I am not a big electronics chap so this may be an obvious answer but..

I drive a BMW R1100RS motorcycle and the alternator has hit the dirt,
removing the voltage regulator/brush unit
(http://dazhong.en.alibaba.com/produc...Regulator.html
) and testing with an ohm meter I can the see the To-3 regulator has
failed (high continuity between input and ground). A new unit cost
$120 but I'd like to repair if possible.

The battery is the usual 12v and the running voltage is 14v. The
regulator regulates the voltage on the slip rings which excites the
rotor, but I assume the voltage for the rotor varies with the load, so
if the bus voltage is 14v more voltage is sent to the rotor. So why
kind of regulator is this and can I find one in Mouser?

Thanks and cheers,

On 3 Feb 2006 12:30:20 -0800, "jcpearce"
wrote:

I am not a big electronics chap so this may be an obvious answer but..

I drive a BMW R1100RS motorcycle and the alternator has hit the dirt,
removing the voltage regulator/brush unit
(http://dazhong.en.alibaba.com/produc...Regulator.html
) and testing with an ohm meter I can the see the To-3 regulator has
failed (high continuity between input and ground). A new unit cost
$120 but I'd like to repair if possible.

The battery is the usual 12v and the running voltage is 14v. The
regulator regulates the voltage on the slip rings which excites the
rotor, but I assume the voltage for the rotor varies with the load, so
if the bus voltage is 14v more voltage is sent to the rotor. So why
kind of regulator is this and can I find one in Mouser?

Thanks and cheers,

I have a '72 R75/5. It had an old mechanical reg (still excited
field type - same as used in most cars and your RS)

I replaced it with a solid state one I found/adapted from an auto
manual. Two transistors, 5 fixed resistors, one variable (so I can
set the limit) one zener diode and a couple of rectifier diodes.

I'm not aware of anyone marketing a TO3 style regulator for lead acid
batteries but I seem to remember GM alternators had one that fit on
the brush housing (so it would be three connections, ala TO-3)

My homemade one uses four wires - one to ignition (but it works with
that tied to the alternator output - used it on a Toyota Land Cruiser
in that mode), one to ground, one to the alternator diodes (diode
board in the R75 with a set of 3 diodes that only fed the regulator),
and an wire for the slip rings.

My bike has a "charge" indicating lamp on it. When the alternator is
just starting - the current to excite the field comes through the
idiot light - when the alternator is spinning, and generating voltage,
the power for the slip rings comes from the diodes, turning the idiot
light off.

I can supply the schematic of what I used.. You'd need a modicum of
electronics knowledge (ability to observe polarity of the diodes,
connect the semiconductors, solder and package it (no heat sink
necessary if you use a TO-3 or TO-220 or TO-66 or similar transistor
for the output. I used a pair of 2N3054 transistors and heat-sinked
the pass transistor - but it never got mildly warm.

Mine has worked since 1973 - the transistors are exposed and I've been
varnishing them to slow the rust. I have a 81 Honda 750 and it uses
the same type alternator - I rewound the rotor when it shorted -
that's a lot harder than building a simple regulator.

I can scan and send the schematic if you want to try building one,
remove capital Xs and treat like an email ady.

XganethX(at)movemail(dot)com
--

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----

default wrote in message
...
On 3 Feb 2006 12:30:20 -0800, "jcpearce"
wrote:

I am not a big electronics chap so this may be an obvious answer but..

I drive a BMW R1100RS motorcycle and the alternator has hit the dirt,
removing the voltage regulator/brush unit
(http://dazhong.en.alibaba.com/produc...Regulator.html
) and testing with an ohm meter I can the see the To-3 regulator has
failed (high continuity between input and ground). A new unit cost
$120 but I'd like to repair if possible.

The battery is the usual 12v and the running voltage is 14v. The
regulator regulates the voltage on the slip rings which excites the
rotor, but I assume the voltage for the rotor varies with the load, so
if the bus voltage is 14v more voltage is sent to the rotor. So why
kind of regulator is this and can I find one in Mouser?

Thanks and cheers,

I have a '72 R75/5. It had an old mechanical reg (still excited
field type - same as used in most cars and your RS)

I replaced it with a solid state one I found/adapted from an auto
manual. Two transistors, 5 fixed resistors, one variable (so I can
set the limit) one zener diode and a couple of rectifier diodes.

I'm not aware of anyone marketing a TO3 style regulator for lead acid
batteries but I seem to remember GM alternators had one that fit on
the brush housing (so it would be three connections, ala TO-3)

My homemade one uses four wires - one to ignition (but it works with
that tied to the alternator output - used it on a Toyota Land Cruiser
in that mode), one to ground, one to the alternator diodes (diode
board in the R75 with a set of 3 diodes that only fed the regulator),
and an wire for the slip rings.

My bike has a "charge" indicating lamp on it. When the alternator is
just starting - the current to excite the field comes through the
idiot light - when the alternator is spinning, and generating voltage,
the power for the slip rings comes from the diodes, turning the idiot
light off.

I can supply the schematic of what I used.. You'd need a modicum of
electronics knowledge (ability to observe polarity of the diodes,
connect the semiconductors, solder and package it (no heat sink
necessary if you use a TO-3 or TO-220 or TO-66 or similar transistor
for the output. I used a pair of 2N3054 transistors and heat-sinked
the pass transistor - but it never got mildly warm.

Mine has worked since 1973 - the transistors are exposed and I've been
varnishing them to slow the rust. I have a 81 Honda 750 and it uses
the same type alternator - I rewound the rotor when it shorted -
that's a lot harder than building a simple regulator.

I can scan and send the schematic if you want to try building one,
remove capital Xs and treat like an email ady.

XganethX(at)movemail(dot)com

I also would like a scan of schematic if you would. Can send direct to
hiviewNOSPAM@ bresnan.net Of course leave out the no spam TIA Warren





----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet
News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption
=----

I suggest you ask this question on sci.electronics.design.

They will design a new one for you...

Mark

jcpearce wrote:
I am not a big electronics chap


Are you in England? If you were in the states, I'd suggest calling
National Automotive Lines in Shelbyville, Indiana. They do not have a
website. They sell car parts, but the link you provided suggests that
the brush-regulator assembly is used in a variety of automotive
alternators, not just bike regulators.

The toll-free number is 1-800-428-4300. The toll-free fax number is
1-888-442-9222. It's a great outfit to do business with.

jcpearce wrote:
I am not a big electronics chap so this may be an obvious answer but..

I drive a BMW R1100RS motorcycle and the alternator has hit the dirt,
removing the voltage regulator/brush unit
(http://dazhong.en.alibaba.com/produc...Regulator.html
) and testing with an ohm meter I can the see the To-3 regulator has
failed (high continuity between input and ground). A new unit cost
$120 but I'd like to repair if possible.

The battery is the usual 12v and the running voltage is 14v. The
regulator regulates the voltage on the slip rings which excites the
rotor, but I assume the voltage for the rotor varies with the load, so
if the bus voltage is 14v more voltage is sent to the rotor. So why
kind of regulator is this and can I find one in Mouser?

Thanks and cheers,



Have you looked online? Volvo and Saab both use a very similar Bosch
alternator with the onboard regulator, the last time I needed one it was
only about $30 online though the dealer charges around $170.

On 3 Feb 2006 12:30:20 -0800, "jcpearce"
wrote:

I am not a big electronics chap so this may be an obvious answer but..

I drive a BMW R1100RS motorcycle and the alternator has hit the dirt,
removing the voltage regulator/brush unit
(http://dazhong.en.alibaba.com/produc...Regulator.html
) and testing with an ohm meter I can the see the To-3 regulator has
failed (high continuity between input and ground). A new unit cost
$120 but I'd like to repair if possible.

The battery is the usual 12v and the running voltage is 14v. The
regulator regulates the voltage on the slip rings which excites the
rotor, but I assume the voltage for the rotor varies with the load, so
if the bus voltage is 14v more voltage is sent to the rotor. So why
kind of regulator is this and can I find one in Mouser?

Thanks and cheers,

If it's a modular unit it's a simple matter of buying a new one.
Usually around 20-30 bucks US.(unless you purchase direct from the
dealer then of course it may cost more.)

jcpearce wrote:

I am not a big electronics chap so this may be an obvious answer but..

I drive a BMW R1100RS motorcycle and the alternator has hit the dirt,
removing the voltage regulator/brush unit
(http://dazhong.en.alibaba.com/produc...Regulator.html
) and testing with an ohm meter I can the see the To-3 regulator has
failed (high continuity between input and ground). A new unit cost
$120 but I'd like to repair if possible.

The battery is the usual 12v and the running voltage is 14v. The
regulator regulates the voltage on the slip rings which excites the
rotor, but I assume the voltage for the rotor varies with the load, so
if the bus voltage is 14v more voltage is sent to the rotor. So why
kind of regulator is this and can I find one in Mouser?

Thanks and cheers,

Hi...

Your use of the word "chap" leads me to believe you're
probably somewhere in the UK, so don't know how helpful
this might be.... but...

Here we can buy rebuild kits for virtually any alternator
for about 20 dollars cdn. They come with everything,
the regulator of course, as well as new brushes, springs,
bearings, etc.

Our most "famous" source is Canadian Tire, perhaps you have
something equivalent over there?

Take care.

Ken

I have english background, but I live in the States.
I have checked Kragen's and the part retails for $110. Amazing as I
bought a whole rebuit alternator for my experimental plane for $20
(with core). Probably some generic american brand would be quite
cheaper. I can get the actual BMW part for $85 so I will probably just
do that vs run around on an experiment I soldered together. A new BMW
alternator costs $575, talk about bending over.

jcpearce wrote:
I have english background, but I live in the States.
I have checked Kragen's and the part retails for $110. Amazing as I
bought a whole rebuit alternator for my experimental plane for $20
(with core). Probably some generic american brand would be quite
cheaper. I can get the actual BMW part for $85 so I will probably just
do that vs run around on an experiment I soldered together. A new BMW
alternator costs $575, talk about bending over.



Check out www.alloembmwparts.com, it crosses to the same site I get
Volvo and Saab parts from. I don't know what model your BMW is but they
list the same Bosch regulator/brushpack that many other European cars
use and it's $26 aftermarket or $44 OEM. That place has great service
too, I've ordered items several times and had them show up within 48
hours with standard shipping.

Not that it's relevant, but I used to own a BMW, a 1970 1600. I
eventually installed a Bosch alternator from an Opel in the BMW. The
only difference was in the mounting ears on the exterior of the
alternator. The internals were identical.

I suspect that interchangeability is still the rule, and that if you
order the Bosch alternator as a Volkswagen part or an Opel part, for
example, you will pay less for it than you would had you ordered from
the BMW dealer.

In article .com,
Beloved Leader wrote:
I suspect that interchangeability is still the rule, and that if you
order the Bosch alternator as a Volkswagen part or an Opel part, for
example, you will pay less for it than you would had you ordered from
the BMW dealer.

Or get an exchange unit from a Bosch dealer. Or indeed an exchange unit
from any reputable source.

--
*Organized Crime Is Alive And Well; It's Called Auto Insurance.

Dave Plowman London SW
To e-mail, change noise into sound.

On 5 Feb 2006 17:38:12 -0800, "jcpearce"
wrote:

I have english background, but I live in the States.
I have checked Kragen's and the part retails for $110. Amazing as I
bought a whole rebuit alternator for my experimental plane for $20
(with core). Probably some generic american brand would be quite
cheaper. I can get the actual BMW part for $85 so I will probably just
do that vs run around on an experiment I soldered together. A new BMW
alternator costs $575, talk about bending over.

NEVER buy from the dealer. Go to any decent import parts store and get
the beck/Arnley aftermarket part. Or Bosch.