Self accelerating reed switch magnet spinner.

[conradelektro]

@Conradelektro,


                        Too big a coil face will create Lenz drag. You won't want too many wraps thick. Keep in mind where the power's coming from. Skycollection uses those big pancakes with the ferrite electromagnetic toroid cores. He only partially minimizes his Lenz drag as a consequence. I wouldn't raise the face more the 1/2", which would make 1" total for drag face. 1/4" might even be better. Thin wire will yield lots of turns due to the length of the coil, so thickness is less of a priority. A 3/8" thick radius would probably be plenty depending on wire gauge. Plenty of turns due to coil length and wire thinness is going to raise the output voltage pretty high, so I wouldn't recommend over winding. The form looks perfect. Very nice work.

@synchro1: thank you for the coil face hint, will try to follow up.

Attached please find an updated drive circuit which switches just perfectly (see the scop shots, probe 1 and probe 2), 9 V, 1.1 mA , ~ 10 mW, ~1200 rpm.

Without the 100pF cap (base to GND) there was a little oscillation when switching off, which is now gone (the 22K are also better than the 100K from base to GND).

Let's see what we can generate with the synchro-coil, I am looking forward to the first tests. Unfortunately it is not the best time of the year to go into this. So, be patient. At the beginning of the new year I will be able to concentrate better.

Greetings, Conrad

[conradelektro]

@synchro1:

Does the attached drawing show a "Tesla bifilar" coil winding according to your specification? Just to make sure that I get it right?

Greetings, Conrad

[synchro1]

@Conradelektro,


                       That's the correct connection. "Zero reluctance to change in current direction". A single wrap would generate waste heat from the oscillatory excitation.

[synchro1]

Attached please see the circuit for the first measurements I intend to do with the synchro coil near my vertical magnet spinner. It will be held by hand (resting on the base plate of the spinner).

The intention is to get a first indication of its output power.

Is the 10µF capacitor too high if one expects a few mA?

Greetings, Conrad

I think you're ten times too low on your output estimate. I predict you'll generate micro amps, and I would step your capacitance up to 50v 100uF if possible. The amount of output power is going to shock you. Be prepared for a surprise. It should only take a few minutes to top the capacitor off in that elevated range. I'm not fooling around. Brace yourself to soar way overunity when you start to feel that shudder in the magnet core!


Imagine how many times the magnet core field shifts per rotor revolution from the saw tooth pattern of the zone polarity change, compared to the speed it would take to do it from the rotor? The rotor speed might have to be 15,000 r.p.m. to do what 1,500 rpm would do with ten zone shifts per turn.  

[TinselKoala]

@Conradelektro,


                       That's the correct connection. "Zero reluctance to change in current direction". A single wrap would generate waste heat from the oscillatory excitation.

I think we've been here before. Would you please explain just what the highlighted phrase means, in commonly understood electrical engineering terms?