Rectify 3-phase Question

  • Thread starter Watson A.Name - "Watt Sun
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Watson A.Name - "Watt Sun

Guest
I have the spindle drive motor out of a Toshiba CD-ROM drive that has
a rotor that's a steel cup with a magnetized ring inside, I would
guess it has multiple poles. This fits over a laminated stator of 9
arms, each arm having a coil of wire. There are three pads for the
wires from the stator. I'm not sure how the stator is wired, maybe
three sets of three arms in series? There are also three Hall effect
sensors(?) there, too.

I have a red LED soldered across two of the pads, and when I give the
rotor a real good spin, the LED lights up brightly. I can measure the
DC resistance of about 3 ohms between each pad and they're all equal
so I would say that this indicates the windings are equal, i.e. they
are not center tapped. What I'd like to do is rectify the AC output
of the three pads, but how? Should I use 6 diodes like the alternator
in a car has? Or treat it as a center tapped winding?


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
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goes directly to the trash unless you add NOSPAM in the
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Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.19e82d777169a087989752@news.dslextreme.com...
I have the spindle drive motor out of a Toshiba CD-ROM drive that has
a rotor that's a steel cup with a magnetized ring inside, I would
guess it has multiple poles. This fits over a laminated stator of 9
arms, each arm having a coil of wire. There are three pads for the
wires from the stator. I'm not sure how the stator is wired, maybe
three sets of three arms in series?
Click to expand...
Yes indeed.

There are also three Hall effect sensors(?) there, too.
Click to expand...
These alone make disassembly of old floppies worthwhile, too.

I have a red LED soldered across two of the pads, and when I give the
rotor a real good spin, the LED lights up brightly. I can measure the
DC resistance of about 3 ohms between each pad and they're all equal
so I would say that this indicates the windings are equal, i.e. they
are not center tapped. What I'd like to do is rectify the AC output
of the three pads, but how? Should I use 6 diodes like the alternator
in a car has?
Click to expand...
This is a good strategy. Of course, the low output voltage might be
problematic for some, but you have a god deal of experience with electronics so
you can probably visualize at least three ways to do this effectively.
Pick two points and call them minus and plus. Pick a third and call it
common. From each winding, take one wire and run it to the common point. Take
the other and put a pair of diodes on it- cathode from one, anode from the
other. The other ends of the diodes go to the two plus or minus points like
this: flying anodes go to the minus wire, flying cathodes go to the plus wire.
Any capacitor would then go from plus to minus for full voltage, or you have
the option of using half voltages from the coil common to either the plus or the
minus. This gives you bipolar supply capability, or you can just ignore it.
Of course, if you don't mind the excess drop, you can use a bridge rectifier
on each lead and common all the plus outputs and also common all the minus
outputs, but this is really wasteful. And, use some Schottky rectifiers for the
best output overall. They are pretty common on old modem cards and other
computer cards as surface mount devices.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip
 
Hi Watt Sun,

Three phase bridge rectifier.

http://www.ixys.net/l055.pdf

Put a cap on the output and have fun. If you want more voltage use a
‘Voltage Doubler’.

Jay

..
----------------------------------------------------------------------------
"I'm pullin' for you; we're all in this together", Red Green
----------------------------------------------------------------------------
..
..
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.19e82d777169a087989752@news.dslextreme.com...
I have the spindle drive motor out of a Toshiba CD-ROM drive that has
a rotor that's a steel cup with a magnetized ring inside, I would
guess it has multiple poles. This fits over a laminated stator of 9
arms, each arm having a coil of wire. There are three pads for the
wires from the stator. I'm not sure how the stator is wired, maybe
three sets of three arms in series? There are also three Hall effect
sensors(?) there, too.

I have a red LED soldered across two of the pads, and when I give the
rotor a real good spin, the LED lights up brightly. I can measure the
DC resistance of about 3 ohms between each pad and they're all equal
so I would say that this indicates the windings are equal, i.e. they
are not center tapped. What I'd like to do is rectify the AC output
of the three pads, but how? Should I use 6 diodes like the alternator
in a car has? Or treat it as a center tapped winding?


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
Click to expand...
 
In article <_7yfb.53247$Of2.2075854@twister.tampabay.rr.com>,
aichipREM@OVEcfl.THISrr.com mentioned...
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.19e82d777169a087989752@news.dslextreme.com...
I have the spindle drive motor out of a Toshiba CD-ROM drive that has
a rotor that's a steel cup with a magnetized ring inside, I would
guess it has multiple poles. This fits over a laminated stator of 9
arms, each arm having a coil of wire. There are three pads for the
wires from the stator. I'm not sure how the stator is wired, maybe
three sets of three arms in series?

Yes indeed.

There are also three Hall effect sensors(?) there, too.

These alone make disassembly of old floppies worthwhile, too.

I have a red LED soldered across two of the pads, and when I give the
rotor a real good spin, the LED lights up brightly. I can measure the
DC resistance of about 3 ohms between each pad and they're all equal
so I would say that this indicates the windings are equal, i.e. they
are not center tapped. What I'd like to do is rectify the AC output
of the three pads, but how? Should I use 6 diodes like the alternator
in a car has?

This is a good strategy. Of course, the low output voltage might be
problematic for some, but you have a god deal of experience with electronics so
you can probably visualize at least three ways to do this effectively.
Pick two points and call them minus and plus. Pick a third and call it
common. From each winding, take one wire and run it to the common point. Take
the other and put a pair of diodes on it- cathode from one, anode from the
other. The other ends of the diodes go to the two plus or minus points like
this: flying anodes go to the minus wire, flying cathodes go to the plus wire.
Any capacitor would then go from plus to minus for full voltage, or you have
the option of using half voltages from the coil common to either the plus or the
minus. This gives you bipolar supply capability, or you can just ignore it.
Of course, if you don't mind the excess drop, you can use a bridge rectifier
on each lead and common all the plus outputs and also common all the minus
outputs, but this is really wasteful. And, use some Schottky rectifiers for the
best output overall. They are pretty common on old modem cards and other
computer cards as surface mount devices.
Click to expand...
Perhaps I didn't make it clear enough. There are only three pads for
all the windings. I think this means they're connected as a wye or
"Y", not Delta, because I see only three wires coming from the coils
down to the pads. From your description above, it seems that you're
describing how to connect three separate windings, i.e. six leads. If
I connect any winding wire to another, I'd get a short. At the bottom
of this web page there is a schematic of an alternator stator and
rectifier bridge. I believe that's the way the windings are connected
on this spindle motor, and I'm guessing that's the way I should
connect the six diodes, as shown in this schematic.
http://www.mightymo.org/Proj_OneWire.html

I bought a bunch of 1N5818 schottky rectifiers, so no problem there.
I haven't had much success in IDing the surface mount diodes or
transistors from PC boards. Some of the three terminal devices on
PCBs are marked diodes, even tho they're in a transistor package.
That's enough to mess with your mind. I'm still trying to ID some
smt transistors, but the lists I've found don't show them. And this
is even tho the PCBs are from the mid-'90s -- five or ten years old.
Thanks.

Cheers!

Chip Shults
Click to expand...

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
In article <YqadndBStuzq4eKiXTWJjw@wideopenwest.com>,
happyhobit@wideopenwest.com mentioned...
Hi Watt Sun,

Three phase bridge rectifier.

http://www.ixys.net/l055.pdf

Put a cap on the output and have fun. If you want more voltage use a
‘Voltage Doubler’.

Jay
Click to expand...
Yeah, I guess that's the same as the one at the bottom of this URL.
After I looked at it, it looks like they left out a connection dot or
two. http://www.mightymo.org/Proj_OneWire.html

The other way I thought might be okay would be to treat the third leg
as a center tap. Does this make sense? (view with courier font)

+-------------------------->|----+---------o
| D1 |
+--CCCC--+ |
\ winding 3 |
winding 1 \ || + | filter cap
o---CCCC--+---||-----+
Winding 2 / | || |
/ | |
+--CCCC--+ +----------)---------o
| D2 |
+------------------------->|-----+

Thanks.

.
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.19e82d777169a087989752@news.dslextreme.com...
I have the spindle drive motor out of a Toshiba CD-ROM drive that has
a rotor that's a steel cup with a magnetized ring inside, I would
guess it has multiple poles. This fits over a laminated stator of 9
arms, each arm having a coil of wire. There are three pads for the
wires from the stator. I'm not sure how the stator is wired, maybe
three sets of three arms in series? There are also three Hall effect
sensors(?) there, too.

I have a red LED soldered across two of the pads, and when I give the
rotor a real good spin, the LED lights up brightly. I can measure the
DC resistance of about 3 ohms between each pad and they're all equal
so I would say that this indicates the windings are equal, i.e. they
are not center tapped. What I'd like to do is rectify the AC output
of the three pads, but how? Should I use 6 diodes like the alternator
in a car has? Or treat it as a center tapped winding?
--
Click to expand...
--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
Google Groups can't resolve the proper address, so I'll post here in the thread.

Yes, you are correct and that excellent drawing shows it well
(a lot of photos & graphics for a dial-up connection).
The in-phase winding outputs upward thru its diode in the upper group
and the return current from the out-of-phase windings
goes down thru their diodes in the lower group.
 
--
..
----------------------------------------------------------------------------
"I'm pullin' for you; we're all in this together", Red Green
----------------------------------------------------------------------------
..
..
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.19e92eae809f69db989759@news.dslextreme.com...
In article <YqadndBStuzq4eKiXTWJjw@wideopenwest.com>,
happyhobit@wideopenwest.com mentioned...
Hi Watt Sun,

Three phase bridge rectifier.

http://www.ixys.net/l055.pdf

Put a cap on the output and have fun. If you want more voltage use a
‘Voltage Doubler’.

Jay

Yeah, I guess that's the same as the one at the bottom of this URL.
After I looked at it, it looks like they left out a connection dot or
two. http://www.mightymo.org/Proj_OneWire.html

The other way I thought might be okay would be to treat the third leg
as a center tap. Does this make sense? (view with courier font)

+-------------------------->|----+---------o
| D1 |
+--CCCC--+ |
\ winding 3 |
winding 1 \ || + | filter cap
o---CCCC--+---||-----+
Winding 2 / | || |
/ | |
+--CCCC--+ +----------)---------o
| D2 |
+------------------------->|-----+

Thanks.

.
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.19e82d777169a087989752@news.dslextreme.com...
I have the spindle drive motor out of a Toshiba CD-ROM drive that has
a rotor that's a steel cup with a magnetized ring inside, I would
guess it has multiple poles. This fits over a laminated stator of 9
arms, each arm having a coil of wire. There are three pads for the
wires from the stator. I'm not sure how the stator is wired, maybe
three sets of three arms in series? There are also three Hall effect
sensors(?) there, too.

I have a red LED soldered across two of the pads, and when I give the
rotor a real good spin, the LED lights up brightly. I can measure the
DC resistance of about 3 ohms between each pad and they're all equal
so I would say that this indicates the windings are equal, i.e. they
are not center tapped. What I'd like to do is rectify the AC output
of the three pads, but how? Should I use 6 diodes like the alternator
in a car has? Or treat it as a center tapped winding?
--



--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
Click to expand...
 
Hi Watt Sun,

(Fat fingered that one)

Nice text drawing.

The only drawback, I can see, is that it’s half-wave. You lose half the
power, or maybe half of two thirds. Half wave on two phases.

It would be interesting to do it both ways and see how much difference in
power output is.

Jay

--
..
----------------------------------------------------------------------------
"I'm pullin' for you; we're all in this together", Red Green
----------------------------------------------------------------------------
..
..
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.19e92eae809f69db989759@news.dslextreme.com...
In article <YqadndBStuzq4eKiXTWJjw@wideopenwest.com>,
happyhobit@wideopenwest.com mentioned...
Hi Watt Sun,

Three phase bridge rectifier.

http://www.ixys.net/l055.pdf

Put a cap on the output and have fun. If you want more voltage use a
‘Voltage Doubler’.

Jay

Yeah, I guess that's the same as the one at the bottom of this URL.
After I looked at it, it looks like they left out a connection dot or
two. http://www.mightymo.org/Proj_OneWire.html

The other way I thought might be okay would be to treat the third leg
as a center tap. Does this make sense? (view with courier font)

+-------------------------->|----+---------o
| D1 |
+--CCCC--+ |
\ winding 3 |
winding 1 \ || + | filter cap
o---CCCC--+---||-----+
Winding 2 / | || |
/ | |
+--CCCC--+ +----------)---------o
| D2 |
+------------------------->|-----+

Thanks.

.
"Watson A.Name - Watt Sun" <alondra101@hotmail.com> wrote in message
news:MPG.19e82d777169a087989752@news.dslextreme.com...
I have the spindle drive motor out of a Toshiba CD-ROM drive that has
a rotor that's a steel cup with a magnetized ring inside, I would
guess it has multiple poles. This fits over a laminated stator of 9
arms, each arm having a coil of wire. There are three pads for the
wires from the stator. I'm not sure how the stator is wired, maybe
three sets of three arms in series? There are also three Hall effect
sensors(?) there, too.

I have a red LED soldered across two of the pads, and when I give the
rotor a real good spin, the LED lights up brightly. I can measure the
DC resistance of about 3 ohms between each pad and they're all equal
so I would say that this indicates the windings are equal, i.e. they
are not center tapped. What I'd like to do is rectify the AC output
of the three pads, but how? Should I use 6 diodes like the alternator
in a car has? Or treat it as a center tapped winding?
--



--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
Click to expand...
 
I still think the Delco print contains all the ideas you need.
Center-tapped is not necessary,
in fact the voltage in that 3rd winding will buck what you get from the other 2.
You will also lose the 3-phase advantage and get a lumpier DC.
.......
| .
| .
| .
| .
| Va-b = 1.732 * Va <--- Leg #3 will buck this
| .
/ \ .
/ \ .
/ \ .
/ \ .
/ \ .
/ \.
 
In article <f8b945bc.0310052246.272f0f2f@posting.google.com>,
jeffm_@email.com mentioned...
I still think the Delco print contains all the ideas you need.
Center-tapped is not necessary,
in fact the voltage in that 3rd winding will buck what you get from the other 2.
You will also lose the 3-phase advantage and get a lumpier DC.
.......
| .
| .
| .
| .
| Va-b = 1.732 * Va <--- Leg #3 will buck this
| .
/ \ .
/ \ .
/ \ .
/ \ .
/ \ .
/ \.
Click to expand...

Yeah, I would think that the center tapped wouldn't be a good as the
full wave. But the full wave has an additional diode drop per leg.
At these low voltages, that might be more important. Thanks.


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
"Watson A.Name - Watt Sun" wrote:
I have the spindle drive motor out of a Toshiba CD-ROM drive that has
a rotor that's a steel cup with a magnetized ring inside, I would
guess it has multiple poles. This fits over a laminated stator of 9
arms, each arm having a coil of wire. There are three pads for the
wires from the stator. I'm not sure how the stator is wired, maybe
three sets of three arms in series? There are also three Hall effect
sensors(?) there, too.

I have a red LED soldered across two of the pads, and when I give the
rotor a real good spin, the LED lights up brightly. I can measure the
DC resistance of about 3 ohms between each pad and they're all equal
so I would say that this indicates the windings are equal, i.e. they
are not center tapped. What I'd like to do is rectify the AC output
of the three pads, but how? Should I use 6 diodes like the alternator
in a car has? Or treat it as a center tapped winding?

--
Click to expand...
Have you considered making the bridge out of six LEDs, and putting a
resistor between the + and _ outputs to set the current? You should get
more light, and waste less cranking energy getting light.


--


Michael A. Terrell
Central Florida
 
In article <3F9DDDFC.9745328@earthlink.net>,
mike.terrell@earthlink.net mentioned...
"Watson A.Name - Watt Sun" wrote:

I have the spindle drive motor out of a Toshiba CD-ROM drive that has
a rotor that's a steel cup with a magnetized ring inside, I would
guess it has multiple poles. This fits over a laminated stator of 9
arms, each arm having a coil of wire. There are three pads for the
wires from the stator. I'm not sure how the stator is wired, maybe
three sets of three arms in series? There are also three Hall effect
sensors(?) there, too.

I have a red LED soldered across two of the pads, and when I give the
rotor a real good spin, the LED lights up brightly. I can measure the
DC resistance of about 3 ohms between each pad and they're all equal
so I would say that this indicates the windings are equal, i.e. they
are not center tapped. What I'd like to do is rectify the AC output
of the three pads, but how? Should I use 6 diodes like the alternator
in a car has? Or treat it as a center tapped winding?

--

Have you considered making the bridge out of six LEDs, and putting a
resistor between the + and _ outputs to set the current? You should get
more light, and waste less cranking energy getting light.
Click to expand...
Well, right now I'm still using just a single LED, no resistor,
nothing else. Can't get much more efficient than that. But I thought
that it might be a good idea to use the rectifiers if I put a big cap
on the output to store up a bit of muscle power. I was thinking maybe
a couple 1F caps might help... ;-)


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@
 
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