Has anyone seen Lasersabers new motor runs on 1000uf cap

[wattsup]

@all

Hmmmmmm. I managed to install the Autodesk 123D Design but when I go to open an existing file, it does not recognize @LaserSabers *.stl files. I guess that means I will have to draw my own or just go with the files @LS put up and have the parts printed in via a local 3D print guy. Rats.

wattsup

[gyulasun]

Hi Wattsup,

Normally the newer versions within a design software are made to downward compatible with the older version's files but in case LS say uses an old enough version and then later the newer versions went through some significant developments than it may not be valid any more.  So by knowing the version number of LS's Autodesk (its exact name too) and then studying the records of the version modifications on the Autodesk site may reveal something.

Gyula

[lumen]

STL files are not the best format for transfer of 3d cad data, these are mainly for 3d printing.
A better format for use with CNC machines would be SAT or even the old IGES format.

[conradelektro]

I did some tests with my 6 coil pulse motor (replication of Lasersabers's first 3D-printed pulse motor):

See my YouTube video https://www.youtube.com/watch?v=rFvstgIRuOA (best viewed with 720p)

The two most important circuits are added. The aim of the tests was "charging a 1000 µF electrolytic capacitor" by blowing air over the rim of the rotor in order to turn it into a generator.

Note: the cap is charged up from 0 Volt (no battery and no power supply used, no initial charge, may be a residual charge of about 5 mV).

Astonishing, when shortening the coils with a Reed switch the cap could be charged to a higher Voltage (2 Volt without a Reed switch, 4 Volt with a Reed switch shortening the coils).

My next test will be a double Reed switch in order to limit the ON-time of the Reed switch combination. But I still have to build the adjustable double Reed switch. The double Reed switch idea was suggested by Gyulasun. I will also try to adjust the ON-time of the Reed switch with a magnet behind the Reed switch as suggested by TinselKoala.

Greetings, Conrad

[gyulasun]

Hi Conrad,

It is very good you got back home safe and sound escaping from the huge flooding raging in Central Europe. 

Very good tests!  I am trying to find explanation on the double DC voltage received in generator mode with using the reed switch. 

(I assume you tried to keep the rotor speed more or less the same in both cases i.e. without and with the reed switch, right?  Also what you wrote:  "Astonishing, when shortening the coils with a Reed switch the cap could be charged to a higher Voltage (2 Volt without a Reed switch, 4 Volt with a Reed switch shortening the coils."  this means the reed switch was actually in series with the coils as the schematic shows and NOT shorting the coils, right?).

With these two assumptions,  I think when the reed switches OFF, the voltage spike across the series coils charges up either the reed switch self capacitance (a few pF with the wireing) or the optional parallel cap (you drew 100 nF) and this charged up capacitor behaves as a voltage source (with higher voltage amplitude than the 1000 uF has) hence its charge goes into the 1000 uF via the coils and the diode.  This could be checked by connecting a scope probe in parallel with the reed switch (probe ground clip to 1000 uF negative line) and 'air-blow up' the rotor to the speed where the 4V DC is received in the 1000 uF.
Earlier I tended to accept that in LaserSaber's setup the germanium diode conducted backwards (Ge diodes indeed have a few uA reverse current) so the spike's was able to drive charging current backwards via the diode into the 10 or 1000 uF cap but now that you have used Silicon diode, this may not fully be the explanation.  Si diodes have pico or nanoAmper reverse current. 
If the scope shows a positive spike-like pulse format across the reed switch when the reed is just off, then you may try to use different capacitor values in parallel to find the best value which can give the highest DC value in the 1000 uF. When first chacking the waveform across the reed with the scope probe, do not use the 100 nF in parallel with the reed, probe will add 15 pF in parallel with the reed's self cap.)

Thanks,  Gyula