On Wed, 29 Dec 2004 16:17:01 -0800, Frank Gilliland
wrote:

On Wed, 29 Dec 2004 17:55:16 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

Frank Gilliland wrote in
m:

Current equalizing resistors is another way to do it. It's common
practice in SS audio amps to use emitter resistors to equalize the
currents between parallel transistors. But I would hesitate using them
with modern alternators because I don't know how it would screw with
the regulators -- some have a local sense line and others have a
remote sense line -- a resistor in the load might send the regulator
into seizures.


Frank it is very easy a single regulator will control the field voltage on
both alternators. This way they would run the same and share the "Load"


I thought about that, but wouldn't the rotors need to be locked in
phase?


Phase? The control voltage is DC, the outputs are DC, am I missing
something? I know that the output of an alternator isn't "pure' DC,
but it will never be 180 degrees out.

On Thu, 30 Dec 2004 16:46:42 GMT, Lancer wrote in
. com:

On Wed, 29 Dec 2004 16:17:01 -0800, Frank Gilliland
wrote:

On Wed, 29 Dec 2004 17:55:16 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

Frank Gilliland wrote in
:

Current equalizing resistors is another way to do it. It's common
practice in SS audio amps to use emitter resistors to equalize the
currents between parallel transistors. But I would hesitate using them
with modern alternators because I don't know how it would screw with
the regulators -- some have a local sense line and others have a
remote sense line -- a resistor in the load might send the regulator
into seizures.


Frank it is very easy a single regulator will control the field voltage on
both alternators. This way they would run the same and share the "Load"


I thought about that, but wouldn't the rotors need to be locked in
phase?


Phase? The control voltage is DC, the outputs are DC, am I missing
something? I know that the output of an alternator isn't "pure' DC,
but it will never be 180 degrees out.


Auto alternators are three-phase alternators. As such, the rectified
output never drops to zero, but it does have significant ripple. The
regulator obviously controls the DC component. So I guess the question
is if the regulator also smooths the ripple. If it does then parallel
alternators must be locked in phase. But if it just controls the DC
component then current equalizing resistors will do the job (although
I would think about putting a ripple filter on the sense lines).

http://www.geocities.com/mopedzadumd...?1082158996910

"Lancer" wrote in message
ews.com...
On Wed, 29 Dec 2004 16:17:01 -0800, Frank Gilliland
wrote:

On Wed, 29 Dec 2004 17:55:16 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

Frank Gilliland wrote in
:

Current equalizing resistors is another way to do it. It's common
practice in SS audio amps to use emitter resistors to equalize the
currents between parallel transistors. But I would hesitate using them
with modern alternators because I don't know how it would screw with
the regulators -- some have a local sense line and others have a
remote sense line -- a resistor in the load might send the regulator
into seizures.


Frank it is very easy a single regulator will control the field voltage
on
both alternators. This way they would run the same and share the "Load"


I thought about that, but wouldn't the rotors need to be locked in
phase?


Phase? The control voltage is DC, the outputs are DC, am I missing
something? I know that the output of an alternator isn't "pure' DC,
but it will never be 180 degrees out.

Alternators deliver 3 phase, approximately 120 volts output at working RPM.

U Know Who wrote:


"Lancer" wrote in message
ews.com...
On Wed, 29 Dec 2004 16:17:01 -0800, Frank Gilliland
wrote:

On Wed, 29 Dec 2004 17:55:16 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

Frank Gilliland wrote in
m:

Current equalizing resistors is another way to do it. It's common
practice in SS audio amps to use emitter resistors to equalize the
currents between parallel transistors. But I would hesitate using them
with modern alternators because I don't know how it would screw with
the regulators -- some have a local sense line and others have a
remote sense line -- a resistor in the load might send the regulator
into seizures.


Frank it is very easy a single regulator will control the field voltage
on
both alternators. This way they would run the same and share the "Load"


I thought about that, but wouldn't the rotors need to be locked in
phase?


Phase? The control voltage is DC, the outputs are DC, am I missing
something? I know that the output of an alternator isn't "pure' DC,
but it will never be 180 degrees out.

Alternators deliver 3 phase, approximately 120 volts output at working
RPM.

Yes I know that, The output (at least on most automotive applications is
DC.)
I have seen modifed alternators with 3 transformers on them to provide
higher voltages for B+ for transmitters.

On Fri, 31 Dec 2004 00:40:51 GMT, Lancer wrote:

U Know Who wrote:


"Lancer" wrote in message
ews.com...
On Wed, 29 Dec 2004 16:17:01 -0800, Frank Gilliland
wrote:

On Wed, 29 Dec 2004 17:55:16 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

Frank Gilliland wrote in
om:

Current equalizing resistors is another way to do it. It's common
practice in SS audio amps to use emitter resistors to equalize the
currents between parallel transistors. But I would hesitate using them
with modern alternators because I don't know how it would screw with
the regulators -- some have a local sense line and others have a
remote sense line -- a resistor in the load might send the regulator
into seizures.


Frank it is very easy a single regulator will control the field voltage
on
both alternators. This way they would run the same and share the "Load"


I thought about that, but wouldn't the rotors need to be locked in
phase?


Phase? The control voltage is DC, the outputs are DC, am I missing
something? I know that the output of an alternator isn't "pure' DC,
but it will never be 180 degrees out.

Alternators deliver 3 phase, approximately 120 volts output at working
RPM.

Yes I know that, The output (at least on most automotive applications is
DC.)
I have seen modifed alternators with 3 transformers on them to provide
higher voltages for B+ for transmitters.

BTW Randy, I wasn't trying to be a smart ass with my answer.

"Lancer" wrote in message
ews.com...
On Fri, 31 Dec 2004 00:40:51 GMT, Lancer wrote:

U Know Who wrote:


"Lancer" wrote in message
ews.com...
On Wed, 29 Dec 2004 16:17:01 -0800, Frank Gilliland
wrote:

On Wed, 29 Dec 2004 17:55:16 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

Frank Gilliland wrote in
news:q9i5t09kfa8oceo2bsc8sp2fri7hl2d4bo@4ax. com:

Current equalizing resistors is another way to do it. It's common
practice in SS audio amps to use emitter resistors to equalize the
currents between parallel transistors. But I would hesitate using
them
with modern alternators because I don't know how it would screw with
the regulators -- some have a local sense line and others have a
remote sense line -- a resistor in the load might send the regulator
into seizures.


Frank it is very easy a single regulator will control the field
voltage
on
both alternators. This way they would run the same and share the
"Load"


I thought about that, but wouldn't the rotors need to be locked in
phase?


Phase? The control voltage is DC, the outputs are DC, am I missing
something? I know that the output of an alternator isn't "pure' DC,
but it will never be 180 degrees out.

Alternators deliver 3 phase, approximately 120 volts output at working
RPM.

Yes I know that, The output (at least on most automotive applications is
DC.)
I have seen modifed alternators with 3 transformers on them to provide
higher voltages for B+ for transmitters.

BTW Randy, I wasn't trying to be a smart ass with my answer.

I didn't take it that way. NP!

On Fri, 31 Dec 2004 00:52:30 GMT, Lancer wrote in
:

snip
I still don't quite see why you would need to have the alternators run in
phase. If you were taking the 3 phase out before rectifying it, yes.


The problem is if they slip out of phase then the ripple from each
will be mixed. At 60 degrees shift the ripple between the two will be
twice that of one alternator. That can't be good for a battery. Also,
as the alternators continue to rotate against each other the output
will change from very smooth to twice as bumpy, and will do so at a
very low frequency. The problem here lies with how the regulator
senses the DC output. It's doubtful that the regulator will see true
RMS, so the result is that you will get a low frequency variation of
the DC output. Another problem is how that variation will be fed back
to the rotors from the regulator..... but that's all moot:

I did a little research and found out that only a few alternators have
regulation fast enough to smooth the ripple. That's good news because
there is no need to use a single regulator or to lock the phase of the
alternators. All that's needed is current equalization with resistors.

And for the sake of mentioning it, I also found out that most of the
newer alternators (like the Delco CS130 in my truck) use a 'switching'
type regulation scheme, which may be why alternator whine in the radio
is becoming much more common.

On Thu, 30 Dec 2004 17:39:10 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

Frank Gilliland wrote in
:

On Thu, 30 Dec 2004 14:59:40 GMT, Lancer wrote in
:

Frank Gilliland wrote:

On Wed, 29 Dec 2004 17:55:16 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

Frank Gilliland wrote in
om:

Current equalizing resistors is another way to do it. It's common
practice in SS audio amps to use emitter resistors to equalize the
currents between parallel transistors. But I would hesitate using
them with modern alternators because I don't know how it would
screw with the regulators -- some have a local sense line and
others have a remote sense line -- a resistor in the load might
send the regulator into seizures.


Frank it is very easy a single regulator will control the field
voltage on
both alternators. This way they would run the same and share the
"Load"


I thought about that, but wouldn't the rotors need to be locked in
phase?

Phase? The control voltage is DC, the output is DC, am I missing
something?


The control (field) current is fluctuating DC, isn't it? Isn't that
how the regulator smooths the output (which would be fluctuating DC if
the field current was steady)?


When the rectified DC from each of the three-phase windings is added
together, the peaks overlap to produce a much cleaner DC with much less
ripple. Lead-acid auto batteries last longer when charged with pure DC
than high ripple rectified DC. Three-phase windings were designed into
alternators to produce DC of great purity.


When you quote someone else it's good practice to cite the source:

http://mysite.verizon.net/res00d4r/a...or_Theory.html

On Fri, 31 Dec 2004 03:24:29 GMT, Lancer wrote in
. com:

On Thu, 30 Dec 2004 18:30:21 -0800, Frank Gilliland
wrote:

On Fri, 31 Dec 2004 00:52:30 GMT, Lancer wrote in
:

snip
I still don't quite see why you would need to have the alternators run in
phase. If you were taking the 3 phase out before rectifying it, yes.


The problem is if they slip out of phase then the ripple from each
will be mixed. At 60 degrees shift the ripple between the two will be
twice that of one alternator. That can't be good for a battery. Also,
as the alternators continue to rotate against each other the output
will change from very smooth to twice as bumpy, and will do so at a
very low frequency. The problem here lies with how the regulator
senses the DC output. It's doubtful that the regulator will see true
RMS, so the result is that you will get a low frequency variation of
the DC output. Another problem is how that variation will be fed back
to the rotors from the regulator..... but that's all moot:

True, I just thought that the battery saw anywhere from 13 to 15 or
16 from the alternator that it wouldn't be all that big a deal.


Feed a charged battery with more than 14 volts or so and it will go
dry very quickly.


I did a little research and found out that only a few alternators have
regulation fast enough to smooth the ripple. That's good news because
there is no need to use a single regulator or to lock the phase of the
alternators. All that's needed is current equalization with resistors.

And for the sake of mentioning it, I also found out that most of the
newer alternators (like the Delco CS130 in my truck) use a 'switching'
type regulation scheme, which may be why alternator whine in the radio
is becoming much more common.


My truck also has that. Mine went out last year, it took three tries
to get a rebuilt replacement that would work correctly. I guess they
have different regulators that sense starting or resting voltage.


Beats me, but from what I have found out so far I'm about ready to
swap mine out for a 10SI I bought as a spare for another truck. It has
a lower current rating, but I've never had one go out on me (hence the
reason I still have the spare).

Psychiatrist to keyclowns wrote:
Not needed by anyone operating legally.

Really? I need two 150A alternators... and I operate quite legally, from
160 meters to 10 meters, plus 6, 2, 70cm, 1G, and 10G.

You might want to be a bit more succinct.

Besides, he might need them to power audio amps for his car stereo,
searchlights, lightbars, etc..

I didn't see any mention of what they'd be used for.. he just asked if
it'd be worth it.

-SSB

Programbo5 wrote:
Not needed by anyone operating legally.


Now you see right away you are thinking something negative..Since this is a
CB newsgroup maybe a lot of OTR truckers read here and might need a big
alternator for thier Freightliner or Peterbuilt



The internet is more than a global pornography network
Heh. There isn't a "u" in Peterbilt. ::grin::

Twistedhed wrote:
From: (Programbo5)
I have a chance to pick up like 8 used 105 amp Leece Nevilles for $15 a
piece..Is this to low of an output to make it worth grabbing them and
attempting to turn around and sell them?..Thanks
The internet is more than a global pornography network
_
Can you refurbish them yourself or do you know someone that can help
you? If you answer yes to either question, grab them. Otherwise, they
could be scrap value only.


If he doesn't want them, I wouldn't mind two or three... Got ideas for
some more power in the truck, and having a couple to rework would be fun.

-SSB

On Thu, 30 Dec 2004 23:31:51 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

snip
When you quote someone else it's good practice to cite the source:

http://mysite.verizon.net/res00d4r/a...ternator_Theor
y.html



Sorry frank i didnt use that web page as my source.


http://members.1stconnect.com/anozir...nator/alternat
or.htm


Same difference. Author unknown, date unknown. Anonymous authority.

The problem is that the output is far from being "DC of great purity".
The battery is used as a capacitor to smooth the ripple, just like the
filter capacitor in a power supply.


With all this discussion I'm getting ideas for a different type of
alternator: one output for the electrical system and another for an
independent battery charging system. And the battery charging system
could have outputs for both starting and deep-cycle batteries, with
remote temperature control and optional desulfator......... Ok, I'm
dreaming. But I'm definitely going to build an external regulator and
trash that micro-chip garbage that's in it now.

From: (SideBand)
Twistedhed wrote:
From: (Programbo5)
I have a chance to pick up like 8 used 105 amp Leece Nevilles for $15 a
piece..Is this to low of an output to make it worth grabbing them and
attempting to turn around and sell them?..Thanks
=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0The internet is more than a global
pornography network
_
Can you refurbish them yourself or do you know someone that can help
you? If you answer yes to either question, grab them. Otherwise, they
could be scrap value only.

If he doesn't want them, I wouldn't mind two or
three... Got ideas for some more power in the

truck, and having a couple to rework would be

fun.

-SSB

Go for it! I'm still wating for you to get that all-too-rare trip down
to the southland and get in my receive.

On Fri, 31 Dec 2004 15:26:39 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

snip
Use a Pulse width modulator and some fet's


......uh, I don't think so. Efficiency is far less important to me than
eliminating possible RFI or regulator failure. I have a lot of MJ11028
power Darlingtons and a pair of those should do the job just fine.

On Sat, 01 Jan 2005 12:05:33 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

Frank Gilliland wrote in
:

On Fri, 31 Dec 2004 15:26:39 -0600, itoldyouiamnotiamnotgeorge
wrote in
:

snip
Use a Pulse width modulator and some fet's


.....uh, I don't think so. Efficiency is far less important to me than
eliminating possible RFI or regulator failure. I have a lot of MJ11028
power Darlingtons and a pair of those should do the job just fine.



so why would a pwm and some fets on the outputs be any different. I have
never seen rfi or failure due to these components, and a good designer
would add filter caps to the circuit where needed.

PWM tl494 and some P channel fet's would work flawlessly.

http://focus.ti.com/docs/prod/folders/print/tl494.html


Why would I convert from a switching regulator to another switching
regulator? That doesn't make sense. I want linear regulation because
switching regulators generate square waves; i.e, noise. Also, FETs in
switching regulators aren't just FETs, they're MOSFETs, and I wouldn't
trust a MOSFET in any harsh environment, let alone under the hood of
my truck.

And BTW, nothing works "flawlessly", especially MOSFET's.


Or you could go with 1-tip36c which would be more than adequate you
wouldn't need 2 MJ11028's


First, a single MJ11028 can handle the same collector current as -two-
TIP36C's. Second, the hfe of the TIP36C is 25 compared to a minimum of
400 for the MJ11028, so the latter doesn't require a power transistor
to drive it. Third, the transistion frequency of the TIP36C is 3MHz,
meaning it can be prone to oscillation -especially- in any application
where surges or spikes can occur; Darlingtons barely work above audio
frequencies. And most important, I don't have a TIP36C but I -do- have
a stock of MJ11028's.