Need diagram for Auto Generator

[[email protected]]

This is probably a bit off topic but does anyone have a wiring diagram
for an old automotive generator and associated regulator? I bought an
old Bobcat skid steer. I was surprised to find that it has a
generator rather than an alternator. THe generator has 2 posts to
connect wires and the regulator has 3. Alternators are easy to trace
the problem, but not generators. This one is not charging. Xan
anyone help?

PS. There used to be a binary newsgroup for wiring schematics. I cant
find it now. What is the group name?

 

[Charlie Bress]

Ury here http://www.secondchancegarage.com/public/83.cfm

 

[Tim]

You might try flashing the generator if it has been sitting a long time.
Just connect the battery directly to the output side of the generator
for a couple of seconds. The power flow thru the windings will setup a
small residual magnetism in the core and the generator will use that to
start the power output going again once it comes up to speed. Regular
use maintains this residual magnetism so you don't need to do it again
unless the unit sits idle for a long time. This was a common problem
with generators.

- Tim -

 

[Dave Plowman (News)]

This is probably a bit off topic but does anyone have a wiring diagram
for an old automotive generator and associated regulator? I bought an
old Bobcat skid steer. I was surprised to find that it has a
generator rather than an alternator. THe generator has 2 posts to
connect wires and the regulator has 3. Alternators are easy to trace
the problem, but not generators. This one is not charging. Xan
anyone help?

The two are fairly similar in principle. Both control the output current
by varying that through the field winding. That is the small terminal. But
when cars used this system the regulator commonly had 5 terminals.
Perhaps the main difference is an alternator is permanently connected to
the battery as the rectifier prevents current flow in the reverse
direction. A dynamo has no diodes, so needs a relay to disconnect it when
its voltage drops below that of the battery, called a cutout. It sounds
like yours has no automatic charge control but only a cutout.

You can do a rough check on the dynamo by disconnecting it and linking the
field and output terminals and connecting to a load - say a headlamp bulb.
The brightness of that will vary with the speed. If it seems to work
connect a DVM set to volts across it and check the polarity is correct. If
no output or the polarity is wrong, leave the bulb connected to the dynamo
and connect the other end to the battery. This will polarize it correctly
by establishing residual magnetism in the field windings.

As regards the regulator - I can only guess. If it is simply a cutout it
should be easy enough to trace the circuit and test. I'd guess there will
be a resistor somewhere else which sets the current through the field
winding.

 

[Franc Zabkar]

This is probably a bit off topic but does anyone have a wiring diagram
for an old automotive generator and associated regulator? I bought an
old Bobcat skid steer. I was surprised to find that it has a
generator rather than an alternator. THe generator has 2 posts to
connect wires and the regulator has 3. Alternators are easy to trace
the problem, but not generators. This one is not charging. Xan
anyone help?

Does this help?
http://groups.google.com/group/sci.electronics.repair/msg/2ba848bd52a45baf?dmode=source

PS. There used to be a binary newsgroup for wiring schematics. I cant
find it now. What is the group name?

alt.binaries.schematics.electronics

- Franc Zabkar

 

[Gary Tait]

[email protected] wrote in 4ax.com:

THe generator has 2 posts to
connect wires and the regulator has 3. Alternators are easy to trace
the problem, but not generators.

Generally, the two terminals on the genrator connenct to two of the
terminals on the regulator, the third termial through the ammeter to the
battery.

There are two types of generator systems, one which the field is conencted
to the armature in the genrator, and grounted to exite it, the other with
the field grounded in the generator, and pulled to the armature line in the
regulator.