Ferite core?

a cigarette lighter male plug on one end and a 3.5 mm plug on the other. However, each line has a heavy, hefty cylinder thereon that I believe is probably a ferite core. What's the purpose of these things?

From your description, those are for EMI suppression.

Ed

Ivan Vegvary wrote in news:27929501.536.1317775373580.JavaMail.geo-discussion-forums@prma7:

Stopping high-frequency interference from leaking in or out. The cable otherwise will act as an arial.

"Ivan Vegvary"

Just purchased a 12 volt adapter for my CPAP breathing machine. It consist of a cigarette lighter male plug on one end and a 3.5 mm plug on the other. However, each line has a heavy, hefty cylinder thereon that I believe is probably a ferite core. What's the purpose of these things?

Even without them, not much would escape to the outside world if used inside a car as intended - but easily enough to ruin AM radio reception in the same car in weak signal areas.

.... Phil

The primary reason is probably to protect the CPAP from the highest frequency conducted emissions produced by the car power system.

--Winston

"Winston the Wanker "

Piss off - fool.

.... Phil

That's better. Thanks Phil.

--Winston

AARGH! _AERIAL_. "Arial" is a font.

And, yes, they're to keep the ambient electromagnetic noise out of the circuit. ;-)

Hope This Helps! Rich