Self accelerating reed switch magnet spinner.

[synchro1]

Here's the video of Jonnydavro's unit: The vertical axis design looks great!


https://www.youtube.com/watch?v=eggfplU7Abw


Jonnydavro's vertical axis:


https://www.youtube.com/watch?v=hZbscMyotJg

[Pirate88179]

Conrad:

That is a really nice build you have there.  I wish I had some thoughts to possibly add to it but I don't at this time.  Really nice job.  Do check out Jonnydavro's work, he has some interesting designs for sure.

Bill

[conradelektro]

@synchro1 & Pirate88179:

I really like the designs from jonnydavro, specially the vertical spinner is a great idea. Thank you for pointing me to jonnydavro's videos. Just what I needed.

Fortunatelly I have got some ball magnets.

Greetings, Conrad

[conradelektro]

I built a little vertical model with a 3 mm axis. There also is interaction between the spinning diametrically magnetised magnet and the suspension magnets (axiall magnetised ring magnets). But it is not very strong although the spinning magnet is quite powerful. The axis turns up to a minute after being started by hand.

See the photos, two little models (vertical and horizontal axis) are now ready to be driven by some electronics. I want to do it with a comparator.

Once I gain some experience with the drive electronics (which could make changes in the design necessary) I might build bigger models with a 5 mm axis.

Greetings, Conrad

[conradelektro]

At the first attempt I could achieve about 13 mW and then 10 mW power draw to spin the little horizontal model at about 3000 rpm.

Power draw:  4 Volt at 3.2 mA  and then 3.6 V at 3 mA

The LM311 circuit is not very good yet, just a quick try. (Do not replicate it.)  Also the position of the coils is not yet optimal. And the LM311 is a power hog.

At the moment I am using a drive coil with iron core and a DC resistance of about 280 Ohm. The next attempt will be to use the same type of coil for triggering and for driving, namely a coil without core and a DC resistance of about 1 K. Finally I will replace the LM311 with the MAX931 which needs a fraction of the power. I also want to try AC coupling of the trigger coil, which should dampen oscillations of the comparator.

I do all the testing with the LM311 because it is cheap (do not mind damaging a few). The more expensive MAX931 comes in when everything is a bit under control.

As it looks now, I can bring down the power demand well below 10 mW. But it will have to wait a few days.

Greetings, Conrad