Pulsing a Permanent Magnet on/off

[gyulasun]

@Golden Mean

I redrew your schematic because it contained some fatal drawing mistakes.

I included a current limiting resistor in the positive wire of the battery to save the MOSFET from the several ampers of current when it switches on, (one possible explanation for burning your FETs is the lack of this resistor).

I did not include your 3V gate supply batteries in the modified schematic because you can use the 12V battery itself to control the gate via the reed switch, ok?  Resistor R1 discharges the gate-source inherent capacitor when the reed is also off, use any value between 2-3 kOhm.

I indicated a MOSFET type, IRF840 (500V 8A)  but any similar or better rated can be used. (IF you happen to use this type, then the value of R2 should be chosen 2 Ohm at least to bring down current below 8A from the 12V battery, ok?)

The IRF840 is an N-channel type, meaning its gate should get a positive voltage polarity with respect to its source to be able to control it. Also the drain should get  a positive polarity from any supply with respect to the source electrode. (For P-channel FETs all polarities are just the opposite.)

rgds,  Gyula

Thank you for your excellent reply and offer to assist.  Attached is a PDF schematic and brief explanation of the pulse motor setup.

I am uncertain about the direction of current flow from the 3 volt power supply to the gate (G) of the MOSFET transistor... 
Does the charge direction matter to trip the gate (G)?

I am uncertain about the connection to the MOSFET at the source (S) and drain (D) to get the proper direction of the charge flow to block magnetic flux in the bolt...
Should the 12 volt testing battery be connected to the source (S) or the drain (D) and in which direction?

Thank you for your consideration.

Peace,
~ Golden Mean

[Low-Q]

@LowQ:

Let's divide the south pole of a magnet for illustration purposes.  This will also apply to the north pole, but we'll only talk about the south pole to keep this simple.

Half of the south pole is a good guy and the other half of the south pole is a bad guy.  The bad guy destroys all the energy that the good guy provides.  The bad guy is known as the sticky spot.  The good and bad guys can switch their roles depending on their operation.  So, you will always have a good and bad guy.

Look at my corrected drawing for a second time.  The metal pieces are separated.  The top stator will attract one of the rotor magnets while the bottom stator will repel another magnet.  These guys are both good at the same time and are both providing us with energy. 

Let's say the good guy provided 100 units of energy and the bad guy provided 100 units of energy (In a normal magnet motor the bad guy doesn't provide anything, instead he would destroy the 100 units of energy that the good guy provided).  We now have 200 units of energy.  We'll destroy the 100 units of energy that the bad guy normally doesn't provide for the connecting and disconnecting of the two stators in order to keep them both good (In a normal magnet motor, this would destroy all the energy that was gained) .  We now have 100 units of energy minus friction after a complete cycle.  A cycle is a complete pass of two rotor magnets passing both stators.  Also, the top stator in the drawing should be curved to the rotor (poor drawing).

I will agree with you that things don't always work according to what is on paper or according to theory.  Do you understand what I'm trying to say?  I'm not good at putting my thoughts in writing.   

The sticky spot will be the stators itself. Look at the flux between the two statormagnets. It will jump almost directly to the other statormagnet and not contribute any useful attraction or repell of the rotormagnets. Left you have two statormagnets that is pulled together via the fluxpath through the metal pieces. So if you want to remove the statormagnet at properiate timing, they will be hard to move.

Another thing is that the "neutral" zone, somewhere in between the stator magnets, is more attractive than a repelling zone, so there will be a sticky spot in that direction - a direction opposite of the desired rotation.

Look at the forces with the magnet wheel and only the metal pieces, then look at it with the magnet wheel with only the stator magnets. Calculate a number of forces in given angels separately. Then it is then easier to predict the result when those are combined. Because it does not happen any spooky when you combine magnetic material, as the metal pieces, with magnets. You just make it more complex and less surveyable.

You should however try it anyway. Results, even if not good, are nice to have for later experiments.

Vidar

[Golden Mean]

@Golden Mean

I redrew your schematic because it contained some fatal drawing mistakes.

I included a current limiting resistor in the positive wire of the battery to save the MOSFET from the several ampers of current when it switches on, (one possible explanation for burning your FETs is the lack of this resistor).

I did not include your 3V gate supply batteries in the modified schematic because you can use the 12V battery itself to control the gate via the reed switch, ok?  Resistor R1 discharges the gate-source inherent capacitor when the reed is also off, use any value between 2-3 kOhm.

I indicated a MOSFET type, IRF840 (500V 8A)  but any similar or better rated can be used. (IF you happen to use this type, then the value of R2 should be chosen 2 Ohm at least to bring down current below 8A from the 12V battery, ok?)

The IRF840 is an N-channel type, meaning its gate should get a positive voltage polarity with respect to its source to be able to control it. Also the drain should get  a positive polarity from any supply with respect to the source electrode. (For P-channel FETs all polarities are just the opposite.)

rgds,  Gyula

Thank you Gyula for reviewing and correcting my schematic.  However, there will have to be resistor going to the reed switch as I've already welded two by trying to run the coil current directly through the reed switch and skipping the MOSFET altogether.  What type of resistor should I use to reduce the voltage down to around 3 volts?
Also, attached is the spec sheet for the MOSFET I am working with (currently anyway )

I'll post my results as soon as I have some time to do some more testing (likely Friday night).

Thanks again.

Peace,
~ Golden Mean

[Golden Mean]

Sorry, accidental double post...

[gyulasun]

Thank you Gyula for reviewing and correcting my schematic.  However, there will have to be resistor going to the reed switch as I've already welded two by trying to run the coil current directly through the reed switch and skipping the MOSFET altogether.  What type of resistor should I use to reduce the voltage down to around 3 volts?
Also, attached is the spec sheet for the MOSFET I am working with (currently anyway )

I'll post my results as soon as I have some time to do some more testing (likely Friday night).

Thanks again.

Peace,
~ Golden Mean

Hi,

The data sheet shows the TIP47-50 npn bipolar power transistors specs, this is NOT a MOSFET as you can also read it.  Why did you think it is a MOSFET and indicated in your PDF file its electrodes as G, D and S? It should be B, C and E.

This transistor has a max allowed peak collector current of 2A as you can see so the value of the resistor R2 I included in the modified schematic should be increased to at least 9-10 Ohm, ok?

Now if you really have got TIP48 bipolar transistors (and not MOSFETs) than you have to modify my schematic: you have to insert a resistor in series with the reed switch where the left hand side of the reed goes to the common point of G (which is now the B or base of the transistor) and R1, ok?   The value of this series resistor can be between 8-9 kOhm (maybe better to use a 10 kOhm trimmer potmeter, place also in series with its wiper a 1kOhm resistor), ok? now I have no time to update the schematic, if you do not understand, then I will draw it tomorrow.

Your reed switches was destined to weld when you used them directly, without transistor, because they cannot handle the too high current (your coil copper resistance is under 1 or around 1-2 Ohm and you connected it to a 12V battery via the reed, use Ohms law to figure out the current!)

rgds, Gyula