Transformer basics...

Thread Starter

Externet

Joined Nov 29, 2005
2,202
Hi.
An inductor1 with air core has 1KHz 1Watt applied.

An inductor2 with air core a metre away picks/senses/receives the EM field, and produces -say 1mV-.

If inductor1 gets an iron core instead, will the signal picked by inductor2 be stronger ?

If inductor2 also gets an iron core instead, will the signal picked be even stronger ?
 

#12

Joined Nov 30, 2010
18,224
1Watt applied.
I have some problems with the part about watts. I think it must be an imaginary watt, as in "square root of negative 1" imaginary numbers. The other scenario would be to transmit a real watt, but transmitting a watt at 1KHz is going to require quite a large coil. A half-wave dipole at that frequency is about 1500 kilometers. :eek:

However, the question was answered well enough by disregarding the strange conditions. The concept of magnetic coupling is true. I just don't want you thinking you can actually do that at 1KHz.:D
 

AlbertHall

Joined Jun 4, 2014
12,345
I have some doubts about the 'yes,yes' if it is a solid iron core at 1kHz as the eddy current losses may be greater than the gain from having the core.
Any thoughts?
 

Bernard

Joined Aug 7, 2008
5,784
Maybe the air core wins or why do metal detectors use air cores, & slightly off topic; In 1961 I buried a coil under edge of driveway and another under car runningboard. Car coil was, on demand, fed with a dirty signal from a relay oscillator & buried coil detected noise with a gas triode tube, triggering relay flip-flop opening garage door. Spacing of coils about 18 in.
 

Dodgydave

Joined Jun 22, 2012
11,285
Metal detectors are using the metal to alter the inductance of the air coil....thus changing its frequency...


Thats why AM radios have a ferrite rod antenna.
 
Top