Circuit setups for pulse motors

[capthook]

Tropes -
Thank you for the info and the circuit diagram!!  A picture is worth 1,000 words!

With power losses/consumption of the switching method being the primary concern - I have to agree with casman - a reed switch is going to offer the best solution.  I want optical - would like Hall - but I can't stomach the losses!!  I guess sometimes a club (low-tech) is better than a cannon.

CH

[capthook]

What?s the best/most efficient/least losses way to rectify a 3-phase, Y-configured AC output to DC battery?

I?m trying to finalize my circuit/wiring for my low RPM ? low voltage motor/generator.  I plan on using three-phase, Y-configured wiring for my output so that voltage adds.  This is the way to go ? yes?
From there ? I need to rectify.

An aspect of most rectification is a loss from peak input voltage to the peak output voltage, caused by the built-in voltage of the diodes (around 0.7 V for ordinary silicon p-n-junction diodes and 0.3 V for Schottky diodes).

Bridge rectification for three-phase AC will have a loss of three diode drops. This may represent significant power loss in very low voltage supplies.

And what if I wanted to implement a voltage-doubling rectifier?

What is the best rectifying circuit solution to provide the lowest drop?  Schottky ? MOSFET ? SCR ? Germanium etc??.?

I understand Schottky setup (like picture below)? clueless on aspects of the others??.
It sounds like MOSFET will further reduce voltage drop? (eliminate .9v diode drop)
How to use MOSFET if so??

CH

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Info compiled from the web:

Instead of using a readily-made rectifier, use 6 schottky diodes 1N5818. This way you reduce the voltage drop in the rectifier from 3 x 0.7 = 2.1 V to 3 x 0.3 = 0.9 V

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Metal-Oxide Semiconductor, Field-Effect Transistor
In recent years semiconductor synchronous rectifiers have been designed; using MOSFET transistors, they can also rectify with a very low forward voltage drop and have the additional advantage of being able to switch at extremely high speeds. Semiconductor synchronous rectifiers are now widely used in those electronic power supply units designed for very low output voltages (where the voltage drop in an ordinary rectifier would represent an unacceptable fraction of the total output voltage).

The synchronous rectification is a technique for improving efficiency of power converters in power electronics. It consists of connecting a diode and a transistor (usually a power MOSFET) in parallel. When the diode is forward-biased, the transistor is turned on, to reduce the voltage drop. When the diode is reverse-biased, the transistor is turned off, so no charge can flow through the circuit. This way, a rectifying characteristic is obtained, without the forward voltage drop associated with diodes in the on-state.

Paralleling two MOSFETs reduces the losses further, whereas paralleling several diodes won't modify their threshold voltage.
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[tropes]

Tropes -
Thank you for the info and the circuit diagram!!  A picture is worth 1,000 words!

With power losses/consumption of the switching method being the primary concern - I have to agree with casman - a reed switch is going to offer the best solution.  I want optical - would like Hall - but I can't stomach the losses!!  I guess sometimes a club (low-tech) is better than a cannon.

CH

CH
I'm glad to hear you have found the best solution for your set-up. It took me years going from Star commutator to Reed switch to Hall IC to Optointerrupter.
Tropes

[hoptoad]

There are still losses in the reed switch which are photonic, acoustic, and mechanical.

But IMHO, the small plasma arc that is created in both a reed switch and a star commutator, or any other mechanical contact arrangement, is the real curiosity here.

Classic theory states there are always losses. Yet Tesla began his lifelong pursuit of tapping "that great energy" after studying the sparks produced by momentary (mechanical) switching of DC into inductive loads. The sparks intrigued him. Much later he would refer to radiant energy when he spoke of them.

Whilst opto-coupling will give you far better accuracy, reliabilty, etc, than any other switching method, it may not be the best method for what you are all trying to achieve. Which is O/U.

[casman1969]

You know, its's really tough to just leave things alone and let it run, soooooo..,
I changed up a couple of things.
I now have a two coils (Adams style) in the attract mode. Found that my hollow core only really works in the repel mode or as a pickup so I'm using it as a pickup right now. Still firing seperately but still using my 3A reeds for switching. I do like the arcing within these switches for reasons stated above. This configuration appears to be slightly better in that I can take the center tap of my drive coils and run through a FWB feeding another 9AH battery which charges at the rate of .1V every ten minutes. Loose .01V in that time on the drive battery.
Awaiting the arrival of my new scope to better time and understand the various complex wave forms I'm getting from this arrangement. BTW, to shorten my trigger pulses I've been using some magnetic shielding arround the trigger reeds. Only the scope will confirm that is working.
Also, the two drive coils are wound arround a standard 1/2" bolt with no head. This does aide the attraction mode drive being used.

Will consider the opto answer when the biger unit is complete as photo/opto answer is not really condusive to my bicycle wheel.

Carl