Cct for pulsing F&P motor
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RossW
Guru
Joined: 25/02/2006
Location: AustraliaPosts: 495
Posted: 01:52am 12 Mar 2006
brucedownunder2 said
Tried that --no luck , it moves the blades a very small distance -maybe a pole on the stator(like we think should happen) , but thats about it . and the more u do it the less it becomes-maybe gets saturated ?. </QUOTE]
That's entirely what I expected. I think it's not saturating, but rather as the magnets move, they get closer and closer to the coil you're energising - thus, they can't move much closer!
Quote
Tried the "motoring one with another " no movement at all-.
Feared that might be the case, just not enough "power" at low rpms, and if you spin it quicky, the prop wont be able to get started because the field will be moving too quickly for it.
Here are two more dodgy circuits for you then:
The first should create a "moving" field from one pole to the next.
This second one will pull then push, so once your magnets are aligned with the magnetic field (as you found on the first one), flipping the switch to the OTHER side will create a replusive force now, and should push the magnets away from the coil.
It's still not going to create a rotating magnetic field though, this was only ever a simple "bump" circuit.
If you have a small VFD (variable-frequency drive), often found on machines with (proper) speed controls on AC motors, you could unplug the machine from your charger and into the VFD and give it a tickle that way. It would produce the rotating magnetic field you need, both positive and negative cycles with the proper phase relationship.
What I've drawn above is very rude, crude and unattractive. As I said, it was just something to give a bit of a "bump". If the mill requires more than that, we may have to get significantly more complex to synthesise something closer to the mark.
Oh, the 555 idea would probably work, but if a single pole isn't enough to get your mill away by hand, there's no point even trying the 555 to limit pulse width or current.
RossW
