Has anyone seen Lasersabers new motor runs on 1000uf cap

[gyulasun]

...
I made this bifi coil with 26awg a couple weeks ago. Testing it I found very interesting results.

Measuring 1 of the 2 conductors measures 7mh. Same with the other.  When I put them in parallel it measures 7mh. I wonder if one of those windings were say fishing line, non inductive, would the single winding still read 7mh? Like does the simple presence of the other non connected winding affect the result of measuring the other alone.

Then in series it measures 27mh.  Its bifi, so may not be correct.


Tested it multiple times to be sure.

Ok I think I get what your saying on the freq of the meter.  I measured the freq without an inductor connected. 

200uh scale     786hz
2m   20m   200m  2h    217hz
20h  for some reason reads 222hz

Mags

Hi Mags,

Nice instrument you bought, thanks for showing it, my curiosity is satisfied...   

On your bifilar coil, you wrote: "When I put them in parallel it measures 7mh. "  If you mean you connect the two start wires together and also the end wires together and you measure 7 mH, then it is CORRECT.  Why? Because all you have done you increased the cross section area of the wires by paralleling them: the same effect as if you were wound the coil with an equivalent thicker SINGLE wire, ok? 
And yes if one of those windings were from fishing line, the other single winding would still read 7 mH.  The simple presence of the other non connected winding normally does not affect the result of measuring the other winding alone. 

You wrote: "Then in series it measures 27mh.  Its bifi, so may not be correct."  It is CORRECT. Due to the mutual inductance between the closely spaced parallel wires, the result in such series aiding connection can be 4 times of any of the single coils inductance alone (the 4 times is in theory, in practice I measured 3.7 to 3.9 times or so increase in inductance).

Thanks for the the measuring frequencies in the L ranges, they are good to know, especially when measuring very high inductance coils which normally was not intended for  'high frequency' operation and checking them at a higher than intended frequency by just your meter it may display L values which are not true at a lower frequency.
In your 20 H range you may wish to see the measuring waveform and its frequency by an oscilloscope too, either without any coil and then with a high L coil like a mains transformer's primary. 

Gyula

[gyulasun]

Here is a pic of the test leads shorted in uh scale.  I made a mistake in my last post. .1uh not .01uh

Mags

Well, normally it should display zero when the input is shorted but this is not a high end instrument. MAybe somewhere inside there is a trimpot to set display to 0.00 when shorting the test leads, otherwise you would have to distract 1.2 uH from a displayed value of say 4 uH (because it displays a negative 1.2 uH).  Of course I do not suggest to turn any trimpot inside unless you obtain a service manual if such exists. 

Gyula

[Magluvin]

Well, normally it should display zero when the input is shorted but this is not a high end instrument. MAybe somewhere inside there is a trimpot to set display to 0.00 when shorting the test leads, otherwise you would have to distract 1.2 uH from a displayed value of say 4 uH (because it displays a negative 1.2 uH).  Of course I do not suggest to turn any trimpot inside unless you obtain a service manual if such exists. 

Gyula

Well the manual said to put the leads of the device to be measured directly in the terminal holes. I can imagine that with larger inductances, the addition of the test leads, which are short, add a tiny bit.  Im just happy to get in the ball park really. 

Havnt had time to do much today. Got to get to it in a bit. Making dinner.

Mags

[Magluvin]

Finally got some time to work on this. Got the rotor drilled out for mags and Im winding a coil on the rotor for other tests I want to do while Im at it. The winding in the pics is the first of 2, and the second winding will have many more turns. Just to have 2 variations to test.

Will be wiring things up this week. Pondering what to use as terminal posts. Have some bare copper wire from Ace Hdwr.

Mags

[Electrogasman]

Gotta Love that guy for pouring out his heart on experiments with motors.

I have many joule ringers.


Maybe I will make this motor? I quess I am to late to see the diagram but will look around for it.