Sensor Design

[Andrew Pike]

I have been looking at using a large toroid for a sensor to tow behind a boat.

What I was thinking of doing was to use 2 or 3 smaller sensors. Would that work? Also would I wire the sensors in series or in parallel?

Thanks

[Willy Bayot]

Re: Sensor Design

If you intend to tow the sensor behind a boat, where would you put the sensor? On an other (plastic) boat? or under the water in a water-tight enclosure (a 'fish')?
On a boat, you should not be too much concerned about the weight and the power consumption of you sensor since you do not have to carry the whole lot on your back.
Thus, you could directly make a 'big', 'heavy', 'power hungry' sensor without any problem.
Now, to avoid the problems of changing earth magnetic field over time, you probably would better build a gradiometer configuration with two sensors separated by one meter or so and two separate amplification channels.

If you want to make a differential mag. (like the one of Phil Barnes) then indeed, you have to combine the two sensors on the same channel and put them in parallel with winding in reverse directions so that their signals mix together to generate the beat frequency.

If you just want to combine several sensors to get a better (higher) combined signal, I guess that you must put them in series and put them VERY close to each other otherwise they will not 'see' the same field strength and they would generate different frequencies. This is an idea that I have not personally tried and I have some doubts about it. I do not know whether the noises will also be added.
If I were you, I would make a 'big' one rather than several small ones.

By the way, we have designed our own amplifier, filter and comparator circuits for our so-called 'MAGPIC01' based on the description of James Koehler , we have routed the circuit using Eagle and we are now waiting for the PCB to be made.
More to come later about our preliminary tests.

Willy

[Willy Bayot]

Re: Sensor Design

By the way, what country are you from?

Willy

[Andrew]

Re: Sensor Design

I'm in the Bahamas.

I am not going to use a differencial or a gradiometer. I am just thinking about fish design, and it is easier to place 3 smaller toroids in a PVC pipe, that use a huge pipe or similar to create a fish for a large coil.

[Willy Bayot]

Re: Sensor Design

Now, I understand your purpose.
You could try to put two or three smaller sensors in series close to each other but I would advise you to carefully test the resulting amplified signal on the ground to see what shape it is and what noise level it contains before you integrate them into a fish.
Good luck,
Willy

[Phil Barnes]

Re: Sensor Design

Why are 3 sensors better than One ?????????

[John oldham]

Re: Sensor Design

Andrew;
You could use 3 to 5 single coils in series and in phase with each coil stacked on top of each other in continous phase rotation. eg.0-120-240 or 0-72-148-276-288 degrees. This is a standand "Geometric" proton coil design. Instead of the difficult
to manufacture toriod coil.
e-mail me for a picture.

john (Ottawa Canada)

[Unregistered]

sensor desung

Dear Willy,

Greetings in the name of the lord. I am very much interested to join this furom on how to deal with sensor designing. I am so wondering how this thinks works? Is sensor made to detect something on the ground or both sea and land? Please send me a complete construction design of sensor and how to position this in connecting to the magnetometer unit. I want both water and land base sensor/magnetometer. Especially the PCB design or layout for magnetometer. I read a lot about construction of magnetometer but it seems no one tell that unit is for land base or water magnetometer.

Here in the Philippines...I am not capable to buy that stuff. I have no such experience in electronics but still seeking to find a Yama****a treasure. For sure, if I can have all the detailed construction of sensor and magnetometer I think I can pursue my ambitious treasure seeking.

Last question: Sir, willy how to connect the sensor to the unit(magnetometer)? If you can send to my email please include drawing illustration on how to connect and position of the sensor or to point it during detection activities?

More power and God Bless You!

Joval

My email add: ([email protected]

[treasurediver]

Would this toroid serve? 2000 turns, #20 wire
treasurediver

[Willy Bayot]

Hi Joval,

To get more details about PPM, have a look at: http://perso.infonie.be/j.g.delannoy...Guidelines.htm

Good Luck,
Willy

Dear Willy,

Greetings in the name of the lord. I am very much interested to join this furom on how to deal with sensor designing. I am so wondering how this thinks works? Is sensor made to detect something on the ground or both sea and land? Please send me a complete construction design of sensor and how to position this in connecting to the magnetometer unit. I want both water and land base sensor/magnetometer. Especially the PCB design or layout for magnetometer. I read a lot about construction of magnetometer but it seems no one tell that unit is for land base or water magnetometer.

Here in the Philippines...I am not capable to buy that stuff. I have no such experience in electronics but still seeking to find a Yama****a treasure. For sure, if I can have all the detailed construction of sensor and magnetometer I think I can pursue my ambitious treasure seeking.

Last question: Sir, willy how to connect the sensor to the unit(magnetometer)? If you can send to my email please include drawing illustration on how to connect and position of the sensor or to point it during detection activities?

More power and God Bless You!

Joval

My email add: ([email protected]

[sajjad]

types of sensors

hi sir

first of all i am working on carl Moreland gradiometer.
I question is that how many types of sensors are there in the field of magnetometer? and what are the specific advantage of one on others sensors.
mainly the fluxgate and ppm sensors?
please enlist all tpes of sensors and theier specifications.

thanks alot sir
Sajjad

Hi Joval,

To get more details about PPM, have a look at: http://perso.infonie.be/j.g.delannoy...Guidelines.htm

Good Luck,
Willy