Help with polarity

[Stephen Shauger]

I would appreciate help with a problem.

I am trying to install a "CD to Cassette Adapter" and a "Portable CD
Power Adapter" to my car which has a tape deck.

The Power Adapter (Phillips #72488) says to set the polarity on the
plug so that the word tip lines up with either the "+" or the "-" if
the polarity of the portable CD player's polarity is positive or
negative.

My portable CD player (Sony Discman D-111) has center-point positive
polarity. I.e. the diagram looks like this.

+ ---0)--- -

So my question is: Is "center-point positive" the same as "positive"?
In other words, when the instructions on my power adapter refer to
positive polarity, are they refering to the center point or to the
outer wall.

Please reply to email shaugville@juno.com

Thank you so much for your help.

Stephen

 

[Sir Charles W. Shults III]

"Stephen Shauger" <shaugville@juno.com> wrote in message
news:71f58dcb.0308182054.6e98dc1f@posting.google.com...
<snip>

So my question is: Is "center-point positive" the same as "positive"?

Yes. It is exactly what it says. The center is positive. The wall is
negative.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip

 

[JeffM]

So my question is:
Is "center-point positive" the same as "positive"?
Aligning the correct polarity symbol
with the side of the plug receptacle marked "tip",
...do they mean measured from the wall?
Stephen Shauger

Everybody needs to start using the same terminology.
On a 1/4" phone jack, starting from the center,
it goes tip, ring, sleeve.
On smaller phone jacks, too small for 3 elements,
it's tip, sleeve.

I've never heard a standard call-out on coaxial connectors
which have a hollow center on the male plug.
I say center conductor, sleeve.

"Wall" is never used.

That said, things are generally referenced from the sleeve,
since it is most likely to touch the chassis or "ground".
So, yes, you called it right.

 

[Rich Grise]

shaugville@juno.com (Stephen Shauger) wrote in message
....

So my question is: When the instructions to my power adapter refer to
"positive" and "negative" polarities with no other context given, do
they mean "center-point positive" and "center-point negative"
polarities? Or do they mean measured from the wall?

Thank you,

Stephen

One way to find out for sure is with a voltmeter.

Cheers!
Rich

 

[Sir Charles W. Shults III]

I think you are analyzing this WAY too hard. Positive is positive, period.
There is only one center point. It can only be negative or positive.

Cheers!

Chip Shults
My robotics, space and CGI web page - http://home.cfl.rr.com/aichip