B
bakalorz
Guest
Well, I guess I should start a new thread for this rather than hijacking
the other thread.
As mentioned in my post there, I agreed with the person who said he was
disappointed cberkeley is charging for his design.
I didn't plan to start posting about this regulator till it was further
along, but given cberkeley's has apparently gone on hold, I figure I will put some preliminary info out.
When I first started to read that thread I had hoped that cberkeley was
going to put the design out as public domain, and that several people
would end up experimenting with it to refine and adapt the design.
Since that apparently won't happen, I am hoping that people will end up
doing so with this one.
I will put mine out as freeware and am hoping for suggestions and
feedback, to refine the design if required
Plus, when the design is coming together, I would like some help with the documentation ...
My goal is a bit different than the other regulator.
Cberkeley's design philosophy seems to be to build the best regulator he
can build, without much regard to cost.
My goal is to build the most economical regulator that is still
completely functionally adequate for all the GS series bikes.
The first thing I tried was googling to see if there are any other
designs out there that I could use.
I only found one complete design, which is at
www.takisnet.org/~abayko/vreg.pdf
Amusingly enough, it was for a Suzuki GS400E (What an unexpected
co-incidence that another Suzuki needed a regulator)
--- btw, in case anyone decides to build it, the schematic for this
one has the bottom 3 bridge diodes (D5, D6, and D7) upside-down.
Googling was kind of frustrating, because the term shunt regulator
(which is what these are) is also commonly used in other contexts in
electronics, to say nothing of all the regulators for sale in the
windpower generation market. So there may be other designs out there,
but I got tired of sorting through all the extraneous links to try to
find them.
If there is anyone out there with better googling skills than I, that can
find some more freebie regulators out there for comparison and to see
alternate ways of doing things, I would appreciate it.
keywords would include Permanent magnet alternator and shunt regulator.
You do not want any regulators that modulate current through a field
coil, they are for a different kind of alternator.
In any case, what I found was that the designs are usually a three-
phase rectifier bridge, one for each lead of the stator. Each stator
connection can also be shorted to ground via an SCR, which is how the
regulation is accomplished.
The only real variations in the designs seem to be the control circuit
that is used to tell the SCRs when to fire.
The simplest designs just have 3 zener diodes, one connected to the gate
of each SCR.
According to my Clymer manual, Suzuki's design seems to have one zener
feeding a 2 transistor amplifier which then feeds all the SCRs.
The web design mentioned above has a differential pair of transistors
which drive all the SCRs.
I have no idea of what cberkeley's control circuit is.
By the way ... throughout the course of this post I will compare my
design to the web design and what I know of cberkeley's design, this is
primarily to help any readers see both the differences and commonalities
in the designs and the reasons for the designs being the way they are.
Also, it will hopefully help readers to understand the reasons behind
the design differences and to make an informed choice for what will fit
their needs the best, or to make suggestions for changes to try.
It should not be taken to imply that any of the designs are "better" than
any of the others.
Anyway ...
At least some of the stock Suzuki regulators are somewhat different than
described above. I don't know how all are set up, but what I found for
mine is that one of the stator phases is switched through the "lights on"
switch. When the lights are off, this phase is not used at all.
When the lights are on, this phase is in the circuit.
Additionally, the switched phase is unregulated (i.e. it has no SCR)
There is conflicting info about the other 2 phases out there.
The Clymer manual says they are both regulated, but I remember seeing
somewhere that only one of them is.
Having given the background, here is where I am with my design.
My design will have all three phases regulated. Even if I leave the
"switched phase" idea in, regulating it is OK, that SCR will just be
firing with nothing to do ...
Control Circuitry:
I am dithering on the control circuitry.
The differential pair promises easy adjustability, but it has a high
quiescent current. To avoid draining the battery when the bike is off,
the voltage sense lead must be a switched lead, which I would strongly
like to avoid.
A design like Suzuki's seems good, but may be difficult to get to have
as much adjustability as I want. (yes, my regulator will be adjustable
too) However; done right, Suzuki's design should allow me not to have
to run the sense lead from a switched lead.
Since the parts for the control circuits are all dirt cheap, I will
probably build one of each just to see what I like better.
Power Circuits:
Most of the expense comes in the power circuitry.
This is where over specifying the parts costs money, and under specifying them lets the smoke out.
These are also the physically "big" parts that will determine the
enclosure size required.
The Bridge Rectifier Section:
The "right" way to build the bridge is to use a 3 phase rectifier.
These are expensive, but will allow a physically very small unit.
cberkeley uses one and a half normal (4 terminal) 40 amp bridge rectifiers.
This is an OK way to do this, but bugs me (irrationally ???) because it
does not maintain symmetry. Also, one of the rectifiers will run hotter
than the other ... probably no big deal, but it could change the timing
of when the SCRs fire, leading to unbalanced load on the stator coils
(probably wouldn't matter in actuality ... but I like Symmetry)
If space will allow, I think I will use 3 normal bridge rectifiers, and
parallel the diodes in each one. This would effectively double the
current rating, allowing the individual parts to be specified as more
available, less expensive 25 amp units. Physical size will of course
increase by one square inch ... but trilateral symmetry will be
conserved.
FWIW the author of the other regulator on the web said he used 12 amp
rectifiers successfully ... I'm not sure if he used 2 or 3 ...
... or even a single 3 phase
SCRs
I plan to use 25 amp SCRs. (at $4.47 for 3 of them)
cberkeley uses 35 amp SCRs. (at apparently $39 for all three)
The web design used 8 amp SCRs successfully.
Sizing the SCRs is perhaps the most controversial part of the design.
The rectifier bridge will see pretty much the full output current all
the time.
But the SCRs will only see the "excess" current which the alternator
makes but is not needed by the loads on the bike.
Given that the battery is always charging and the ignition circuit is
always igniting, there is at least a minimal load that will always
be there when the bike is running.
In most cases in the US, the lights will always be on as well.
(and if not, Suzuki's OEM wiring will thoughtfully disconnect one of the
phases from the alternator for you when the lights are off ...)
Further, even if there were no loads at all on the bike, each SCR will
only see a 33% duty cycle.
In one of the posts in the other thread, Nerobro said that the biggest
alternator on the GSes was a 28 amp on the GS1100s
Assuming 3-5 amps for charging and running the ignition, the 25 amp SCRs
would be (just barely) enough. All in all, given the duty cycle and the
fact that other loads will likely be on too, I am pretty confident that
it should be MORE than enough.
Of course you could also find some bigger SCRs and use them instead.
If any readers find a source of bigger SCRs for cheap, let me know and I
will uprate the design.
(note: if you wish to substitute SCRs, the ones I am using have an
insulated tab, if the ones you wish to use do not, make sure that
they can be connected to ground (assuming the heat sink is grounded))
Filter capacitor.
cberkeley is apparently providing a BEEG @SS filter capacitor in his
design to allow running the bike without a battery.
I am not. I think it's money (and a lot of space) for something that is not
needed.
Plus, I don't really trust it to filter adequately.
If you want it, you will have to add it on your own, or build the other
design
Status of the project
I have pretty much figured out all the components I need, and am
compiling a list for mail ordering them.
(complicated by the fact that I want to order the parts for 5 projects
at once:
1) the regulator
2) an LM3914 based voltage monitor for the bike
3) a Headlight Modulator for the bike
4) a brake light flasher for the bike
5) a motor controller for a radio controlled model airplane.
That's where I am with the project right now.
I'll be posting more as the project goes along.
the other thread.
As mentioned in my post there, I agreed with the person who said he was
disappointed cberkeley is charging for his design.
I didn't plan to start posting about this regulator till it was further
along, but given cberkeley's has apparently gone on hold, I figure I will put some preliminary info out.
When I first started to read that thread I had hoped that cberkeley was
going to put the design out as public domain, and that several people
would end up experimenting with it to refine and adapt the design.
Since that apparently won't happen, I am hoping that people will end up
doing so with this one.
I will put mine out as freeware and am hoping for suggestions and
feedback, to refine the design if required
Plus, when the design is coming together, I would like some help with the documentation ...
My goal is a bit different than the other regulator.
Cberkeley's design philosophy seems to be to build the best regulator he
can build, without much regard to cost.
My goal is to build the most economical regulator that is still
completely functionally adequate for all the GS series bikes.
The first thing I tried was googling to see if there are any other
designs out there that I could use.
I only found one complete design, which is at
www.takisnet.org/~abayko/vreg.pdf
Amusingly enough, it was for a Suzuki GS400E (What an unexpected
co-incidence that another Suzuki needed a regulator)
--- btw, in case anyone decides to build it, the schematic for this
one has the bottom 3 bridge diodes (D5, D6, and D7) upside-down.
Googling was kind of frustrating, because the term shunt regulator
(which is what these are) is also commonly used in other contexts in
electronics, to say nothing of all the regulators for sale in the
windpower generation market. So there may be other designs out there,
but I got tired of sorting through all the extraneous links to try to
find them.
If there is anyone out there with better googling skills than I, that can
find some more freebie regulators out there for comparison and to see
alternate ways of doing things, I would appreciate it.
keywords would include Permanent magnet alternator and shunt regulator.
You do not want any regulators that modulate current through a field
coil, they are for a different kind of alternator.
In any case, what I found was that the designs are usually a three-
phase rectifier bridge, one for each lead of the stator. Each stator
connection can also be shorted to ground via an SCR, which is how the
regulation is accomplished.
The only real variations in the designs seem to be the control circuit
that is used to tell the SCRs when to fire.
The simplest designs just have 3 zener diodes, one connected to the gate
of each SCR.
According to my Clymer manual, Suzuki's design seems to have one zener
feeding a 2 transistor amplifier which then feeds all the SCRs.
The web design mentioned above has a differential pair of transistors
which drive all the SCRs.
I have no idea of what cberkeley's control circuit is.
By the way ... throughout the course of this post I will compare my
design to the web design and what I know of cberkeley's design, this is
primarily to help any readers see both the differences and commonalities
in the designs and the reasons for the designs being the way they are.
Also, it will hopefully help readers to understand the reasons behind
the design differences and to make an informed choice for what will fit
their needs the best, or to make suggestions for changes to try.
It should not be taken to imply that any of the designs are "better" than
any of the others.
Anyway ...
At least some of the stock Suzuki regulators are somewhat different than
described above. I don't know how all are set up, but what I found for
mine is that one of the stator phases is switched through the "lights on"
switch. When the lights are off, this phase is not used at all.
When the lights are on, this phase is in the circuit.
Additionally, the switched phase is unregulated (i.e. it has no SCR)
There is conflicting info about the other 2 phases out there.
The Clymer manual says they are both regulated, but I remember seeing
somewhere that only one of them is.
Having given the background, here is where I am with my design.
My design will have all three phases regulated. Even if I leave the
"switched phase" idea in, regulating it is OK, that SCR will just be
firing with nothing to do ...
Control Circuitry:
I am dithering on the control circuitry.
The differential pair promises easy adjustability, but it has a high
quiescent current. To avoid draining the battery when the bike is off,
the voltage sense lead must be a switched lead, which I would strongly
like to avoid.
A design like Suzuki's seems good, but may be difficult to get to have
as much adjustability as I want. (yes, my regulator will be adjustable
too) However; done right, Suzuki's design should allow me not to have
to run the sense lead from a switched lead.
Since the parts for the control circuits are all dirt cheap, I will
probably build one of each just to see what I like better.
Power Circuits:
Most of the expense comes in the power circuitry.
This is where over specifying the parts costs money, and under specifying them lets the smoke out.
These are also the physically "big" parts that will determine the
enclosure size required.
The Bridge Rectifier Section:
The "right" way to build the bridge is to use a 3 phase rectifier.
These are expensive, but will allow a physically very small unit.
cberkeley uses one and a half normal (4 terminal) 40 amp bridge rectifiers.
This is an OK way to do this, but bugs me (irrationally ???) because it
does not maintain symmetry. Also, one of the rectifiers will run hotter
than the other ... probably no big deal, but it could change the timing
of when the SCRs fire, leading to unbalanced load on the stator coils
(probably wouldn't matter in actuality ... but I like Symmetry)
If space will allow, I think I will use 3 normal bridge rectifiers, and
parallel the diodes in each one. This would effectively double the
current rating, allowing the individual parts to be specified as more
available, less expensive 25 amp units. Physical size will of course
increase by one square inch ... but trilateral symmetry will be
conserved.
FWIW the author of the other regulator on the web said he used 12 amp
rectifiers successfully ... I'm not sure if he used 2 or 3 ...
... or even a single 3 phase
SCRs
I plan to use 25 amp SCRs. (at $4.47 for 3 of them)
cberkeley uses 35 amp SCRs. (at apparently $39 for all three)
The web design used 8 amp SCRs successfully.
Sizing the SCRs is perhaps the most controversial part of the design.
The rectifier bridge will see pretty much the full output current all
the time.
But the SCRs will only see the "excess" current which the alternator
makes but is not needed by the loads on the bike.
Given that the battery is always charging and the ignition circuit is
always igniting, there is at least a minimal load that will always
be there when the bike is running.
In most cases in the US, the lights will always be on as well.
(and if not, Suzuki's OEM wiring will thoughtfully disconnect one of the
phases from the alternator for you when the lights are off ...)
Further, even if there were no loads at all on the bike, each SCR will
only see a 33% duty cycle.
In one of the posts in the other thread, Nerobro said that the biggest
alternator on the GSes was a 28 amp on the GS1100s
Assuming 3-5 amps for charging and running the ignition, the 25 amp SCRs
would be (just barely) enough. All in all, given the duty cycle and the
fact that other loads will likely be on too, I am pretty confident that
it should be MORE than enough.
Of course you could also find some bigger SCRs and use them instead.
If any readers find a source of bigger SCRs for cheap, let me know and I
will uprate the design.
(note: if you wish to substitute SCRs, the ones I am using have an
insulated tab, if the ones you wish to use do not, make sure that
they can be connected to ground (assuming the heat sink is grounded))
Filter capacitor.
cberkeley is apparently providing a BEEG @SS filter capacitor in his
design to allow running the bike without a battery.
I am not. I think it's money (and a lot of space) for something that is not
needed.
Plus, I don't really trust it to filter adequately.
If you want it, you will have to add it on your own, or build the other
design
Status of the project
I have pretty much figured out all the components I need, and am
compiling a list for mail ordering them.
(complicated by the fact that I want to order the parts for 5 projects
at once:
1) the regulator
2) an LM3914 based voltage monitor for the bike
3) a Headlight Modulator for the bike
4) a brake light flasher for the bike
5) a motor controller for a radio controlled model airplane.
That's where I am with the project right now.
I'll be posting more as the project goes along.
