FGM-3 SENSORS NEEDED

[moon112233]

does anyone have any speake FGM-3 magnometer sensors they no longer need and want to sell....


moon.njd@gmail.com

[moon112233]

anyone ????

[sinclairuser]

since speake died and the company went out of buisness this link is the only place with alternatives.

https://www.fgsensors.com

hope that helps,
aly.

[ivconic]

In 3 orders i bought serious batch from this guy:

https://www.tutti.ch/vi/26183389.htm

Because i prepare decent number of my devices for exporting abroad.
So i had to be sure about sensors in advance.
My experiences with these sensors are quite alright.

[ivconic]

Of curse i also had chance to obtain sensors from https://www.fgsensors.com/ too.
Quite alight too. No complains,
Both, from previous link and this link here; works quite alright, within the proper ranges.
So, luckily to us all; we can still obtain fluxgate sensors of that type for our works.
The price range and differences are insignificant.

[sinclairuser]

thanks ivconic, i did notice that the FG-3 sensors were missing the 4th pin(feedback i think), looking at your first link the ones from the tutti link do have the feedback pin i dont know if that matters for our simple mag designs or your more complex ones but at least both types are available.
luckily i got a couple of speake units ages ago with the other bits needed to build Carls flux mag.
but like a lot of projects, i bagged all the parts and put it to one side, i tend to just do one project at a time these days so when i get to that project i will build it.

[ivconic]

thanks ivconic, i did notice that the FG-3 sensors were missing the 4th pin(feedback i think), looking at your first link the ones from the tutti link do have the feedback pin i dont know if that matters for our simple mag designs or your more complex ones but at least both types are available.
luckily i got a couple of speake units ages ago with the other bits needed to build Carls flux mag.
but like a lot of projects, i bagged all the parts and put it to one side, i tend to just do one project at a time these days so when i get to that project i will build it.

Our colleague Simon is here, member of the forum.
He can disclose details about missing f/b pin, since it is his production.
I guess he finds it redundant, which is alright in most of the cases and applications.
f/b pin can be used to slightly improve linearity, by adding negative voltage and small current on it (explained in Speake papers).
Another and probably better method to improve linearity is to add extra winding, a coil, over the sensor (also explained in some papers).
I guess Simon omitted f/b exactly for that reasons.
On "tutti" link however the "H" version of sensor is having f/b pin. But i never even give it a try so far.
In the application that i use here; linearity is of secondary interest. Not that i wouldn't like to improve it, but by now is out of my focus.
So... if you want to use f/b pin; than you can obtain the "H" version, otherwise Simon's sensors will do the job just fine.
"H" version is with narrowed range. That's the only difference.
Again it is of secondary interest for me, because i deal with that in code. I can manipulate in code with signal anyway i want.
I never managed to obtain some chips, to be able to make Carl's version. So i never made it.
But i had read the article many times so far. In essence that's it. Interesting design, no doubts about that.