On Dec 3, 7:58 am, wrote:
You don't know the half of it.

If it is electronic or even electrical in nature I tend to get
dragooned.

If I wrote about most of the oddities you guys would have me committed
in a rest home.

Up until injured myself on the job, I did a lot of "free lance"
trouble shooting.
Paid very well even if it was almost always weird beyond belief.

A friend is rebuilding a Triumph "Spitfire". While Lucas electric
certainly didn't
invent the short circuit, shoddy design and construction and evil in
general,
they clearly raised it Olympian levels.

Do you know why the Brits drink warm bear?

Lucas made their fridges.

I had never seen a stock car that used two 6 volt batteries in series
to get 12V.
And positive ground...I had managed to avoid dealing with that for 56
years.

My friend is adding a modern alternator and switching to 12V negative
ground.

Would anyone hazard a guess why the starter motor will not have to be
changed?

The wiper and blower motors can have the power leads reversed to get
proper
rotation. But the starter is bonded nicely to the engine frame.

My part of this was trying to explain why he didn't have to replace
the starter
and to design a better wiring loom with enough fuses to offer some
real protection
in the event of a nasty short. Given the switches are stock
Lucas....it stuck me
as a very good idea to add some more fuses.

The radio had died a lifetime ago, kind of sad because it had LW on
it.

So yea, I do post the strangest stuff......I am blessed to live such
an interesting life,

Terry

Hi Terry and others.

To answer your question (if it hasn't already been answered) - If you
reverse the polarity to the charging motor the field will be reversed
but the armature current will also be reversed. In the end the torque
is in the same direction so that the motor spins in the same
direction. I think that most starter motors are probably wound in a
series manner so that the armature current and flux producing current
are the same.

Bearing currents and the resulting failures have been known for quite
some time. That's what happens when you put large dv/dt on a motor.
Bearing failures were well researched at UW-Madison while I was there
in 90s. I suspect a lot of grant money. The motor manufacturers go
out of their way to build motors that are good to go with drives.
Better bearings, and insulation and so forth. I worked in drive
business since 1979 so I've seen the motors get better and better.

I'm going to have to disagree with the notion that high efficiency
motors are lighter than standard efficiency motors. The way to reduce
losses is to increase the copper and steel. Before high efficiency
motors came along people would oversize a motor by a frame size in
order to increase effiency. Smaller motors, fractional - 1hp are
especially inefficient, but cost is usually the driving force rather
than losses.

Now I design power supplies for military radios. I like getting paid
for playing with radios :-)

regards,
NEO