Inductive Kickback

[forest]

I think we should first concentrate on simple boost converter.
I think, when the inductor is charged from battery it creates cemf against battery emf due to magnetic field expanding. When connection is changed then battery emf passed through the inductor charging capacitor via diode very quickly to the battery voltage and then capacitor is acting like a break in the circuit. Magnetic field of coil collapse and create emf which add to the emf of battery and capacitor voltage is rised to the sum of battery voltage and induced emf of coil.




Is there any current generated when coil field is collapsing or it's just the combined emf's of coil and battery which can charge capacitor to the higher voltage then battery ?
Please explain how you see it operates. Please correct me if I'm wrong.[/size]

[citfta]

Hi forest,

The answer to your question is yes.  Yes there is a current being supplied by the coil field collapse.  Your second part where you ask if it is the combined effect of the coil's emf and the batteries emf is also correct.  Current is just the movement of electrons.  So when the coil field collapses then it induces a voltage (emf) in the coil.  If there is a path for the current to flow then current will flow because of the emf being applied.  As you correctly thought this voltage is added to the voltage of the battery to charge the cap to a higher voltage than the battery voltage.  The higher voltage also means that more current will flow into the cap.  So you see the coil collapse adds voltage and because of the added voltage also adds current.  Here is a nice tutorial all about switching power supplies.  It includes boost, buck and inverting power supplies.

https://www.maximintegrated.com/en/app-notes/index.mvp/id/2031

That was a good question.  Thanks for asking.
Carroll

[synchro1]

This has been my position the entire time:

"In fact we can have any number of applied or induced Emf's in a circuit acting in different directions however the sum of the Emf's will determine the direction of the current flow".

[SeaMonkey]

Excellent suggestion Carroll.

Also, there are a number of videos on the subject
as well:

How to select a Boost Converter

How does the Boost Converter work?

There are lots of videos on YouTube about
Boost Converters.  Learning has never been
easier!

Some interesting channels:

Mr. Carlson's Lab  (how to fix/restore things)

Eric Goodchild

EEVblog  (very lively)

z1power

TRX Bench  (for those who like to fix things)

[forest]

I know I know, but don't you think that if there is additional current generated due to magnetic field collapse of coil in boost inverter then it could be used to create overunity  converter ? If this is only due to combined higher emf "squeezing" electrons in output capacitor then obviously we end up with some 99.99% efficiency.