How does a filter inductor smooth current in a rectifier circuit?

Thread Starter

Amped_86

Joined Jun 28, 2018
20
Copy of single phase bridge inductor filter-schematic.pngI have a rectifier circuit that I came across in my textbook. I'm concerned with only one specific part of the circuit at the moment. After the source voltage is rectified and arrives at the inductor, what actually smooths out the current? I know that the inductor opposes changes in current and initially the current is rising (along with a changing magnetic field). So when the rising/changing current approaches the inductor a magnetic field is induced in the inductor that opposes the the magnetic field of the current. A voltage/EMF is also induced in the inductor that opposes the change in current. As soon as the current reaches its peak and begins to decrease, The magnetic field/Voltage/EMF induced in the inductor is reversed and the inductor tries to aid the now decreasing current. But how has this processed smoothed out the current? Is it the EMF that reacts against the current initially pushing against it and then pushing with the current that causes it to smooth out?
 

Veracohr

Joined Jan 3, 2011
721
Is it the EMF that reacts against the current initially pushing against it and then pushing with the current that causes it to smooth out?
It doesn't work "against the current" then "with the current", it works against the change in current. Whether that change is increasing or decreasing. Just a clarification on wording, but maybe that's what you meant anyway.
 

upand_at_them

Joined May 15, 2010
474
the inductor tries to aid the now decreasing current
I've seen this wording before, but always seems odd. The inductor never "tries" to do anything. The reason current continues is that the magnetic field of the inductor starts to collapse and it is the collapsing field that induces current in the wire. Remember, current is induced in a wire by either a) moving the wire or b) moving the magnetic field. The "filtering" happens because the inductor's magnetic field keeps "filling in the gaps". Above flywheel analogy is good. Think momentum.
 

sparky 1

Joined Nov 3, 2018
301
A practical application can be solved. By doing the math the question logically becomes:
What effect does this arrangement have and how much ? It is what it is. A physics class sets up a
whole different demonstration on why. That is the nature of your question.
snubber.JPG
 

dendad

Joined Feb 20, 2016
3,595
It’s only good if you know something about flywheels and engines. Not everyone does.
An easy way to find out, with nothing in your hand, hold your arm straight out and rappidly wave your arm about.
Then, hold a brick in your hand and again wave your arm about.
Very similar to a flywheel.
 
Top