Coil Field Examiner

[codan]

Hi everybody,

I am new to electronics & am in need of some help, i want to test the magnetic field strength of some coils--metal detector coils in particular.

I have a PC based oscilliscope, voltmeter, function generator that i can use to gather some data.

My first question is:
Is there any difference between AC & DC magnetic field detection apparatus or is it basically all the same?

I need an easy to make electronic circuit that i can connect to my PC to collect some data.

I have found a Circuit that i have attached & was wondering if instead of using the needle type gauge if i can connect onto this to read from my PC based voltmeter. Or if in fact this circuit will do the job.
Or is there a simpler more effective way to do this.
Someone told me to use just a large coil of wire with a capacitor across the two wires but i am unsure what there talking about or how to set it up.

I don't know all the electronics talk so please take it easy with the replies

Thanks

 

[JimB]

Is there any difference between AC & DC magnetic field detection apparatus or is it basically all the same?

Depending on what you are trying to do, the techniques will be different.

I have found a Circuit that i have attached & was wondering if instead of using the needle type gauge if i can connect onto this to read from my PC based voltmeter.

There is no obvious reason why you could not use the PC voltmeter instead of the analogue meter in the circuit.

Or if in fact this circuit will do the job.

A very good question!
There are one or two things about that circuit (as you have drawn it) which look a bit "iffy", especially the circuit around the meter.
It looks all wrong.

Or is there a simpler more effective way to do this.

Very likely.
What are you really trying to measure and why?
This sounds like one of those situations where we should be looking at the basic problem to find a good solution, rather rather than trying to implement what may be the wrong solution.

JimB

 

[codan]

Thanks JimB,

Your reply is well understood.

As a project to learn more about metal detectors & the way they work i am in the process of collecting information & putting together a couple of metal detector circuits of different types eg BFO, VLF & PI.

I want to make changes to the circuits & experiment with things a little, to do this & to understand more about the effects of the changes i must be able to get some data on things like field strength, pulse timing etc.
Also to be able to test various coil designs for field strength.

Without being able to actually test & verify everything it will all be guesswork & unreliable results will be obtained. I find it imperative to be able to test & obtain accurate results & is the only way of knowing for sure if changes made are actually beneficial or a waste of time.

I would like to get the testing side of things done first before i venture any further with the project--to me this is the most important thing.
Not much good building things first up if you can't test them with some accuracy.

Hence the need for a circuit to be able to detect the field strength etc & to get it to my PC.

I find all this very interesting & any helpful solutions would be appreciated greatly, as long as you don't mind all my novice questions.

Thanks