Effects of Recirculating BEMF to Coil

[rave154]

GYULA,

repeating my previous test but using the 4937 diodes and no other changes

after 20 seconds running.....



joules in CAP-1 = 0.0395 (0.01587)

joules in CAP-2 = 0.02475 (0.00618)

total in CAPs = 0.06425 (0.02205)

joules used in battery = 0.455 ( same as last time )

ratio of input to ouput 14.1% (4.8%)



David. D

[gyula]

Hi David,

You have achieved over a 200% improvement wrt to the previous test by just changing for a better diode type but the result is still miserablely low lol.

I cannot give you much more hint on the components, maybe changing the duty cycle and the switching frequency you may be able to improve further on.

keep up good work.

rgds, Gyula

[rave154]

GYULA,

im not sure here, cos im no where near an expert,

but dont those two test results seem to imply that the slow-lazy diodes are absorbing more of the flyback spike, where-as the faster diodes allowed more of it through ( maybe not ALL of it? )...

soo...we need ....even faster diodes even than the ones in the 2nd test....OR.... a different circuit design to re-route the flyback not using diodes...and using maybe timed switching or something? ( tesla switch ??? )

ahhh the questions are endlessssssssssssssssssssssssssssssssssss lol

David. D

[gyula]

Hi David,

You can surely use an even faster diode because the one I first referred to and you happened to just to have that type has a decent 150ns reverse recovery time while other fast diode types have got a 25-35ns and certain smaller current types like 1N4148 or the older 1N914 have got a 4-5ns switching time.

You may try to connect two 1N4148 or two 1N914 diodes in parallel if you happen to have some in the junk box (parallel to increase forward current rating from about 100mA to 200mA) and just do the same test in the same circuit because their 4-5ns fastness represent the ultimate in this respect and see how many volt you can catch from the flyback pulse via them.

Another advice is what member poynt99 has wrote in his new thread, calculate your L/R time from the actual coil inductance and from all the resistances that are in series with this coil, incl battery or power supply inner resistance and then use a pulse width which is only 4 or 5 times bigger than the L/R time. This way you insure there is no more input energy that is higher (so it is wasted) than is needed to energize the coil.

Because actually what you have been trying to test is a DC-DC converter, the practical efficiency is normally over 80-90% for off the shelf units, in selected cases 93-95%, and all such converters utilize the regained flyback pulse. It is true such converters come in integrated chip or encased forms.

rgds, Gyula

[gotoluc]

Forgive me if this had been answered before.

What is the resistance of both coil in video bellow?

YouTube - Effect of Recirculating BEMF back into Coil test 1


I think if the coil-collapse-current powered coil have much less resistance than the main coil, the power will be greater since I think there would be more current passing trough the child coil than bouncing back in the main.

I think vibration happen because different polarity between main and child.

Hi sucahyo,

sorry for the reply delay.

The coil in (Recirculating BEMF back into Coil test 1) measures 200 Ohms and 94mH Inductance. The coil under it is a sense coil for my Oscilloscope to get a view of what is going on in the main coil. It has about 20 turns and has next to no resistance.

Hope this helps

Luc

[gotoluc]

Hi Gotoluc,

first of all thanks for sharing all the results of your hard work and your detailed videos. I have a question regarding video 8. Do you get the same result without the magnet on top?
The reason I'm asking is that I've been working for a long time on Bedini solid state circuits and have tried pretty much everything I could think of.
In one setup I did I had one circuit charging a HV cap which was the source of the next ciruit, ranging from about 100 to 300V. So basically the second part is what you did, a flyback circuit with a HV supply(actually a buck converter). The switching was done by HV mosfets at a frequency and duty cycle dictated by the coil dimensions and load, the latter being batteries or a big cap with a lamp across.
With "dictated by the coil and load" I mean where it naturally wants to run at. I have done many selftriggering setups in the past so after a while you get a feel for how to set a circuit like this for the most efficient frequency and duty cycle, simulating a selfriggering system withouth the drawbacks of a trigger winding.
Anyway, the circuit was very efficient but not over the hill, although it had very sharp switching.
Since we basically did the same thing except for the magnet, and you got that kind of a result I can't but wonder if you get the same without it...
Again, thanks for your work

regards,
Mario

P.S. What is the wattage of your bulbs? You say 12V but not how many amps or watts.

Hi Mario,

the magnet has no positive effect!... in fact the efficiency get a little better without it.

The bulbs used in test 8 draw 250ma at 12.88vdc

Luc

[gotoluc]

Hi everyone,

I tried to replicate my test 12 video using a capacitor instead of the battery to try to understand why there was so much difference between the two tests (11 and 12) and I found out that one of my 3 batteries is defective and that was the main cause of the huge difference. So I deleted test 12 video so not to mislead anyone. Anyways, I'm replacing it with the one below.

This video demonstrates that a Resistor can attain the same amount of heat connected directly (no Coil) to the pulse circuit then connected to the inductive kickback side of a coil. Both tests were tuned to use the same amount of energy from the Series battery bank.

What I find interesting is, you would think that by adding a coil it would make it less efficient but it seems to be as efficient as without the coil.

So where am I going with this!... well, if we add a coil in the circuit and it cost nothing, and we can still produce the same amount of heat that's good! since the the coil could be doing work, like turning a motor and then the inductive kickback will keep the hot water tank hot or something of that kind.

Just sharing ... let me know what you think.

Video Link: YouTube - Effect of Recirculating BEMF to Coil test 12

Luc

[rave154]

good stuff as usual GOTO

[Michael John Nunnerley]

On the right track, I think

Mike

[SkyWatcher]

Hi Luc, what I was getting at was that since the permanent magnet is somewhat stationary and at TDC in your previous tests, that it doesn't create a counter emf to your applied pulsed input as you may already know. Then again I've built a small Adams motor in the past that caused the coils to become cold, well below room ambient temp. so I am definitely not saying that permanent magnets are out of the question. In Adams motors, the generated counter emf created by the magnets departing TDC when the field neutralizing pulse is on, as far as i know we can get this back and so his reluctance motor design would be a good choice if using permanent magnets on rotor.
peace love light
Tyson

[gotoluc]

Hi Luc, what I was getting at was that since the permanent magnet is somewhat stationary and at TDC in your previous tests, that it doesn't create a counter emf to your applied pulsed input as you may already know. Then again I've built a small Adams motor in the past that caused the coils to become cold, well below room ambient temp. so I am definitely not saying that permanent magnets are out of the question. In Adams motors, the generated counter emf created by the magnets departing TDC when the field neutralizing pulse is on, as far as i know we can get this back and so his reluctance motor design would be a good choice if using permanent magnets on rotor.
peace love light
Tyson

Yes Tyson I would agree that the Adams Motor and timing design would be a good choice

Thanks for your input.

Luc

[SkyWatcher]

Hi Luc, no problem. And of course as your video shows, when the field collapses we route it back into the coil and it gives it another repulsive kick and probably a succession of smaller and smaller repulsive kicks. There would be a sweet spot where the input stays the same or reduces as you've seen in your tests as well.
peace love light
Tyson

[SkyWatcher]

Hi Luc, could you try this circuit since you have that thermal meter device and I only have my fingers to test for speed of temp. rise. If you could pulse your resistor at a certain power draw and measure temp., then use the circuit I am posting and set the power draw to the same and measure the heat. I used a 200 milliohm inductor and 10 ohm resistor so I only had to adjust the 555 pots slightly to make same draw. I have found this gives a much faster heat rise in the resistor although not sure what the final stabilized temperature would be due to not having a meter device for it yet. Thanks.
peace love light
Tyson

[gotoluc]

Hi Tyson,

I can do the test but need to know what you use to measure amp draw. Also at what pulse frequency, duty cycle and feed voltage you are using for the test. I would also need information on the coil (wire gauge, diameter of coil center opening, turns of wire, layers of wire) so to have a comparable test as yours.

Thanks

Luc

[SkyWatcher]

Hi Luc, never mind, the more I'm testing it seems the same as your results although your circuit would be better for running a motor or something. My results were confusing me because the temp. of the resistor wasn't at the exact same starting temp. for comparative tests. Though of course when tuned properly higher heat as in Ainslies circuit would manifest. I'm glad you have highlighted the fact creating the magnetic field in the coil costs nothing as my results show as well though using a little different circuit, great stuff.
peace love light
Tyson