Muller Dynamo

[mondrasek]

Thought I would share this correspondence from MileHigh.  It explained many different things to me.  Hopefully others can benefit from it as well:

Quote:

>>> AC ripple on top measures maximum of 6mV p2p. This was with a load and RPM setting that was providing 8.08 Vout and 7.17 mAout to the load.<<<

Good on you for making the measurement. It's a critical measurement and should be made all the time as you change the load configuration. As you lower the value of the load resistance you will see that the voltage waveform gets more and more ripple in it.

Back to your measurement where the voltage is nearly DC. What's that telling you?

It's telling you that the cap has more than enough storage capacity to discharge into the load resistor before the next "fill up" from a generator coil pair happens. It's also telling you that in this particular example the load resistor is not dissipating that much power in the grand scheme of things because it's not lowering the voltage on the capacitor significantly. When you see the gentle rise in the output voltage waveform that's when the generator coil is pumping current (and energy) into the cap.

We are so close to the question I asked you that we will follow it through.

Assume one pair of coils and the load resistor is dissipating 10 units of energy over a certain time interval as the motor turns. We will use abstract units to keep it simple.

If the resistor is dissipating 10 units of energy then the coil pair is pumping 10 units of energy into the capacitor + resistor. In other words, for every "fill up" or "topping off of the tank" 10 units of energy are being pumped into the capacitor + resistor.

So, you added a second pair of generator coils and almost nothing changed. Why?

The answer is simple. Now you have two coil pairs pumping energy. Now each coil pair does a "fill up" but the load resistance hasn't changed. If the load resistance hasn't changed then it's not going to try to suck more energy, it will suck approximately the same amount of energy if the voltage on the cap is about the same.

We are assuming that the two coil pairs are matched and output the same voltage waveform.

So you went from one "fill up" per cycle to two "fill ups" per cycle. That means that each coil pair will pump five units of energy into the cap + resistor per cycle.

When you add an additional coil pair they now SHARE the workload to keep current flowing through the load resistor. If the resistor discharges 10 units of energy per cycle each coil pair contributes five units of energy each.

It feels to me like you and most of the rest of the group where just blindly assuming that when you add an extra generator coil pair the power output would double. It's not the case, the power that originally provided by a single coil pair is now split between two coil pairs.

So simple and sensible, don't you think? Did I see you post spreadsheet cells where you make measurements for one generator coil pair and then extrapolate what the numbers would be if you had nine generator coil pairs and you see preliminary numbers that show over unity? Well, you now hopefully understand that those extrapolations are nonsense. (for two reasons, as you will see below)

So how do you get twice the output power when you add a second coil pair? Part of the answer is that at the same time you have to LOWER the value of your load resistor to burn off twice the amount of power. Doing that will cause more Lenz drag on the motor, which will lower the voltage output from the two pairs of generator coils. If the output voltage lowers, that means you will have to lower the value of your load resistor even more in an attempt to get twice the power out. Now the light bulb load seems pretty useless don't you think?

When you do all of this you can't forget the other "wall" that you are up against. The other wall is that the pulse motor driving the motor (in your case I think you have a DC motor but let me just talk about a pulse motor) pumps a FINITE amount of mechanical power into the rotor.

That goes right back to your crazy extrapolations where you multiply everything by nine to imagine what kind of output you can get with nine output coil pairs. You are forgetting the fact that on the "drive side" the pulse motor supplies a finite amount of mechanical power to turn the rotor.

That means relative to the "drive side" your output coil pairs are also SHARING the available drive side power.

Now perhaps you understand your motor more than you ever did.

MileHigh

End quote.

M.

PS.  These comments from MH are directed at my current "classical generator" type build only!  Those that may be testing other configurations need not pay attention to them, imho.

[mondrasek]

I went ahead and performed a test with one coil pair to a given load, and then two coil pairs in parallel to double the load (1/2 the resistance) per MH's explanation.  The results do not look promising.

[plengo]

I did a test today where I would short the output cross the buffer cap (cross the load) and I noticed that I can double the amount of current without affecting the output voltage and very minimal impact on total RPM.

I am shorting the cap at around 20 times each with a duration of 100 microseconds.

Fausto.

[plengo]

Fuasto, if you don't mind me asking, in what part of the world do you live?  I just realized that your postings do not appear to follow my own normal awake hours.

Australia?

I am close Boston in Massachusetts in USA. I am originally from Brasil but I live here for about 20 years.

Fausto.

[xenomorphlabs]

I did a test today where I would short the output cross the buffer cap (cross the load) and I noticed that I can double the amount of current without affecting the output voltage and very minimal impact on total RPM.

I am shorting the cap at around 20 times each with a duration of 100 microseconds.

Fausto.

Just to be sure, you are actually shorting the DC o/p cap BEHIND the FWBR and the cap voltage does not get affected at all and the current to the load doubles ? You shorted manually?
That's actually the 2 stage extraction strategy that Doug has developed, where he would do it non-reflective to the source with MOSFETs.