On Tue, 13 Jan 2004 14:23:33 +1300, "Ken Taylor"
wrote:

"Richard G Amirault" wrote in message
...
Steve Nosko wrote:

: "Brian Kelly" wrote in message
: om...
: Backgrounder: Where can one get a decent (i.e., robust)
: general-purpose automotive cigarette lighter plug/tap? [..snip..]
:
: (c) Ignoring the fuse ratings how many amps can auotomotive cigarette
: TNX a bunch, Brian W3RV

: Brian,
: Did you see the one at Radio Shack which looks very much like the one
you
: describe? The binding posts are not full size, but the construction is
: above average.
(snip)

I have one of the Radio Shack binding post plugs as well. It's in one of
my 'go kits' for emergency use.

Frankly, I think you'll also have to worry about the quality of the
cigarette lighter *plug* as well as the output capacity of the jack. As
you mentioned, the tip of these things is spring loaded. When you run a
LOT of amps thru it (the spring) it eventually looses its 'spring' and the
plug becomes unworkable. Remember all the current passes thru the spring
(almost like a fuse) no matter how heavy the actual connecting wire is.

Richard in Boston, MA, USA

I can't see why it should (the spring pass all the current), but even if it
does, can you not insulate either or both end of the spring so that it won't
conduct?

The spring is part of a serial path -- tip spring fuse
wire.

----| ////// [[[[[[[[ -----------------


Insulating the spring would leave you with an open path, just like
cutting the wire.

Frankly I doubt the spring-weakening idea. Some lighter
adapters are just poorly made. I've had some fail to make decent
contact when brand new. I've often had to twist the adapter around
until it made good contact.

I also bought a 110V to 12V (lighter scket) adapter and had
the same problem as in the car. I originally got it to avoid battery
failure problems while uploading firmware to my GPS unit. It still
required a little twisting to make good contact. Same when I later
used it in my office to charge a cellphone.

I have no idea what exactly makes this kind of connector
unreliable, but I've never yet found one that didn't cut out
intermittently.