue running on battery power for some time.
...R

Light a LED. Let’s say the Arduino will last a year on batteries, but that’s not an issue for know. The point is to not have it connected to mains power.

zoomkat:
That is why they make extension cords. You need to be specific as to the requirements and conditions for much help.

I forgot to mention that, I’ll try to explain better.

CrossRoads:
How about an arduino powered by mains with simple 433 MHz Tx, battery powered unit with simple Rx.
Tx can send continuous message, Rx can wake up every once in a while (to extend battery life) & listen.
No message, infer the Tx power is out.

That’d be great, but that would require another external thing. Thanks!

mauried:
What do you mean by a power outage.
Do you mean the power is off for a long time , or a short loss in power, ie for a second or so.
Are brownouts also included.
ie whats the purpose of the project?

What I mean is, when the power at your home goes down the Arduino activates. Not at the millisecond level but, it would be OK if it works within 5 seconds, no more than 10 seconds after the power is down. Purpose, emergency, portable, and the challenge to me and all of you. Also, curiosity of mine, if it’s possible to do etc....

Thank you all!

11

Hi,
What is keeping the emergency lights battery charged?
Circuit monitors charger input, no charge means no power switch on emergency lights.
That's how they work.

No need for a portable mains sensor.

Why complicate things?

Tom..... :slight_smile:

12

Pringles:
What I’m trying to do here is to have the Arduino completely isolated, physically, no opto-isolators no cables, no external or additional components/sensors. Think about it as a portable unit that you can bring to other places.

I can understand the concept of it being portable.

But, if you are telling us the whole story, by definition there will be power available wherever it is deployed. And it would be a very unusual location that would not have an electrical socket to which either the unit or a sensor could be connected.

To my mind the concept of using WiFi or equivalent as an indicator assumes more complexity on the part of the local system than simply connecting to an electrical socket.

I do wonder if we are hearing the whole story. Perhaps the OP is trying to detect something else entirely.

...R

13

TomGeorge:
Hi,
What is keeping the emergency lights battery charged?
Circuit monitors charger input, no charge means no power switch on emergency lights.
That's how they work.

No need for a portable mains sensor.

Why complicate things?

Tom..... :slight_smile:

Batteries will last a long time on sleep mode, a red led will light up when a new battery is needed.
Why complicate things? Where is the challenge on that I say :stuck_out_tongue:
I’m not trying to complicate anything, is just a taught I had and I’d like to know if it is possible as I’m asking. No wall chargers etc.

14

Robin2:
I can understand the concept of it being portable.

But, if you are telling us the whole story, by definition there will be power available wherever it is deployed. And it would be a very unusual location that would not have an electrical socket to which either the unit or a sensor could be connected.

To my mind the concept of using WiFi or equivalent as an indicator assumes more complexity on the part of the local system than simply connecting to an electrical socket.

I do wonder if we are hearing the whole story. Perhaps the OP is trying to detect something else entirely.

...R

Thanks!
The whole story? I could elaborate way more but as you can see, I mention battery power and now, about 35%ish of this is about how will I charge the batteries or know if they have power.
Anyways, I say this will seat on a kitchen table perhaps. It will look like a nice decorative thing in the center of a table with the use of lightning the room in case of no power.

What else could I detect with the power outage detection (however that might be(if possible)) capability?

15

what you are talking about is a radiation detector to see of there are bands of force in close proximity.

there are plenty of voltage detectors that are non-contact. they are tuned to be next to or very near to the wires.

if you live next to power lines, you can go out and stand a fluorescent lamp into the ground with the end up in the air and get it to glow. add more of an antenna and it will glow more.

16

What about something like a PIR to detect if there is a person in the room and then turn on the emergency light if it is dark ?

On the assumption that a person would not be in a dark room if the mains power was working.

...R

17

Robin2:
What about something like a PIR to detect if there is a person in the room and then turn on the emergency light if it is dark ?

Like the ones you buy?

18

dave-in-nj:
what you are talking about is a radiation detector to see of there are bands of force in close proximity.

there are plenty of voltage detectors that are non-contact. they are tuned to be next to or very near to the wires.

https://www.youtube.com/watch?v=ZUw79RJMj-g

Wow, I really liked the Sperry one, the most sensitive he showed. Could this be higher of sensitivity so that it works further away from the cable/wall? How can I look more into this? Looks interesting! Thanks a lot!
non-contact voltage detectors/arduino

19

Robin2:
What about something like a PIR to detect if there is a person in the room and then turn on the emergency light if it is dark ?

On the assumption that a person would not be in a dark room if the mains power was working.

...R

Hmm, good idea, combining sensors. If I owned pets, it would be a nightmare, don't get me wrong, I love pets.

I like it! Thanks! :slight_smile:

20

I've emergency lighting in my home. It's just a car battery charger, a car battery, a 12V relay and a 20A power diode.
It's wired so that, if the mains fails, the battery charger stops powering the relay coil, the relay drops out and the battery powers up some 12V lights. The diode is needed to prevent the battery powering the relay coil. The battery is on trickle charge 24/7. I've added a push to break button in the 12V line to simulate a power cut and check that it's working, as all the components are hidden in my attic.