Detect presence of Mains voltage simple and cheaply

Thread Starter

Mreeves

Joined Feb 27, 2021
13
It should work fine either way, you just may need a few more turns of wire if it has the resistor.
Ok thanks I went ahead and purchase 2 I also bought a bunch of transistors and resistors to build an AC detect circuit as a plan B. I really appreciate all the help. I was struggling a bit with how to go about it. If they would have built a status light into the 200 amp breaker to let you know if voltage is present this could have all been avoided ... lol just ranting. I am still a little surprised that I could not find anything on the internet dealing with this.
 

Thread Starter

Mreeves

Joined Feb 27, 2021
13
So I got my Amazon delivery or at least part of it and luckily it was the neon lamps I referenced earlier. I couldn't resist so I gave it a try. I was able to test out the proof of concept. Took some trial and error. I started and wrapped about 18 inches of 14awg wire which was actually 1 conductor of some romex scraps I had. As ya''ll will probably guess this did not work. I found about a 4ft piece of ethernet cable with no ends so I thought I would give it a go. first 4ft or so of a single conductor did nothing. so I added 4 more still nothing. I didn't really get anything until about 16ft. I added 4 more and it got marginally brighter. I will attach a proof of concept. I removed it for now while I think about how I want to go about. the pieces were crudely spliced so a solid piece may have better result but I doubt it. I wasn't sure if I could could overlap it as fear I will run out of room before I get it bright enough for my liking. I know these came with resistors built in. I may try to remove it or look for another that does not have a resistor. does the wire I am wrapping need to be bare? I think I have some cat6 which might be thicker wire. Not sure the best way to go about this. but I would still consider this a success so far. Can I use a manufactured toroidal coil to get better results? If i turned the light off you can see it lit up just slightly. With my garage lights on it was hardly noticeable. IMG-4464.jpgIMG-4462.jpg
 

crutschow

Joined Mar 14, 2008
34,464
The signal is capacitively coupled so a magnetic toroid would not help.

You don't need any insulation under the wrapped wire, since there is already adequate insulation around the main's wire.

Uninsulated, but varnished (magnet) wire would likely give slightly better coupling.
 

Thread Starter

Mreeves

Joined Feb 27, 2021
13
The signal is capacitively coupled so a magnetic toroid would not help.

You don't need any insulation under the wrapped wire, since there is already adequate insulation around the main's wire.

Uninsulated, but varnished (magnet) wire would likely give slightly better coupling.
Something like this Wire?

Mark
 
Last edited:

kennybobby

Joined Mar 22, 2019
75
i'm thinking that in order to capture energy from the electric field, then the plane of the coil needs to be perpedicular to the axis of the mains wire to detect when voltage is present.

Wrapping wire about the mains is creating somewhat of a current-sensing transformer it seems.

E and H Fields.jpg
 

schmitt trigger

Joined Jul 12, 2010
905
I bought a pulsar 12kw peak duel fuel gen for $800.
Is that the Pulsar model PG12000B ?
You got a real deal. Right now they are retailing for $1300.
Laws of supply and demand!

May have to wait for a while, but before the hurricane season begins here in coastal Texas.
BTW, I have performed the neon bulb trick. It works if it is wrapped in a single conductor. If it is wrapped around both the phase and neutral wires, it does not work. Most likely because the fields cancel each other.
The question from here is how to send that information remotely.
 
Last edited:
Top