huge dc voltage drop

MaxHeadRoom

Joined Jul 18, 2013
28,617
Check out some of the Utube vid and articles on converting Fisher-Paykel out-runner type of motor, They are used as (rectified) 3ph wind generators.
A better idea than making it is to look for a scrap machine and use the motor.
Max.
 

vu2nan

Joined Sep 11, 2014
345
Here's my take.

It appears that the stator in question is part of a homemade alternator for a windmill generator.

The starts of all coils are connected to a floating 'ring neutral'. The ends of consecutive pairs of coils are connected to the input of a bridge rectifier. Effectively, every bridge rectifier is fed by a pair of adjacent coils connected in series. The 'ring neutral' has been used only for convenience, instead of shorting links for each pair. The coils may appear to be connected in series opposition but they are not, taking into consideration that consecutive magnet poles on the rotor would alternate. The bridge rectifiers then feed a common DC bus.

The circuit configuration is analogous to a number of power supplies, having centre tapped transformer secondaries and bridge rectifiers, feeding a common DC bus. Connecting the centre taps to a common floating bus would not alter the functioning.

Overloading or a problem with the booster may be a likely cause of the voltage drop.

Regards,

Nandu.
 
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MisterBill2

Joined Jan 23, 2018
18,167
Check out some of the Utube vid and articles on converting Fisher-Paykel out-runner type of motor, They are used as (rectified) 3ph wind generators.
A better idea than making it is to look for a scrap machine and use the motor.
Max.
A still better idea would be to rewind a used automotive alternator to generate a lot more voltage but at a lower speed. Less current of course, but probably the unknown application needs less current. And of course the added benefit that all of the windings would be producing current for the whole rotation.

The rewound alternator could be used with or without the diodes so either AC or DC could be used.AND rewinding an alternator would be much easier and simpler then rewinding a motor.
 

vu2nan

Joined Sep 11, 2014
345
A still better idea would be to rewind a used automotive alternator to generate a lot more voltage but at a lower speed. Less current of course, but probably the unknown application needs less current. And of course the added benefit that all of the windings would be producing current for the whole rotation.

The rewound alternator could be used with or without the diodes so either AC or DC could be used.AND rewinding an alternator would be much easier and simpler then rewinding a motor.
Hi MisterBill2,

All the coils would generate for the whole rotation in the present setup too since the rotor would have as many magnetic poles as the stator has coils!

Regards,

Nandu.
 
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MaxHeadRoom

Joined Jul 18, 2013
28,617
A still better idea would be to rewind a used automotive alternator to generate a lot more voltage but at a lower speed. Less current of course, but probably the unknown application needs less current. And of course the added benefit that all of the windings would be producing current for the whole rotation.

The rewound alternator could be used with or without the diodes so either AC or DC could be used.AND rewinding an alternator would be much easier and simpler then rewinding a motor.
No rewinding with the Fisher-Paykel!
Max.
 

MisterBill2

Joined Jan 23, 2018
18,167
No rewinding with the Fisher-Paykel!
Max.
I am not familiar with the Fisher-Paykel! product. And the device under discussion has a limited capability. Here follows the description: "There 18 homemade coils. Each coil has 725 turns of wire at 28awg. of course, there is an array of magnets rotating super close to the coils to induce current/volts. if this helps. "
just rearranging them in series-aiding will improve the output power by boosting the voltage while not reducing the current. Of course, that depends on the phase relationship of the coils. If they are uniformly spaced then three groups of six in series may provide quite a bit more power if it is to be rectified. For a simpler AC output, possibly two groups of 9 in series. It is dependent on the number of magnets that are rotating, and how they are spaced.
But always, generator coils are put in series-boosting arrangements.
We need to know the number of magnets that are rotating to be able to see what arrangement will be the most effective.
 

shortbus

Joined Sep 30, 2009
10,045
We need to know the number of magnets that are rotating to be able to see what arrangement will be the most effective.
Late to the game but that would be my question too. That and what are the coils wound on,the drawing shows no pole pieces, air pole coils don't generate as much as ones with ferric pole pieces. The drawing makes it look like it is an axial generator and they really need pole pieces.
 

MisterBill2

Joined Jan 23, 2018
18,167
Getting back to whatever device the TS has, the number of magnets matters a whole lot as far as the best arrangement for a series connection oof the coils. That is at least part of the reason that the output is so poor. OF COURSE, we did not really get any information as to how fast it was rotated.
 
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