Discussion in 'Electronic Design' started by Brent, Apr 4, 2004.

1. ### BrentGuest

I am trying to design AC magnetic field detector, to detect a signal of
75KHz from a wire loop. For a maximum efficiency I need to know how to
design the coil for its resonance. I have the formula (Faraday's Law on
Induction?),
fo=29.85(h/d)1/5 divided by nd. My question is how to associate the
variables of the formula. How many turns wire do I make, what diameter &
what height. Also do I need a ferrite core, or a nonmagnetic core. Should
I incorporate a capacitor into my circuit, but what size?

Any help would be appreciated,
Brent

2. ### ddwyerGuest

If a single frequency then resonate the coil with a capacitor.
If broad band then terminate the coil in an a voltage amplifier..
I didithis latter years ago to measure magnetic fields from power lines
and electric cooker etc.

3. ### BrentGuest

How do I calculate the size of capacitor that I need?

Thanks,
Brent

4. ### Rene TschaggelarGuest

the resonance frequency is omega=1/sqrt(L*C)
A few tries are usually much simpler, as
calculating the selfinductance of your coil is
not trivial.

Rene  