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

[gotoluc]

For Synchro

I think what is confusing you about the current not reversing after the reed opens is you are not realizing the coil becomes the source of current and not a load.

You can easily prove this to yourself if you have a 2 channel scope.  Simply add a low value resistor like 1 ohm or so to the circuit Tinman has provided in series with only the coil.  Now watch the scope channels as you turn the coil on and off.  You will see the signal across the resistor only goes up as the coil is charged and discharged.  But the channel across the coil will show a reversal of polarity.  But obviously if the channel across the resistor doesn't change polarity then the current does NOT reverse.

If we use the old school idea of electron flow you can look at it this way.  The negative terminal of the battery has a surplus of electrons since electrons are negatively charged.  So when the reed switch is turned on electrons move from the negative of the battery into the bottom of the coil.  And electrons flow out the top of the coil back to the battery.  If we put a meter on the coil we see the top as positive and the bottom as negative because the excess of electrons is at the bottom of the coil.

Now when we turn off the reed switch the collapsing magnetic field wants to keep the electrons flowing in the same direction.  Since the coil is now the source and the current is still flowing in the SAME direction as before we now see the top of the coil as being more negative than the bottom.  The current has not changed direction but the polarity of the voltage has changed.

Respectfully,
Carroll

Excellent post and test suggestion Carroll

Thanks for taking the time to help

Luc

[gotoluc]

Thinking a bit more, and on topic....

I reposted Woopys circuit for reference below.

If you see the red x labeled 4, if you put a diode there, same direction as the one to the left of the x, the cap will discharge all of its charge through the coil only once.

Now for possibly an even better effect. Havnt tried but I think it would be a good thing if it works....

When the cap charges, then discharges through the coil with the added diode, the cap will fully discharge, and then some due to the flywheel effect of the coil, meaning the cap will end up with a charge reverse of what it started with. The possible advantage is, when the next spike comes from the primary drive coil, it will be facing a cap with a charge that is well willing to accept the spike as the polarities will be in series. So the spike enters the cap with help of the charge already in the cap. The possibility is that the cap may charge higher than without that added diode. Im pretty sure of it from my experience in this stuff.

Mags

Sounds very interesting Mags

Thanks for sharing

Luc

[synchro1]

For Synchro

I think what is confusing you about the current not reversing after the reed opens is you are not realizing the coil becomes the source of current and not a load.

You can easily prove this to yourself if you have a 2 channel scope.  Simply add a low value resistor like 1 ohm or so to the circuit Tinman has provided in series with only the coil.  Now watch the scope channels as you turn the coil on and off.  You will see the signal across the resistor only goes up as the coil is charged and discharged.  But the channel across the coil will show a reversal of polarity.  But obviously if the channel across the resistor doesn't change polarity then the current does NOT reverse.

If we use the old school idea of electron flow you can look at it this way.  The negative terminal of the battery has a surplus of electrons since electrons are negatively charged.  So when the reed switch is turned on electrons move from the negative of the battery into the bottom of the coil.  And electrons flow out the top of the coil back to the battery.  If we put a meter on the coil we see the top as positive and the bottom as negative because the excess of electrons is at the bottom of the coil.

Now when we turn off the reed switch the collapsing magnetic field wants to keep the electrons flowing in the same direction.  Since the coil is now the source and the current is still flowing in the SAME direction as before we now see the top of the coil as being more negative than the bottom.  The current has not changed direction but the polarity of the voltage has changed.

Respectfully,
Carroll

@Citfta,

That sounds pretty scientific. What both you and Tinman are proposing is that it's possible for electrical power to share current and voltage of opposite polarities. This is physically impossible! 

There is no "Left Over" old current in the primary coil after the violence of the magnetic field collapse; There is only new current and voltage of opposite polarity. There is no cause and effect between the old current and the new current. The old current is in the past behind the event horizon. The violence of the field collapse has utterly and with absolute finality obliterated any trace of the old current along with any trace of previous electron paths for eternity. The new current can go in either direction depending on the pathway. Given a pathway of less resistance it will travel that way to it's newly biased ground. That includes an opposite direction. There is no force tendency of any kind at work on the new current from the old current. That's just superstition.

[Magluvin]

just tried on circuit sim. The reverse charge on the cap feeds back to primary. So we end up with a alternating oscillation. Unless the timing of the proceeding spikes are at the point where the cap is in full reverse charge before it is fed back to the pri.  Just solid state at the moment to get the hang of it  Will play with it more to see what I can do to fix that.  Love that sim for times like this. Real time saver on simple stuff.

Mags

[MileHigh]

I will try to finish off the measurement discussion....

The only thing left to do is look at the capacitor discharging through the secondary coil.  I agree with Gyula that changing the resistor at position #4 from one ohm to 10 ohms would be a good idea.  When you look at Laurent's existing scope shots at position #4 you see a linearly decreasing ramp of current flow.  That looks just like a resistor.  That would suggest that the 210-ohm resistance of the coil is dominating over the inductance, but I am not sure how much secondary coil pulse energy will be imparted onto the rotor.  The measurements and the number crunching should give us a handle on that.

I am going to assume a quality multimeter or Laurent's scope will give an accurate measurement for the RMS voltage across a 10-ohm CVR at position #4.  When in doubt, do the research yourself to check these things otherwise you might be a victim of GIGO.

This time I am not going to give a description because it would just be a repeat of what was stated for other components.

Here are the new measurements:

L - RMS current through 10-ohm resistor at position #4
M - Average power dissipated in the resistance of the secondary coil
N - Pulse energy dissipated in the resistance of the secondary coil ([M]/[F])
O - Secondary coil pulse energy that is imparted onto the rotor  ([J]-[N])

Here is the whole measurement shebang with the more interesting stuff highlighted.  Some of the measurements are derived from other measurements, and you can easily determine other efficiency metrics, etc.

A - Average input current for entire circuit
B - RMS current through the drive coil
C - Power dissipation in the resistance of the drive coil
D - Average input power
E - Exported power from the drive coil, ([D] - [C])
F - Pulse frequency
G - Input pulse energy ([D]/[F])
H - Exported pulse energy from the drive coil ([E]/[F])
I - Maximum voltage across the 1 uF capacitor
J - Maximum energy in the 1 uF capacitor
K - Main drive coil pulse energy that is imparted onto the rotor ([H]-[J])
L - RMS current throuugh 10-ohm resistor at position #4
M - Average power dissipated in the resistance of the secondary coil
N - Pulse energy dissipated in the resistance of the secondary coil ([M]/[F])
O - Secondary coil pulse energy that is imparted onto the rotor  ([J]-[N])
P - Percentage of input pulse energy that becomes resistive losses (([C]/[F] + [M}) /[G]) * 100
Q - Percentage efficiency (total rotor pulse energy/input pulse energy) * 100 == (([K]+

• )/[G]) * 100[/b]
  R - Ratio of secondary coil pulse energy imparted to rotor to drive coil pulse energy imparted to rotor
• /[K]