2015-08-28, 06:49
Hello,
I would like to know if any of you have tried to see if variations in the H-field could be detected if you move a magnet in front of a ferrite antenna.
It would probably need to be moved/waved a bit fast because of the low pass filtering in the preamps to see anything.
The reason why I ask is because I want to see if I can make a system to detect magnets being brought into a fitting room.
Shoplifters use strong magnets to take of security labels. If you can detect their magnets, you can catch them in the act.
I already have a system that can detect a magnet at about 30cm, but I want to extend this to about 80-100cm.
The (leaked) pictures of the system blue preamp look a lot like what I had in mind to make, but in my case with low pass filtering and probably a lot of gain.
Milan.
I would like to know if any of you have tried to see if variations in the H-field could be detected if you move a magnet in front of a ferrite antenna.
It would probably need to be moved/waved a bit fast because of the low pass filtering in the preamps to see anything.
The reason why I ask is because I want to see if I can make a system to detect magnets being brought into a fitting room.
Shoplifters use strong magnets to take of security labels. If you can detect their magnets, you can catch them in the act.
I already have a system that can detect a magnet at about 30cm, but I want to extend this to about 80-100cm.
The (leaked) pictures of the system blue preamp look a lot like what I had in mind to make, but in my case with low pass filtering and probably a lot of gain.
Milan.