Inductive Kickback

[verpies]

In your second example you are putting 5000 watts into the load.  Where did that extra 4900 watts come from?

No, only the initial instantaneous power dissipated into the load (the 100Ω resistor) is I²R.

The energy stored in the inductor is ½LI² in both cases

[MileHigh]

@Citfta,

This is my all time favorite pulse motor build by Igor Moroz; I've watched it at least a hundred times. It's as close to a self runner as anything I've ever seen and it's simpler then anyone can imagine. I love it. Please look at it more then once. It's only two minutes long. Study it:

https://www.youtube.com/watch?v=vWvI7T7h3tk

Yes I looked at the clip and Igor is dead wrong.   A few years ago he was making clips where he was always saying that his diodes were redirecting current back to the source battery.  I pointed out to him that that was wrong and he acknowledged it and then just shrugged it off.  He probably had at least a dozen clips with that mistake in them.

It's safe to assume that Igor is just an ordinary guy, an amateur, so don't make the mistake of taking what he says in his clips as always being true.

Here is a comment on Igor's clip from three years ago:

<<< @Mopozco Great, thanks for sharing results. The collapsing field of a coil wants to keep current flowing in same direction, coil behaves like battery in series with your 1.5V battery ~(-)batt(+)~~~(-)coil(+)~. Please confirm direction of LED on your drawing. Is LED cathode connected to coil so that when current from collapsing field at higher voltage (bemf) exceeds LED Vf it flashes it? This would keep the current flowing in the same direction not in opposite direction as shown on your drawing.  >>>

The guy is probably right and Igor had the LED in the opposite direction that he thought it was.  Alternatively, I don't know if an LED will light up if you slam current through it in the wrong direction but you never know.

It all goes back to the messed up culture on the forums of being too polite to correct your peers when they make a mistake.  It creates a regimen of enforced foolishness and stupidity.  I can't tell you how many times I have seen inane ridiculous postings by people and people on the forum say things like, "Thanks for your interesting ideas!"  It's ridiculous and totally counterproductive.

I just posted that Tinman was wrong about the current flow in an inductor.  Chances are if I didn't post the correction, then nobody would have corrected him.  That would turn what is supposed to be an informative educational thread into more uncorrected disinformation, messing up people's understanding of basic basic electronics, yet again.

[synchro1]

Hi Cifta and Synchro and all

If i posted above it is not to get  what i can get from all text books about physic.

My questions are  very clear :

1- at the end of the pulse, on the scope shot, the input current from the power source has totally vanished  yes or not ?

2- The current has built a magnetic field in or around  the inductor and this magnetic field has been " used "  to propel the rotor magnet yes or not ?

3- so the current is not stored in the magneticfield but has been used the give the rotor magnet a kinetic energy yes or not ?

4-So if the magneticfield  collapses and by shrinking it crosses the wires of the coil and redo a new current does it mean that the magneticfield can be used twice yes or not ?

And just for the dessert

A small video showing that the flybackspike can be really powerfull and destroying as  every body knows very well

https://youtu.be/TAx7Y0UIyHA

good night at all

Laurent

@Laurent,

Wear your welding glasses!

[citfta]

Hi Cifta and Synchro and all

If i posted above it is not to get  what i can get from all text books about physic.

My questions are  very clear :

1- at the end of the pulse, on the scope shot, the input current from the power source has totally vanished  yes or not ?
Yes

2- The current has built a magnetic field in or around  the inductor and this magnetic field has been " used "  to propel the rotor magnet yes or not ?
Yes

3- so the current is not stored in the magneticfield but has been used the give the rotor magnet a kinetic energy yes or not ?
The current builds the magnetic field and the magnetic field gives the rotor magnet the kinetic energy

4-So if the magneticfield  collapses and by shrinking it crosses the wires of the coil and redo a new current does it mean that the magneticfield can be used twice yes or not ?
Yes that is why we can send current to the cap after the reed switch has opened.

And just for the dessert

A small video showing that the flybackspike can be really powerfull and destroying as  every body knows very well

https://youtu.be/TAx7Y0UIyHA

good night at all

Laurent

[synchro1]

Yes I looked at the clip and Igor is dead wrong.   A few years ago he was making clips where he was always saying that his diodes were redirecting current back to the source battery.  I pointed out to him that that was wrong and he acknowledged it and then just shrugged it off.  He probably had at least a dozen clips with that mistake in them.

It's safe to assume that Igor is just an ordinary guy, an amateur, so don't make the mistake of taking what he says in his clips as always being true.

Here is a comment on Igor's clip from three years ago:

<<< @Mopozco Great, thanks for sharing results. The collapsing field of a coil wants to keep current flowing in same direction, coil behaves like battery in series with your 1.5V battery ~(-)batt(+)~~~(-)coil(+)~. Please confirm direction of LED on your drawing. Is LED cathode connected to coil so that when current from collapsing field at higher voltage (bemf) exceeds LED Vf it flashes it? This would keep the current flowing in the same direction not in opposite direction as shown on your drawing.  >>>

The guy is probably right and Igor had the LED in the opposite direction that he thought it was.  Alternatively, I don't know if an LED will light up if you slam current through it in the wrong direction but you never know.

It all goes back to the messed up culture on the forums of being too polite to correct your peers when they make a mistake.  It creates a regimen of enforced foolishness and stupidity.  I can't tell you how many times I have seen inane ridiculous postings by people and people on the forum say things like, "Thanks for your interesting ideas!"  It's ridiculous and totally counterproductive.

I just posted that Tinman was wrong about the current flow in an inductor.  Chances are if I didn't post the correction, then nobody would have corrected him.  That would turn what is supposed to be an informative educational thread into more uncorrected disinformation, messing up people's understanding of basic basic electronics, yet again.

@Milehigh,

The LED is reverse biased in Igor's video. This is the trick of the build. You have too much to say about this intrepid inventor for someone who never uploaded even so much as one test video of any kind.

You pasted some copied comments from Igor's video, but you neglected to copy this one by Lidmotor:

"I have been doing this same thing and it seems to work really well.  It saves the reed switch contacts also".