Body
PM dc motors can be rewired to WYE from its customary DELTA wiring and a second set of brushes used to Recover the reverse pulse into a capacitor across a diode bridge. simply you cut one wire segments from the brushes that have 2 wires in delta in one direction and solder into a wire ring ( any number of brushes )
with no self shunting will work ou ..... at X speed (sweet spot)
not the first time i post this , and still no one had commented on it ....
its so fucking simple to experiment with a dc 12v car PM dc motor .
the hardest part will be to place extra set of collector brushes but is not so hard as building
a wachumacallit little school brat toy motor !
(H)
PS why not stop going back to the bullshit toys ?
---In [email protected], <schoonersolsticemoon@...> wrote :
Doug If we are experimenting to find a speed, nothing is easier than a dc motor run by a variac.
Once the magic sweet rpm is found, it is fairly simple to note that rpm and then with pulleys and belts use a fixed rpm ac motor.
Now my question concerns the RV running as a motor. It takes a certain horse power to turn the generator shaft at a speed, even without a load on the generator, and friction with belts and pulleys.
What I am curious about is delivering that specific load, with whatever device, and comparing an RV driving that load at a certain draw, and for instance a permanent magnet motor draw for that same load, comparing them with numbers indicating relative efficiencies.
I told you how I have run my drill press on the boat using 12 volts and a weenie 300 watt inverter that I have never blown the breaker on, even drilling 1" holes in stainless plate! The little belt on the drill press may slip, but that motor doesn't even know there is a load , hardly.
It is a very practical system to use involving a 5 amp Variac run by the 300 watt inverter (120 v 60hz) and a bridge rectifier, a double pole, double throw, switch, and to the motor.
I change the speeds with either the belt, or the knob on the Variac, using the drill press for everything from router, using carbide cutters, for aluminium, or teak, using vertical milling cutters, and cross slide vise for cast iron machining, high speeds with wire brushes for polishing metal, or grinding with grind stones, rotary files etc.
Oh, and I also drill holes with it.
300 watts does it just fine for everything, using a cheap Taiwanese cast iron drill press, that was under $100, with the ac motor changed for a permanent magnet Dayton 5/8" shaft ordinary dc motor of perhaps 90 volts nominal used for computer tape drives, and bought for scrap.
I have lots of unemployed RV motors too.
I am curious to get this right, and sort out what is making the magic.
Cheers Warren
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On Tue, 22 Jan 2019 at 7:34 AM, konehead@... [EVGRAY]
<[email protected]> wrote:
Hi Warren
Not trying to confuse., just saying any sort of prime mover motor could be used IF your generators are no lenz.....
Rotovertor is stuck in its sinewave speed so would need a VFD to test the generators at specific rpms that will give the delayed Lenz effect.
Why this design loops and with power left over is the generators are turned by belts and pulleys that put them into that delayed Lenz effect rpm window.
To find that rpm window you need to run the generators through wide rpm range until you find through the testing where amps drop low while generator is under load noe.keep rpm steady there, and loop it...msybe rpms drops some when you try and loop it, so if so, go for higher rpm initially and let the rpms drop into the delayed Lenz effect window zone...this I believe why the flywheel. As Gary said original builder said he looped it without flywheel and flywheel only makes it easier to ":introduce" the load.
As for rotovertor shsft power, you must increase run cap uf to give the shaft some decent torque....the original lowest draw run cap value at idle with no load on shaft will stall the shaft very easy with just light load on shaft so you need to increase run cap uf when turning loads...i found about 30uf gave me good power not so much extra draw with 7.5hp baldor as example. Be careful introducing large caps while motor runs!!! You might/will need to shut down motor and restart with new larger uf run cap in place
already, so use start cap to get it going from stop, and pull off start cap leaving just the new larger size if run cap.....try putting a 30uf cap on your rv motor as it runs very very briefly you will see lots of magnetic braking manifest...
Kone