Shorting coil gives back more power

[woopy]

Hi all

Thanks fo every contributers

let's go on

it is a very interesting subject and a lot of of remaining work

http://www.youtube.com/watch?v=k7SeAzDhXK4

good luck at all 

Laurent

[gyulasun]

Hi Laurent,

Ok, just take your time, this is not a race, at least I do not consider it that way, just take it easy.   

Gyula

Hi Gyula

Thanks a lot for this info about Doug shematic

will study and try it ASAP

for today, i could replicate Romero uk result  and i tried LED in serie and in parallel i will report the result because it is not so simple and i want to be sure before saying anything

For info i tried a bigger coil with much less impedance and also inductance with good results also ,i will go on the testing ( see the pix with very strong and probably too large pulse at the top and bottom of the sine wave)

good luck at all

Laurent

[gyulasun]

Hi Laurent,

Late last night we wrote at about the same time I noticed but had to finish.

Good video, thanks and my question is whether you simply has not redrawn your schematic you showed at 1:22 on the two Hall sensors? I mean the corrections I showed in this schematic:
http://www.overunity.com/index.php?action=dlattach;topic=10398.0;attach=51179

The 22k (or now the 10kOhm) resistor's right hand side leg cannot connect to the common point of the source electrodes: that is what I meant by editing out your black wire with a gray line to mask it, ok? And you have to connect the 9V battery negative not only to the HAll device negatives but to the common source electrodes, too this is what I showed in blue line.

Please confirm how these two 'problems' are connected in reality on your board.

My other question is on the Hall sensor types: you indicate SS443A which are unipolar types so they react on normally to one dedicated magnetic pole, I suppose it is the South?  IF this is so, then how can you use the same type for reacting on the the opposite magnet pole?

Thanks, Gyula

PS More on later.

[gyulasun]

Hi Laurent,

While the modifications in the Hall switch schematic are needed as I wrote above, there is still a problem I am going to explain.
When I showed you this reed switch controlled schematic:
http://www.overunity.com/index.php?action=dlattach;topic=10398.0;attach=51183 
the 10kOhm was indeed between the gate-source electrodes, to discharge the C_GS capacitance of the MOSFETS at switch off, otherwise this capacitance would keep the 9V from the battery (in spite of the reed already went in the off position) for a longer time, the FETs could not switch off when you you want them).

Now that you use Hall switch, it does NOT have two independent switch points like a reed has,  only one, the so called output, designated with letter o in the SS443A data sheet. This means that you simply cannot use this Hall switch at the same place where the reed is shown. This is why I wrote and showed in an edited schematic how the 'correct' connections should be done.
SO the 'problem' with this modified schematic is that the Hall cannot help but control the FETs with an opposite duty cycle: when the Hall sensor switches on from the coming (South) magnetic pole, then its "o" output goes to the negative ground and switches OFF the FETs! And when the magnet leaves this Hall sensor, then its "o" output goes in fact into an open circuit BUT there is the 22k (or now 10k) which makes this output to be a positive 9V with respect to the Hall sensor's negative leg & with respect to the FETs source electrodes  i.e. the FETs switch ON!
So what is missing is a device which inverts the Hall output and this is the 2N2222 or any other NPN bipolar transistor as shown in Doug Konzen recent schematic I showed you the other day.

To make it more understandable for you, I modified Doug's schematic to
your present needs: I left out the MOSFET driver 4422 integrated circuit.
What is remained is one Hall device that drives a 2N2222 transistor and this transistor drives the MOSFETs. 

I hope now all is clear and sorry I have not realized this 'problem' yesterday.

I attached the modified schematic below.  OF course you can use the
4422 driver chip too, it will make the switch ON & OFF times very quick whenever the Hall is positioned correctly.  For the time being, I advise you to use only one Hall sensor, say, to switch at the positive peak sine wave and when it runs ok then you could connect a second Hall and position it so that it would control the FETs at the negative peaks of the induced sine waves.  The latter Hall could act also on a South pole like the first one but position it slightly offset from the first Hall.

If you wish to use driver chip like the 4422 as shown earlier, then I suggest buying 4421 instead, which is the inverting version of 4422, so that the 2N2222 transistor is not needed for inverting the output response of the Hall sensor. When you wish I can draw a new schematic with the 4421 too.

rgds,  Gyula

[joefr]

Thanks Gyula for new schematic and detailed explanation

I will be ordering components for this setup, so could you please draw new schematic with the 4421 driver too.
And cay you specify which Hall sensor model is needed in this setup ?


Here I found some info about Hall Sensors:

Unipolar Hall-Effect Sensor:
Unipolar Hall-effect sensor ICs, often referred to as "unipolar switches," are operated by a positive magnetic field. A single magnet presenting a south polarity (positive) magnetic field of sufficient strength (magnetic flux density) will cause the device to switch to its on state. After it has been turned-on, the unipolar IC will remain turned-on until the magnetic field is removed and the IC reverts to its off state.
http://www.allegromicro.com/en/Products/Design/unipolar/index.asp

Omnipolar Switch Hall-Effect:
Omnipolar Hall-effect sensor ICs, often referred to as "omnipolar switches," are a type of digital output Hall-effect latching switches that operate with either a strong positive or strong negative magnetic field. This simplifies application assembly because the operating magnet can be mounted with either pole toward the omnipolar device. A single magnet presenting a field of sufficient strength (magnetic flux density) will cause the device to switch to its on state. After it has been turned-on, the omnipolar IC will remain turned-on until the magnetic field is removed and the IC reverts to its off state. It latches the changed state and remains turned-off, until a magnetic field of sufficient strength is again presented.
http://www.allegromicro.com/en/Products/Design/omnipolar/index.asp

Latching Switch Hall-Effect:
Latching Hall-effect sensor ICs, often referred to as "latches," are digital output Hall-effect switches that latch output states. Latches are similar to bipolar switches, having a positive BOP and negative BRP, but provide tight control over switching behavior. Latches require both positive and negative magnetic fields to operate. A magnet presenting a south polarity (positive) magnetic field of sufficient strength (magnetic flux density) will cause the device to switch to its on state. When the device is turned-on it latches the state and remains turned-on, even if the magnetic field is removed, until a north polarity (negative) magnetic field of sufficient strength is presented. When the negative field is presented, the device is turned-off. It latches the changed state and remains turned-off, even if the magnetic field is removed, until a south polarity (positive) magnetic field of sufficient strength is again presented.
http://www.allegromicro.com/en/Products/Design/latching/index.asp

Bipolar Switch Hall-Effect:
Bipolar sensor ICs are designed to be sensitive switches. (Note that the term "bipolar" refers to magnetic polarities, and is not related to bipolar semiconductor chip structures.) A bipolar switch has consistent hysteresis, but individual units have switchpoints that occur in either relatively more positive or more negative ranges. These devices find application where closely-spaced, alternating north and south poles are used, resulting in minimal required magnetic signal amplitude, Î"B, because the alternation of magnetic field polarity ensures switching, and the consistent hysteresis ensures periodicity.
http://www.allegromicro.com/en/Products/Design/bipolar/index.asp