Rectifier/Regulator circuit for an outboard motor?

[Sunny]

Both of your points are good, and I don't have answers. I wouldn't
expect the two coils to be interchangable.

A PM-based alternator would certainly work in the sense of producing
power. I just don't know how a regulator would work. If there is 170
volts at full throttle, and the alternator can produce, say, 20 amps,
then a linear regulator that regulates 170 volts down to 14 volts would
dissipate 156V x 20 amps = 3120 watts! That is clearly ludicrous - but
I don't know how else it would regulate if you can't reduce the voltage
via a field coil. Maybe it's like a cycle-counting light dimmer? I'm
not convinced that would work, either.

I guess I'm out of my area of expertise, so I will wish you luck and
fade back into lurking mode.

Once again, Bill makes good sense even when out of his depth

You've confirmed my thoughts - there's no reasonable way to regulate an
AC input which varies from 15-170v to a constant 12-14v DC, therefore
the input must be controlled, presumably via a field coil.

We know that a permanent magnet alternator *can* be designed with a
field coil, since that's the scheme described in the service manual I
was reading on the weekend - but unfortunately this particular manual is
third party, and written in colloquial language by an author clearly
more comfortable with mechanical things - his description of the
alternator theory of operation was amusing but not particularly
illuminating I'll read it again this weekend and see if I can't
glean a better understanding.

The alternator output current probably falls somewhere between your
estimate and Ken's, given my old manual contains a paragraph detailing
how to determine whether you are dealing with a 9 amp or 15 amp
alternator - apparently a given motor might been fitted with either.

Thanks again, and I'll post updates as appropriate.

Sunny

 

[Asimov]

"Sunny" bravely wrote to "All" (09 Jun 04 20:24:38)
--- on the heady topic of "Re: Rectifier/Regulator circuit for an outboard motor?"

Su> From: Sunny <[email protected]>
Su> You've confirmed my thoughts - there's no reasonable way to regulate
Su> an AC input which varies from 15-170v to a constant 12-14v DC,
Su> therefore the input must be controlled, presumably via a field coil.

If it is pulsating then I think it can be controlled with techniques
like using for example a zener reference tied to the base of a pass
power transistor. This means charging a tank capacitor with current
rather than voltage thus making the required power transformation.
The pass transistor would only allow current to flow when the emitter
voltage was lower than the zener reference. It would need to be a
higher voltage of at least 200 to 300 volts type at a few 10's of
amperes.

Another way would be to simply rectify the magneto output and use a
pwm switching regulator to derive the required 12 volts. Thus the
input voltage could vary from 15 to 170 v and still recover the 12
volts efficiently enough.

A*s*i*m*o*v

.... Digital circuits are made from analog parts.

 

[t.hoehler]

Another way would be to simply rectify the magneto output and use a
pwm switching regulator to derive the required 12 volts. Thus the
input voltage could vary from 15 to 170 v and still recover the 12
volts efficiently enough.

If this is just a flywheel magnet generator, then it might be similar to
what the motorcycle engines use. They have a similar set up, they call it a
lighting coil, and it works fine as long as you have a substantial 12 load
on it, ie the headlight and the taillight. Maybe if you load this coil with
a suitable resistor, you can see less of a swing in output voltage. I
remember on my 185 Suzuki the headlight would get somewhat dim at idle, but
perk right up to full brightness when you revved the engine anywhere above
1000 rpm. It was a cheap and dirty generating system, but not sure it is the
same as what you have there.

Regards,
Tom

 

[Bill Jeffrey]

Another way would be to simply rectify the magneto output and use a
pwm switching regulator to derive the required 12 volts. Thus the
input voltage could vary from 15 to 170 v and still recover the 12
volts efficiently enough.

Emerging from lurk mode for a bit, Bill writes:
This would be similar to the MPPT (Maximmum Power Point Tracker)
battery-charge controllers that photovoltaic solar-panel owners
sometimes use. They are fairly elaborate and fairly expesnive (and
relatively new), but are designed to wring every last watt-hour out of
the expensive solar panels. One wold probably be overkill here.

If this is just a flywheel magnet generator, then it might be similar to
what the motorcycle engines use. They have a similar set up, they call it a
lighting coil, and it works fine as long as you have a substantial 12 load
on it, ie the headlight and the taillight. Maybe if you load this coil with
a suitable resistor, you can see less of a swing in output voltage. I
remember on my 185 Suzuki the headlight would get somewhat dim at idle, but
perk right up to full brightness when you revved the engine anywhere above
1000 rpm. It was a cheap and dirty generating system, but not sure it is the
same as what you have there.

Actually, Tom, I think you have hit it right on the head. I've been
thinking about this, and finally figured out that a load would pull the
voltage down quite a bit. It would have to be quite a load, considering
what happened to Sunnyboy's electrolytic capacitor (50 volt rated,
IIRC), but the intended load was undoubtedly a 12-volt battery for
electric starting.

According to what I have found on the web, there is indeed a regulator
intended to go with the battery (unlike the situation with your
motorcycle) to prevent overcharging the battery. There are two kinds of
simple regulators for this situation. One is a shunt regulator, which
is essentially a big honkin' zener diode clamped right across the stator
winding. Anytime the voltage tries to rise above 14 volts, the zener
begins to conduct, shorting the excess current to ground. This
increased current provides, in essense, a variable load, and as you
describe, clamps the voltage to 14 volts. The advantage of a shunt
regulator is simplicity. The disadvantage is that it dissipates A LOT
of power as heat at high engine speeds, and has to be heat-sunk
extremely well.

The other type is a series regulator. It is essentially a switch in
series with the stator winding. When the voltage gets too high, the
switch opens, preventing excess voltage or current from passing. Since
the alternator produces AC, the output voltage goes low again in a few
milliseconds, the switch recloses, and the process repeats on the next
AC cycle. The adsvantage is that very little power is dissipated. The
disadvantge (until recently) is that high-voltage switching transistors
are needed.

My guess is that the proper regulator for this thing is a series
switching regulator. The pictures of them show a relatively small
physical package, which I think would be too small for the heat
generated by a shunt regulator.

Bill - returning to lurk mode.

 

[Asimov]

"t.hoehler" bravely wrote to "All" (14 Jun 04 02:20:15)
--- on the heady topic of "Re: Rectifier/Regulator circuit for an outboard motor?"

t.> If this is just a flywheel magnet generator, then it might be similar
t.> to what the motorcycle engines use. They have a similar set up, they
t.> call it a lighting coil, and it works fine as long as you have a
t.> substantial 12 load on it, ie the headlight and the taillight. Maybe if
t.> you load this coil with a suitable resistor, you can see less of a
t.> swing in output voltage. I remember on my 185 Suzuki the headlight
t.> would get somewhat dim at idle, but perk right up to full brightness
t.> when you revved the engine anywhere above 1000 rpm. It was a cheap and
t.> dirty generating system, but not sure it is the same as what you have
t.> there.

In theory however, the voltage should level off to match the flux
level of the magnets. IOW it would not generate infinite voltage at
infinite speed.

However, one thing comes to mind in that such a simple magneto may
have a resonnance effect between its winding inductance and stray
capacitance at higher rpm and we observe a substantial voltage rise
when lightly loaded as by the dmm.

Perhaps this resonnant voltage rise is designed into such generators
on purpose to reduce the effect of the increasing inductive reactance.
I agree, as with your motorcycle experience, a sufficient lamp load
will probably dampen the voltage rise at a higher rpm.

A*s*i*m*o*v

.... Inductor designers do it in the gap.

 

[Sunny]

Emerging from lurk mode for a bit, Bill writes:
This would be similar to the MPPT (Maximmum Power Point Tracker)
battery-charge controllers that photovoltaic solar-panel owners
sometimes use. They are fairly elaborate and fairly expesnive (and
relatively new), but are designed to wring every last watt-hour out of
the expensive solar panels. One wold probably be overkill here.



Actually, Tom, I think you have hit it right on the head. I've been
thinking about this, and finally figured out that a load would pull the
voltage down quite a bit. It would have to be quite a load, considering
what happened to Sunnyboy's electrolytic capacitor (50 volt rated,
IIRC), but the intended load was undoubtedly a 12-volt battery for
electric starting.

Yep, it was a 50v capacitor and the only load at time of explosion was
an analog voltmeter.

According to what I have found on the web, there is indeed a regulator
intended to go with the battery (unlike the situation with your
motorcycle) to prevent overcharging the battery. There are two kinds of
simple regulators for this situation. One is a shunt regulator, which
is essentially a big honkin' zener diode clamped right across the stator
winding. Anytime the voltage tries to rise above 14 volts, the zener
begins to conduct, shorting the excess current to ground. This
increased current provides, in essense, a variable load, and as you
describe, clamps the voltage to 14 volts. The advantage of a shunt
regulator is simplicity. The disadvantage is that it dissipates A LOT
of power as heat at high engine speeds, and has to be heat-sunk
extremely well.

I finally got a chance to bend a knowledgeable ear at the marina last
weekend, and he says the 'lighting coils' available as accessories for
manual-start only outboards are exactly that - a coil and zener diode
potted together and designed to be mounted under the flywheel to power
12v running lights - no battery required, but the lights don't work
below 1/3 throttle and the assembly tends to fail frequently. That
sounds like the motorcycle solution to me, but is not what I have under
my outboard flywheel according to the guy at the marina.

The other type is a series regulator. It is essentially a switch in
series with the stator winding. When the voltage gets too high, the
switch opens, preventing excess voltage or current from passing. Since
the alternator produces AC, the output voltage goes low again in a few
milliseconds, the switch recloses, and the process repeats on the next
AC cycle. The adsvantage is that very little power is dissipated. The
disadvantge (until recently) is that high-voltage switching transistors
are needed.

My guess is that the proper regulator for this thing is a series
switching regulator. The pictures of them show a relatively small
physical package, which I think would be too small for the heat
generated by a shunt regulator.

Your guess agrees with the marina guy's explanation - he says it's a
2-phase alternator (the two yellow wires plus ground) feeding a potted
regulator which is more durable than a lighting coil but still tends to
fail if you don't keep the battery connections clean. He says the older
designs which used a field coil and single-phase alternator were more
tolerant of poor connections but also more expensive to repair.

I bought an 8 amp-hour motorcycle battery which fits in the only
available protected space, so my lights now work. The regulator designed
for my motor is on order and should arrive before I have to recharge the
battery I'm assured this setup will work, but durability may be an
issue.

I'm a little disappointed not to have come up with a cheap homebrew
solution, but many thanks to Bill and all others who provided input.

Sunny

 

[rayjking]

Yep, it was a 50v capacitor and the only load at time of explosion was
an analog voltmeter.


I finally got a chance to bend a knowledgeable ear at the marina last
weekend, and he says the 'lighting coils' available as accessories for
manual-start only outboards are exactly that - a coil and zener diode
potted together and designed to be mounted under the flywheel to power
12v running lights - no battery required, but the lights don't work
below 1/3 throttle and the assembly tends to fail frequently. That
sounds like the motorcycle solution to me, but is not what I have under
my outboard flywheel according to the guy at the marina.


Your guess agrees with the marina guy's explanation - he says it's a
2-phase alternator (the two yellow wires plus ground) feeding a potted
regulator which is more durable than a lighting coil but still tends to
fail if you don't keep the battery connections clean. He says the older
designs which used a field coil and single-phase alternator were more
tolerant of poor connections but also more expensive to repair.

I bought an 8 amp-hour motorcycle battery which fits in the only
available protected space, so my lights now work. The regulator designed
for my motor is on order and should arrive before I have to recharge the
battery I'm assured this setup will work, but durability may be an
issue.

I'm a little disappointed not to have come up with a cheap homebrew
solution, but many thanks to Bill and all others who provided input.

Sunny
I have the drawings for a single/two phase or three phase regulator if you

like I can mail it to you.

Ray

 

[Sunny]

like I can mail it to you.

Ray

Yes, I would be very interested in having a copy of those drawings.

Could you send them to scsi at sympatico dot ca ?

Thanks!

Sunny

 

[[email protected]]

I finally got a chance to bend a knowledgeable ear at the marina last
weekend, and he says the 'lighting coils' available as accessories for
manual-start only outboards are exactly that - a coil and zener diode
potted together and designed to be mounted under the flywheel to power
12v running lights - no battery required, but the lights don't work
below 1/3 throttle and the assembly tends to fail frequently. That
sounds like the motorcycle solution to me, but is not what I have under
my outboard flywheel according to the guy at the marina.

Actually, it could be a series switch, or a switch that shorts the
coil so it doesn't produce power. Disconnecting the coil wires (or
not loading them sufficiently) will produce high voltages that can
cause problems. Obviously if you're shorting the leads, that requires
diodes after the switch.

I bought an 8 amp-hour motorcycle battery which fits in the only
available protected space, so my lights now work. The regulator designed
for my motor is on order and should arrive before I have to recharge the
battery I'm assured this setup will work, but durability may be an
issue.

If you can't find the reg designed for you motor, find a motorcycle
voltage regulator. Motorcycle typically have a 2-phase or 3-phase
generator (you have a 1-phase). The regulator/rectifier simple shorts
the coil windings when the battery voltage is high enough to
effectively stop the charging process. The short is before the
rectifier diodes, so the battery doesn't get shorted. The electronic
regulators are roughly the size of a cigarrete pack and usually very
reliable. Avoid mechanical type regulators if at all possible.


-Chris

 

[Sunny]

Yes, I would be very interested in having a copy of those drawings.

Could you send them to scsi at sympatico dot ca ?

Thanks!

Sunny

 

[Sunny]

I recently purchased a new work boat with a manual start 30hp 4-stroke
outboard motor. I need to install running lights, and would like to
avoid using a battery.

The outboard has two unused wires leading from a stator coil under the
flywheel which I'm pretty sure would be used for the battery charging
circuit on the electric start model. The owner's manual does not include
a wiring diagram, or other relevant information, but I expect I would
find crude AC - varying in voltage with engine RPM? - on these two
wires. I'm hoping I can rectify and regulate the stator output to 12v DC
to power the running lights.

My initial idea was to use a bridge rectifier and filter capacitor,
followed by a fixed voltage regulator. I salvaged an 8A 50V bridge
rectifier and 10,000uF 50V electrolytic from a dead PC monitor which
should handle the DC conversion, but the only 12v linear regulators
available locally are 7812s which are limited to 1.5A - not quite
enough. An LT1084-12 (5A) would probably be ideal, but is not easily
available to me.

I could possibly use a 7812 with a power transistor bypass to increase
ampacity, but I'm not confident when it comes to selecting a suitable
transistor and associated resistors given the variable (and unknown)
input voltage.

Given the application I would like to keep it minimal and robust.
Perhaps someone has already encountered this problem and designed a
simple solution using commonly available parts?

TIA

Sunny

Off topic, but possibly of interest to participants in this thread,
especially those in Canada.

My new boat was delivered unregistered, and without a capacity plate. On
researching boat licensing requirements at Canadian Government web
sites, I learned that I would first need to send in photographs and
measurements, along with my payment of $5, in order to receive a
capacity plate. The capacity plate will rate the boat's load carrying
capacity, and provide a Hull Identification Number (HIN). Once I have
the HIN, I can apply for registration numbers and paint them on the bow
so the Police will stop pulling me over for driving an unregistered boat.

I sent the in the required information, pictures, and payment, and after
a month received a reply stating that it would take a minimum of 8
months for my application to be processed! The letter authorised me to
operate an unregistered boat until July, 2005 - and said I should carry
the letter in the boat at all times. I have no idea how long the
Government will take to issue registration numbers once I have a HIN -
probably another 8 months!

This is a wonderful example of my tax dollars at work - it appears I
will be operating an unregistered boat for at least another 8 months,
likely considerably longer, and will be pulled over by the Police at
least once a week because I have no registration numbers. My insurance
broker says I *should* be covered by the letter, but heaven forbid I
need to make a claim.

Now I know why many of my fellow cottagers have several boats with the
same registration numbers on them - the Police don't care about validity
of the numbers, they just have to be in the designated location, and of
the right size and contrast.

Sunny

 

[Ken Weitzel]

Off topic, but possibly of interest to participants in this thread,
especially those in Canada.

My new boat was delivered unregistered, and without a capacity plate. On
researching boat licensing requirements at Canadian Government web
sites, I learned that I would first need to send in photographs and
measurements, along with my payment of $5, in order to receive a
capacity plate. The capacity plate will rate the boat's load carrying
capacity, and provide a Hull Identification Number (HIN). Once I have
the HIN, I can apply for registration numbers and paint them on the bow
so the Police will stop pulling me over for driving an unregistered boat.

I sent the in the required information, pictures, and payment, and after
a month received a reply stating that it would take a minimum of 8
months for my application to be processed! The letter authorised me to
operate an unregistered boat until July, 2005 - and said I should carry
the letter in the boat at all times. I have no idea how long the
Government will take to issue registration numbers once I have a HIN -
probably another 8 months!

This is a wonderful example of my tax dollars at work - it appears I
will be operating an unregistered boat for at least another 8 months,
likely considerably longer, and will be pulled over by the Police at
least once a week because I have no registration numbers. My insurance
broker says I *should* be covered by the letter, but heaven forbid I
need to make a claim.

Now I know why many of my fellow cottagers have several boats with the
same registration numbers on them - the Police don't care about validity
of the numbers, they just have to be in the designated location, and of
the right size and contrast.

Hi Sunny...

If it works kinda the same as it does around here,
what should happen is the first cop that sees you and
checks you out will pass it on to the rest, and they'll
ignore you from then on...

At least here they use a lot of discretion, too. I have a
teen grand daughter who has her certificate. They checked
her only once, haven't disturbed her since. And they
did give her discretion, they failed to notice that
she was operating 140 hp - perhaps because she was
"using" only a tiny tiny bit of power.

Ken

 

[Sunny]

An update...

The Marina called me this weekend and said my rectifier/regulator had
finally arrived.

It's the correct part for my motor according to the microfiche, but the
mounting hole spacing doesn't match any of the unused threaded holes on
the engine block, nor do the connectors fit my wiring harness. Not only
does it not fit, the bill was over $200 with taxes! For no more than $20
worth of electronics!

They were most apologetic and offered to try and find the correct part,
but I said I wasn't willing to pay more than $60 in any event.

So I'm back to square one, and would *really* appreciate a circuit
diagram for a rectifier/regulator for a 2-phase alternator suitable for
this application if anyone has one.

TIA

Sunny

 

[Ken Weitzel]

An update...

The Marina called me this weekend and said my rectifier/regulator had
finally arrived.

It's the correct part for my motor according to the microfiche, but the
mounting hole spacing doesn't match any of the unused threaded holes on
the engine block, nor do the connectors fit my wiring harness. Not only
does it not fit, the bill was over $200 with taxes! For no more than $20
worth of electronics!

They were most apologetic and offered to try and find the correct part,
but I said I wasn't willing to pay more than $60 in any event.

So I'm back to square one, and would *really* appreciate a circuit
diagram for a rectifier/regulator for a 2-phase alternator suitable for
this application if anyone has one.

Hi Sunny...

By the strangest of coincidences I fished awhile
with my dealer friend today... (bought a new boat
and motor from him, he and his family delivered it to
the cottage 'cause it's a bit too heavy for my car
to pull)

We discussed your situation... he said though he's
not a Merc dealer, they do service them and do have
manuals. And even if not they can get copies by
contra with one of the merc dealers....

He said you'd need something that sounded like
a rotor/stator plate (expensive) that would
generate the rough too high 12 volts. Then you
need to buy a rectifier/regulator device (expensive
and not long lasting).

I told him you already had two wires coming out,
that they produced up to 160 volts at high rev's.
He looked concerned and confused, asked if they
were yellow? Concluded by saying leave them alone,
they are ignition only, and only brought out for test
purposes.

He too suggested that you'd be best advised to
just use a battery and charge it once or twice a
season.

Though he (Larry Wadge - owner of AVO marine) is
busy this time of year, if you like I'll ask him
when next we meet if he'd mine photocopying the
relevant page(s) for you. It might take time,
though.

Take care.

Ken

 

[[email protected]]

An update...

The Marina called me this weekend and said my rectifier/regulator had
finally arrived.

It's the correct part for my motor according to the microfiche, but the
mounting hole spacing doesn't match any of the unused threaded holes on
the engine block, nor do the connectors fit my wiring harness. Not only
does it not fit, the bill was over $200 with taxes! For no more than $20
worth of electronics!

They were most apologetic and offered to try and find the correct part,
but I said I wasn't willing to pay more than $60 in any event.

So I'm back to square one, and would *really* appreciate a circuit
diagram for a rectifier/regulator for a 2-phase alternator suitable for
this application if anyone has one.

Technically, I think you have a 1-phase generator. Alternator implies
that there is a rotor/field winding that needs voltage applied. Since
both wires look identical, I think you have a single stator coil and a
magnet as the rotor instead of a rotor field winding.

Many motorcyles have a 1 or 3 phase version of this which is why I
suggested that a regulator/rectifier off a motorcyle might work well.
You would need to add a small battery. The catch is figuring out which
model/year to use, but once that was figured out it'd just be a matter
of wiring it in place.

1978 and later Kawasaki KZs have a 3-phase generator and the regulator
would probably work. It'd be a matter of hooking up the yellow wires
and two wires to the battery. In fact, I had an extra regulator for
my 78 KZ650 until I sold it on eBay for $20 last year.

Internally, the module has two sections. The rectifier portion had a
series of diodes to rectify the voltage and feed it to the battery
which smoothed out the high voltage spikes. The regulator part simply
shorted the yellow wires from the generator to ground when the battery
voltage was high enough. I believe it used a triac or scr to
accomplish this. Sorry I don't have a specific schematic. The
motorcycle repair manual just has a block drawing.


-Chris

 

[[email protected]]

BINGO! I just took a few minutes to Google and came across this page.
It looks like exactly what you need and has a circuit schematic. To
change this to a 1-phase circuit, delete R1, SCR3, D4, and D7. Just
make sure things are properly heat sinked.

http://www.takisnet.org/~abayko/vreg.pdf

-Chris

 

[Sunny]

Hi Sunny...

By the strangest of coincidences I fished awhile
with my dealer friend today... (bought a new boat
and motor from him, he and his family delivered it to
the cottage 'cause it's a bit too heavy for my car
to pull)

We discussed your situation... he said though he's
not a Merc dealer, they do service them and do have
manuals. And even if not they can get copies by
contra with one of the merc dealers....

He said you'd need something that sounded like
a rotor/stator plate (expensive) that would
generate the rough too high 12 volts. Then you
need to buy a rectifier/regulator device (expensive
and not long lasting).

I told him you already had two wires coming out,
that they produced up to 160 volts at high rev's.
He looked concerned and confused, asked if they
were yellow? Concluded by saying leave them alone,
they are ignition only, and only brought out for test
purposes.

Yes, they are yellow - but my dealer insists they are connected to a
pair of coils in the stator, independent of the ignition system, which
make up a 2-phase alternator with the other ends of the coils grounded.
He says there is only one stator listed for my motor, same one for both
manual and electric start models, as confirmation.

He too suggested that you'd be best advised to
just use a battery and charge it once or twice a
season.

Apparently he's right, because the outboard manufacturers do not provide
a system which allows for charging a small battery for lighting only -
if you want your battery charged, you are expected to pay an extra $600
for the electric start model.

Though he (Larry Wadge - owner of AVO marine) is
busy this time of year, if you like I'll ask him
when next we meet if he'd mine photocopying the
relevant page(s) for you. It might take time,
though.

I doubt the relevant pages will include a circuit diagram of the
regulator/rectifier, and I don't want Larry's time wasted on my account,
but many thanks for offering.

Regards,

Sunny

 

[Sunny]

BINGO! I just took a few minutes to Google and came across this page.
It looks like exactly what you need and has a circuit schematic. To
change this to a 1-phase circuit, delete R1, SCR3, D4, and D7. Just
make sure things are properly heat sinked.

http://www.takisnet.org/~abayko/vreg.pdf

-Chris

Thanks Chris - it looks promising. As I noted in an earlier post, my
dealer is adamant that the two yellow wires are the output of a 2-phase
alternator with the other ends of the coils grounded. However it seems
to me that is irrelevant, it should still work if I delete SCR3 and
associated components, and connect the two stator coils to the remaining
winding inputs, right?

Sunny

 

[Asimov]

"Sunny" bravely wrote to "All" (05 Jul 04 21:55:24)
--- on the heady topic of "Re: Rectifier/Regulator circuit for an outboard motor?"

He too suggested that you'd be best advised to
just use a battery and charge it once or twice a
season.

Su> Apparently he's right, because the outboard manufacturers do not
Su> provide a system which allows for charging a small battery for
Su> lighting only - if you want your battery charged, you are expected to
Su> pay an extra $600 for the electric start model.

Though he (Larry Wadge - owner of AVO marine) is
busy this time of year, if you like I'll ask him
when next we meet if he'd mine photocopying the
relevant page(s) for you. It might take time,
though.

Su> I doubt the relevant pages will include a circuit diagram of the
Su> regulator/rectifier, and I don't want Larry's time wasted on my
Su> account, but many thanks for offering.

Su> Regards,

Su> Sunny

I was just reading about a system used to generate power in sailboats.
It is some sort of small generator on the end of a pole skimming just
below the water surface. Just large enough to charge a battery and
sometimes supplemented by a small pv panel (when there is no wind).

I'm sure it couldn't be that difficult to put a small pm motor in a
water tight casing with a prop on the end of it. This isn't a new
idea, IIRC it was also used in airplanes at some point in time. Well
at least it is something else to consider thinking outside the box, so
to speak.

Asimov
******

.... Now touch these wires to your tongue!

 

[[email protected]]

Thanks Chris - it looks promising. As I noted in an earlier post, my
dealer is adamant that the two yellow wires are the output of a 2-phase
alternator with the other ends of the coils grounded. However it seems
to me that is irrelevant, it should still work if I delete SCR3 and
associated components, and connect the two stator coils to the remaining
winding inputs, right?

Sunny

WHOOPS!
Looking at the diagram again, I think diodes D5, D6, and D7 are shown
backwards. They should be turned around

It should be trivial with a multimeter to figure out if it's two coils
with a ground connection between them. If that's the case, then yes
can still delete the SCR3 and associated parts.

You can substitute a standard ac regulator instead of individual
diodes. Same thing, a tad more expensive usually, but simpler to
wire.


-Chris