How inductors are affected by other factors

1. Jul 29, 2015

Hi all,

A few basic questions regarding inductors really. I'm just doing a bit of reading into these little beauties and trying to get to grips with the workings. My questions are:

1.) Do inductors generate larger magnetic fields with DC or AC? (Providing the same current and voltage)

2.) If the inductor increases in size and turns and the core is made larger, does the current and voltage (DC) also have to be increased to increase the magnetic field? Or if the same voltage and current is applied to a smaller inductor which produces x mm range magnetic field and I increase the size of the inductor, will the magnetic field increase with the same amount of current and voltage (Again DC).

3.) How come inductors don't damage the rest of the circuit board they are situated on with their magnetic field? Like an EMP would if it was turned on near the circuit? Or are EMP's a completely different concept?

Again, sorry if anything sounds basic, new to this magical world of electronics.

Many thanks guys!

2. Jul 29, 2015

Dr. Courtney

3. Jul 29, 2015

Jeff Rosenbury

1) Larger with DC. AC has several different ways of measuring. A voltage can be measured from its positive peak to its negative peak for example. However most of the time it is specified as root mean squared (rms). This is the measurement where AC and DC are the same. So if an AC voltage is 10Vrms, it is ≈14Vpp. It then provides voltage like a 10V DC measurement.

2) For area, the magnet remains just as powerful (less additional wire losses). However the "power" of the magnet is distributed over a greater area, so might seem weaker for small objects.

The strength of the magnet goes up with more turns.

3) The magnetic field outside the windings is pretty dispersed. Even so inductors are often put in metal cans so they don't couple to other circuits.