Effects of Recirculating BEMF to Coil

[poynt99]

Luc,

Is your setup something like this?:

Cap (charged to 170V, and commoned to "gnd")=>+coil lead=>-coil lead=> MOSFET Drain=> MOSFET Source (commoned to "gnd")

If this is how you have connected everything, then you have 170V across the coil when the MOSFET is ON.

If you accidentally connected the MOSFET Drain/-coil lead to ground through the iron tip, then this would have caused the full 170V to go through the coil. I am not sure why the MOSFET would have blown unless somehow the gate voltage went way up in voltage also.

.99

[gotoluc]

Hi everyone,

I have made a new video with a better quality camera I now have for all future videos.

I made this new video because something was bothering me about my previous conclusion using my good quality meter to measure the Watts Energy of the pulsing circuit compared to using straight DC. I talked to my Engineer friend and he has confirmed to me what I was thinking. Watts energy has nothing to do with Voltage since you can have thousands of volts going through a resistor and there could be no heat if there is no Watts energy. So Watts energy should be measured by heat dissipation at the Resistor regardless of the voltage.

So what I'm getting at is, since it's so difficult to measure the Energy used by these kinds of circuits lets just measure the heat dissipated in a resistor at the input of the circuit compared to the heat dissipated at the output.

I have redone a video using a visual restive load on the input with the circuit functioning with an 8% duty cycle to compare it using the same load with straight DC and the results are quite different then what my quality meter was calculating.

I know many will be saying that this is not the way to measure. However I'm not measuring! the bulb is only a visual display of Energy and nothing else regardless of the voltage going through it because it's resistive.

Also note that I will be redoing the test over but using standard resistors and measuring the heat dissipated at the input compared to the heat dissipated at the output and posting the video next week at some time. In the meanwhile this gives us something to think and talk about.

Video link: http://www.youtube.com/watch?v=HpaP__5Kd38

Luc

[wattsup]

@gotoluc

Your last video was spot on (expect for using the BEMF word - lol). Old habits are hard to break.

What you have shown is the super efficient way of raising the magnet using pulsed DC combined with the off-pulse flyback, compared to the normal energy hog method of raising the magnet using straight DC. 

Of course we cannot concluded any type of OU aspect here and this is not even important at this stage, it is just a confirmation of your efficiency level.

What would be interesting is to now run this same test but with your batteries again and add a return charging diode to the battery to see if the flyback can still maintain the magnet height while having some extra flyback energy that the coil could maybe not have taken advantage of, to then recharge the battery. A switch on the batttery charging diode would show the difference of normal flyback mode and then with added flyback battery recharge. But maybe that's taking it to a very next level that you are not near yet.

Good work.

wattsup

[gotoluc]

Hi everyone,

I made a new video using standard resistors of equal value on the input side and on the recirculated Inductive flyback side pre entry of the coil. I have measured the heat on each but have not wet come up with a better way of measurement that will satisfy all but I am working on it.

New Video: http://www.youtube.com/watch?v=WsmPyUzZtgQ

In this test it is very very difficult for me to understand how energy could slip though the input 22 Ohm resistor and leave basically no heat and end up in the collapsing field side resistor at higher temperature then the boiling point and also do work pushing up a one pound magnet over 3/8 of an inch off the coil. We cannot consider voltage as having anything to do with the effect since it has no heat Energy. So what is doing this?

Please find the attached scope shot measured across the 22 Ohm input resistor and let me know if you can calculate this.

Luc

[gotoluc]

@gotoluc

Your last video was spot on (expect for using the BEMF word - lol). Old habits are hard to break.

What you have shown is the super efficient way of raising the magnet using pulsed DC combined with the off-pulse flyback, compared to the normal energy hog method of raising the magnet using straight DC. 

Of course we cannot concluded any type of OU aspect here and this is not even important at this stage, it is just a confirmation of your efficiency level.

What would be interesting is to now run this same test but with your batteries again and add a return charging diode to the battery to see if the flyback can still maintain the magnet height while having some extra flyback energy that the coil could maybe not have taken advantage of, to then recharge the battery. A switch on the batttery charging diode would show the difference of normal flyback mode and then with added flyback battery recharge. But maybe that's taking it to a very next level that you are not near yet.

Good work.

wattsup

Thanks for the post wattsup ... ya that term keeps slipping out of my mouth if I 'm doing too many things in the same time

As for charging a battery with flyback. That's something I've tried many times in the past and have not shown any gain. I think the flyback is best used to create heat and or electro mechanical power with an air core coil and powerful magnet.

I'm happy with the results so far anyways. Others can test the battery thing!... by the way, wattsup with the others you can't be the only one interested in this

Luc