Discrimination + VDI THEORY

[Davor]

I think it is called rototrol. For 2 quadrant solution it could be achieved by two crossed dials as well. Unfortunately nowadays such instruments are incredibly expensive.

As soon as I fix the sound modulator thing I'll make some attempt to make this phase thing. Unlike rototrol solution, I can mirror the reverse phases and make them meaningful. It will make sound mapping straightforward and continuous for a wild dynamic range and all 4 quadrants.

[aothunterpl]

Hi I have a question

Referring to the book (Inside The Metal Detector), pattern Eq-7-4, Eq 7-5

+ this is what was previously written on the forum to calculate the phase shift we need function arctan (y / x)

for example: arctg(60mV/-95mV) = (-32.27 ^) the result in the book is in degrees

Now fi (phase) = -32.27^ [+ 90^] = ~ 58^ degrees


Is not it should be added that the function arctan first result is calculated in radians, then we need to convert the result to degrees. (as in most of the features built into the C compilers - so I guess it seems)


arctg(60/-95) = -0.562902 rad

-0.562902 * (180 / PI) = -32.27^ degrees


thanks for the explanation

[Qiaozhi]

Hi I have a question

Referring to the book (Inside The Metal Detector), pattern Eq-7-4, Eq 7-5

+ this is what was previously written on the forum to calculate the phase shift we need function arctan (y / x)

for example: arctg(60mV/-95mV) = (-32.27 ^) the result in the book is in degrees

Now fi (phase) = -32.27^ [+ 90^] = ~ 58^ degrees


Is not it should be added that the function arctan first result is calculated in radians, then we need to convert the result to degrees. (as in most of the features built into the C compilers - so I guess it seems)


arctg(60/-95) = -0.562902 rad

-0.562902 * (180 / PI) = -32.27^ degrees


thanks for the explanation

Of course, whether the result of the arctan calculation is in radians or degrees depends on the function being used. If you have a scientific calculator, you can change the mode to either degrees or radians. When using a PIC, however, the result is normally in radians, which can easily be converted to degrees by multiplying by 57.3 (which is the same as 180/pi).

I've made a note to add this information to a future revised version of ITMD.
Thanks.

[aothunterpl]

Welcome

Below shows my test program VDI + Tesoro Eldorado

Atmega 16 processor

in algorytm I used the built-in arctangens >>> atan2 (Y, X).

Not gonna use the table of values


http://www.youtube.com/watch?v=7GBz1...ature=youtu.be

[aothunterpl]

Hi I had a request for a final explanation of some demand.

Because the literature on the detectors is printed several terms that are mutually mixed and probably depend on each other.


It is known that the signal X and Y (R) are mutually equivalent, constitute a single signal that will probably delay the incoming signal. This translates into a phase shift.

I understand that these two factors affect the displacement vector in the magnetic field - inducted in a metallic object.

In turn, these magnetic field (or energy) balance stab a transmitter - receiver causing idnducted signal in the receiving coil.

The signal will be inducted phase shift (delay) the signal transmitter.


Now in literature was met with such properties are assigned in channel X and Y (R):

-------------------------------------------------- ----------------------------------------

- "The phase shift depends on the magnetic and electrical properties of metal"

- Redistribution, Absorption (strengthening and weakening of the magnetic field) depend on the magnetic permeability and electrical conductivity

- Phase depends on the conductivity



Channel X is related to:

a) Magnetic factor (Conductivity)
b) factor (reactance)
c) magnetic permeability (micro u0)


Y (R) is related to:

factor electrical resistance (resistivity)


The detector distinguishes metals by the ratio of algebraic signals Y (R) / X


this happens

- Magnetic induction (electromagnetic)
- Magnetic permeability "u"


Can I ask you a few sentences explaining exactly what goes for X and Y and the factors are interrelated

Because literature written by both the X refers to the conductivity and often write that Reactance, magnetic u (micro)


Thanks in advance greetings