Double Pendulum Power

[vince]

Hi Telecom


You will see in my notes that voltage and amperage were measured at the ac input line to PWM ( pulse width modulator).  The voltage will remains the same at this point.  After it goes thru the PWM,  power is pulsed to the motor to vary the speed, Hence PWM. Read up on PWM and you will understand better.


Vince

[gyulasun]

...
Do you have any thoughts on a possible generator for the system? You mention a dc motor but if it is a brushed motor it would only utilize a few bars of the commutator and their respective coils. A PM motor would be better but can it generate any real power with such little movement even though the frequency would be high. Im not sure how a conventional ac generator would react?

Hi Vince,

I think that converting the oscillating movements into a rotary motion would solve the generator question?  Crankshafts like used in old steam machines?  and the wheel rotated by the crankshaft(s) would serve as a flywheel too and could surely drive a normal generator or alternator.

Thanks for all the measurements efforts!

Gyula

[vince]

Hi Gyula
That was my first thought but several problems arise .  First the stroke is to short to make any usable rotary motion . Levers a could be used to increase stroke but that adds complexity and drag. The other problem is the stroke gets shorter with loading which would never work with a crankshaft.
What do you think of a magnet or an electro magnet positioned over a core with a coil . It could be made to reciprocate with the pendulum and induce a current in the coil. I don't know how much movement would be required to have induction occur though.


Vince

[gyulasun]

Hi Gyula
That was my first thought but several problems arise .  First the stroke is to short to make any usable rotary motion . Levers a could be used to increase stroke but that adds complexity and drag. The other problem is the stroke gets shorter with loading which would never work with a crankshaft.
What do you think of a magnet or an electro magnet positioned over a core with a coil . It could be made to reciprocate with the pendulum and induce a current in the coil. I don't know how much movement would be required to have induction occur though.


Vince

Yes if the strokes are too short then no cranshaft-like convertion is practical. 

Veljko Milkovic has shown some conception on the coil - magnet induction, to utilize his two stage mechanical oscillator, the magnets could be moved by the strokes, see here:
http://www.youtube.com/watch?v=h4Do_dTI_Ow       from this link:  http://www.pendulum-lever.com/applications.html 

Even a small 1cm long displacement (stroke) can induce useful power, it mainly depends on the strength of the magnets.

Gyula

[telecom]

Hi Telecom


You will see in my notes that voltage and amperage were measured at the ac input line to PWM ( pulse width modulator).  The voltage will remains the same at this point.  After it goes thru the PWM,  power is pulsed to the motor to vary the speed, Hence PWM. Read up on PWM and you will understand better.


Vince

Hi Vince,
the reason I asked the question is because the power consumption is too high based on your data, in particular for driving the pulley alone.
Either it wasn't measured correctly or some bearings are jammed.
I suggest to take a fish scale and measure the actual turning torque .