Quote from: MasterPlaster on June 16, 2011, 03:38:24 PM
@ben
I have been an admirer of your work for a long time. I would lke to point out that the DVMs are not generally designed for the kind of measurements we subject them to and whilst I am wishing you good results, perhaps better techniques should be used to disperse any false indications.

Many regards

Hi MP,

Next video will try to cover your concerns.  As I am only showing filtered DC, mearsurments are fairly accurate but can absolutely
be documented better next time.  Thank you for your observations and concerns.

Respectfully
Ben K4ZEP

New question on coil core materials, I need assistance, advice, clarification on before I do a LOT of work making mu-metal cores.

I have 10+ kg of mu-metal plates off of old hard-drive magnets I've collected over the past 2 years. I want to melt and cast 18 to 20 mm diameter rods and use this as the core materials for my next coils (will cut coil ends and have coils approx. 25mm in length). What can I expect (coil characteristics) using this material vs. the 18 mm dia. hollow ferrite tubes I am using now?

Would you use mu-metal cores with wire wrapped directly to them IF you had them? Looking for yor advice and opinions.

The old shop tchr [39 yrs] trying new things. [Today was LAST DAY for my students so now I can do what I want       for the summer!]

Quote from: tinu on June 16, 2011, 04:52:22 PMI suspect the behavior, which I admit is mind puzzling

Nothing puzzling there. Smells like power factor correction. Watch amp draw on PSU.

03:08 0.07A "boost" hi rpm
05:43 0.03A "no boost" low rpm
06:09 0.07A "boost" hi rpm

It does not mean it is wrong direction to go, however. It does mean that devil is in the details

Quote from: tinu on June 16, 2011, 04:52:22 PM
Hi Ben,

I suspect the behavior, which I admit is mind puzzling, is due to the regulated PS. I explain it:

http://www.youtube.com/watch?v=zrj4Lq9I_6c

When rotor at rest, the PS is loading the 68mF cap in reverse polarity, up to a -.363V (when equilibrium is reached). For that equilibrium, PS delivers about 5mA which is ok. IMHO you do not “leak voltage” and all voltmeters work fine. PS built-in voltmeter fluctuates in between 14.4 and 14.3 so I’ll take 14.35V. And 14.35 +(-.363) gives exactly what you read on the “more accurate one”, namely 13.9V. So everything is clear to me so far. Agree?

Further, you kick the rotor on and experiment begins. The same 68mF starts charging. Puzzling!!!

I believe that, most probably, the PS has a significantly lower filtering cap, maybe 10mF (please confirm). If so, 68/10=6.8 and the back EMF from motor coils is largely felt by the PS and not by the 68mF cap which act as a short at that frequency. The regulated PS when detecting a decrease in voltage, tries compensating that by pulsing up the current, hence more power delivered to the motor coils.
On the other hand, a resistor placed instead of 68mF would take most part of the back EMF voltage on it (series circuit -> voltage divider as per impedance ratio) so the PS will act very differently.

Please comment. (I apologize for leaving the forum now but it’s late in the night here.)

Respectfully,
Tinu

Hi Tinu,

I have respected your work and comments on this list over time and thank you for your very astute observations.  I will try to show this effect and how it effects this this motor/gen. ASAP but this takes time.  Absolute proof of any claim requires absolute bulletproof undeniable date to back it up.  Will take a while to document.

Again thanks for your observations. 

Respectfully
Ben K4ZEP

Quote from: yssuraxu_697 on June 16, 2011, 06:30:08 PM
Nothing puzzling there. Smells like power factor correction. Watch amp draw on PSU.

03:08 0.07A "boost" hi rpm
05:43 0.03A "no boost" low rpm
06:09 0.07A "boost" hi rpm

It does not mean it is wrong direction to go, however.

Hi "YS"

A very astute observation, Something else to check and verify!!!!!
I appreciate all the input from some great input out there!
Will try and get a handle on all the ideas and observations.

Respectfully
Ben K4ZEP