Just curious. I am about to put this kit together, and wonder if anyone has actually done it. No circuit schematic or explanation came with the kit, and the...
Hi: I don't see the pots you mention at: http://www.fatquarterssoftware.com/downloads/scl007.pdf Where do you see them? I think the IC is a PIC micro...
Hi all (and hal) Mrs Kern (FQS here) - Erich is sick at the moment or he would be answering these question for you. He will be home from the hospital in a week...
Hi all (and hal) Mrs Kern (FQS here) - Erich is sick at the moment or he would be answering these question for you. He will be home from the hospital in a week...
Laurie: I wasn't trying to put any pressure on you or Erich, quite the opposite. Just trying to see if anyone else knew, so any pressure would be OFF you and...
Right, Brooke, Speake just shows the two inputs (presumably different- period square waves) going into their ASIC (which may well be a programmed PIC or other...
Well, one mystery gets solved. The Speake gradiometer datasheet has a phrase in one sentence that notes that the signals from the two sensors are time...
Hi Hal: If the IC is a PIC 16F84A (just a guess based on matching pinouts for power, crystal and I/O pins then the two sensor inputs go to RA0 and RA1. These...
Brooke, that's all quite reasonable. 1. The conjecture that it is a 16F84 or equivalent is reasonable. Both the pinout and the fact that that is the most...
Hi Hal: The 16F84(A) used to the the choice for hobbyist projects, but now it's obsolete. The closest today maybe the 16F88. The data sheet for the SCL-007...
Have just been looking at the X-ray of the FGM sensor - very impressive. Would anyone care to guess-timate the number of turns in those coils ? Colin...
... I think it is very possible. When I studied the x rays, closely, I convinced myself that besides the windings of fine wire, there is a spiral of much...
HI John: I agree, and it's probably Metglas. Have Fun, Brooke Clarke w/Java http://www.PRC68.com w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml ...
... Probably so. it can be made with a nice square BH loop and is pretty insensitive to being bent a little, compared to Permalloy and other nickel alloys. I...
Hi John: You can get more material inside the core by using a spiral than a straight strip. I like the plastic rod idea, seems easier and stronger than the...
So it looks like we're looking at a few hundred turns at the very least .... ... Maybe this is a case for a suck-it-and-see approach ? If you insert a small...
... I have posted a scope capture of the voltage drop across a 1 ohm resistor in series with the 5 volt supply line. When the energize part of the cycle...
Well, Speake may say 20 MHz and that may be the max for the 16F84, but this particular kit has a 16 MHz crystal, marked 16.000 plain as day. Case closed. I did...
hlewislll wrote: (snip) ... Go back through messages in this group related to FGM-3 and you will find lots of discussion about what is inside the unit. The...
OK, I've looked, and find that Brooke raised the question a year and a half ago. Since then there has been a lot of educated guesswork (much of it by you), but...
I have never seen a FGM3, so I am wondering if the output is a square wave or does the duty cycle change with changing fields?? This might give a clue to what ...
I just came across a new patent that resembles a magnetometer design that was posted on this site back in 2005. It is a closed loop AMR type of mag. Does...
... In my photo folder I have scope captures of the output waveform. If the external field changes the positive output part of the wave is most affected in...
Actually I remember it as it was a thin core material wrapped abound a non metallic core in as spiral or helix if you prefer. Do you have a schematic of what...
... I have reconstructed the general form of the schematic from the x rays, and posted it to the group's photo section under my name. Another member also...
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