Sharing ideas on how to make a more efficent motor using Flyback (MODERATED)

[MileHigh]

I believe I posted what happens if the cap were not there one page back.

http://overunity.com/16167/sharing-ideas-on-how-to-make-a-more-efficent-motor-using-flyback-moderated/msg466132/#msg466132

"I had looked through my vids to see if i had one, but dont....  I remember trying to get a bemf spike into a higher henry coil and the higher H coil seemed to block most of the spike rather than take advantage of the full potential. Like a subwoofer crossover coil, it blocks out the high frequencies.  So the capacitor across your higher inductance coil probably loads up first then delivers it charge to the parallel coil?

Mags"

Mags

Magluvin.

Sorry for not acknowledging your comments.  You are right, the capacitor loads up first and the inertia of the coil prevents any significant current flow.  Note from Laurent's scope shots that the capacitor loads up in about 75 microseconds, which is quite fast.  The "flywheel of the coil" has so much inertia that it has barely even budged after 75 microseconds.

With respect to the situation where there is no capacitor, you can simply extrapolate from Laurent's scope shots and imagine the capacitor getting smaller and smaller.  The capacitor voltage will get higher and higher and the pulse width will get narrower and narrower.  At the idealized limit you have an infinitely high voltage spike and an an infinitely narrow pulse with - and yet there is still a finite amount of energy in this idealized pulse.

The flywheel version:  If you have a spinning flywheel next to a stationary flywheel on the same shaft, and they are the same size and weight, what happens when the two of them come into contact?

There are two cases you can examine for this:

1)  Imagine there are friction plates like a clutch setup when the two flywheels make contact.  There will be friction losses as the clutch plates come together.  If flywheel A was spinning at 100 RPM and flywheel B was stationary, then after contact the pair of flywheels will be spinning together at 50 RPM.  You will have lost one-half of the rotational energy through mechanical friction when the clutch plates make contact.   This is also identical to shorting two capacitors together and when the current rushes and voltages balance you lose one-half of the energy in the wire resistance.  This is also equivalent to a perfectly inelastic collision between two masses.

2) Imagine the impossible, just like magic the two flywheels are instantly fused together as one.  The spinning flywheel will impart an infinite amount of torque on the stationary flywheel for an infinitely short amount of time.  There is your infinitely high voltage spike for an infinitely short amount of time.  The final speed in this case will not be 50 RPM, it will be 70.71 RPM.  No energy will be lost after the magical creation of the unified flywheel.  This is equivalent to a perfectly elastic collision between two masses.

On the bench, when the drive coil outputs its current pulse into the secondary coil and there is no capacitor, you get an approximation to case 2) above.  You can assume that you lose some energy, but much less than losing 50%.   The parasitic capacitance in the interconnect wiring will absorb the voltage spike that comes as a result of the current pulse from the drive coil.  The resulting high-voltage spike is the "extreme torque for a very short time" that will get the secondary coil "rolling."  Naturally, there will be a risk of dielectric breakdown in the air when this happens.

MileHigh

[synchro1]

@Milehigh,

What effect does the EMF induced into the high-voltage coil from the passing rotor magnet have on the capacitor discharge curve?

[Magluvin]

Magluvin.

Sorry for not acknowledging your comments.  You are right, the capacitor loads up first and the inertia of the coil prevents any significant current flow.  Note from Laurent's scope shots that the capacitor loads up in about 75 microseconds, which is quite fast.  The "flywheel of the coil" has so much inertia that it has barely even budged after 75 microseconds.

With respect to the situation where there is no capacitor, you can simply extrapolate from Laurent's scope shots and imagine the capacitor getting smaller and smaller.  The capacitor voltage will get higher and higher and the pulse width will get narrower and narrower.  At the idealized limit you have an infinitely high voltage spike and an an infinitely narrow pulse with - and yet there is still a finite amount of energy in this idealized pulse.

The flywheel version:  If you have a spinning flywheel next to a stationary flywheel on the same shaft, and they are the same size and weight, what happens when the two of them come into contact?

There are two cases you can examine for this:

1)  Imagine there are friction plates like a clutch setup when the two flywheels make contact.  There will be friction losses as the clutch plates come together.  If flywheel A was spinning at 100 RPM and flywheel B was stationary, then after contact the pair of flywheels will be spinning together at 50 RPM.  You will have lost one-half of the rotational energy through mechanical friction when the clutch plates make contact.   This is also identical to shorting two capacitors together and when the current rushes and voltages balance you lose one-half of the energy in the wire resistance.  This is also equivalent to a perfectly inelastic collision between two masses.

2) Imagine the impossible, just like magic the two flywheels are instantly fused together as one.  The spinning flywheel will impart an infinite amount of torque on the stationary flywheel for an infinitely short amount of time.  There is your infinitely high voltage spike for an infinitely short amount of time.  The final speed in this case will not be 50 RPM, it will be 70.71 RPM.  No energy will be lost after the magical creation of the unified flywheel.  This is equivalent to a perfectly elastic collision between two masses.

On the bench, when the drive coil outputs its current pulse into the secondary coil and there is no capacitor, you get an approximation to case 2) above.  You can assume that you lose some energy, but much less than losing 50%.   The parasitic capacitance in the interconnect wiring will absorb the voltage spike that comes as a result of the current pulse from the drive coil.  The resulting high-voltage spike is the "extreme torque for a very short time" that will get the secondary coil "rolling."  Naturally, there will be a risk of dielectric breakdown in the air when this happens.

MileHigh

I hadnt ever put it together that the flywheel and inductor are both not going to react heavily to impulse hits. Like it would be very hard to get a flywheel to oscillate one way then the other at high freq.  So the cap with the coil would be the flywheel with a spring.  The smaller the cap, similarly the tighter the spring.



For some reason the word inductor is underlined in red as a misspell as I write it here. 

Mags

[Magluvin]

@Milehigh,

What effect does the EMF induced into the high-voltage coil from the passing rotor magnet have on the capacitor discharge curve?

Was thinking about that earlier, in a way.  Like how a larger inductance will block an 'electrical' pulse, but a magnetic pulse induction would have no problem getting current to flow in the large inductance.

Mags

[synchro1]

Was thinking about that earlier, in a way.  Like how a larger inductance will block an 'electrical' pulse, but a magnetic pulse induction would have no problem getting current to flow in the large inductance.

Mags

@Mags,

Woopjump produces a scope shot with the auxiliary coil separated from the rotor for comparison in his first video. A vastly greater amount of voltage appears on the scope when he repositions it close to the rotor. Woopy takes wide notice of it but doesn't offer any explanation.