Cigarette Lighter Adapter- Cessna 172

I could be wrong, but I think Cessna changed the size of the cigarette
lighter plug strictly because so many people were plugging their 12 volt
equipment into the 24 volt aircraft supply and blowing the supply up.

CAUTION. Cessna changed to a 24 volt system sometime in the late 70s/early
80s.

Jim



wrote in message
ups.com...
I've been flying for 7 years now, and a few weeks ago I attempted to
plug in my portable GPS unit into a 2003 172 and ... I couldn't. The
"standard" cigarette adapter has been replaced with a smaller
something. I didn't have time to look too closely as to what the new
outlet is. The GPS was just a backup and I was just going locally .

If anyone else has experienced this, I would appreciate any info on
what adapter I would need to continue to use the "old" cigarette size
plug and who sells them.

Thanks in advance.

All the new (since the line started back up) 172R/S models have
transformers. The outlets are 12V.


On Thu, 3 Aug 2006 16:02:08 -0700, "RST Engineering"
wrote:

I could be wrong, but I think Cessna changed the size of the cigarette
lighter plug strictly because so many people were plugging their 12 volt
equipment into the 24 volt aircraft supply and blowing the supply up.

CAUTION. Cessna changed to a 24 volt system sometime in the late 70s/early
80s.

Jim



wrote in message
oups.com...
I've been flying for 7 years now, and a few weeks ago I attempted to
plug in my portable GPS unit into a 2003 172 and ... I couldn't. The
"standard" cigarette adapter has been replaced with a smaller
something. I didn't have time to look too closely as to what the new
outlet is. The GPS was just a backup and I was just going locally .

If anyone else has experienced this, I would appreciate any info on
what adapter I would need to continue to use the "old" cigarette size
plug and who sells them.

Thanks in advance.

I don't mean to be pedantic, but you can't "transform" a DC voltage;
transformers only work on AC. Do they use a center tap on the battery or a
regulator? If they use a regulator, it had damned well better be a hefty
one to take the slug of current that a cigarette lighter draws.

Jim



"Peter Clark" wrote in message
...
All the new (since the line started back up) 172R/S models have
transformers. The outlets are 12V.

"RST Engineering" wrote:

I don't mean to be pedantic...

LOL

RST Engineering wrote:
I don't mean to be pedantic, but you can't "transform" a DC voltage;
transformers only work on AC. Do they use a center tap on the battery or a
regulator? If they use a regulator, it had damned well better be a hefty
one to take the slug of current that a cigarette lighter draws.

Jim


Only if it is indeed a cigarette lighter and not just a cylindrical 12V
power outlet. My plane has the latter (it just has a plastic cap on
it). I would blow the breaker if I tried to stick a cigarette lighter
in there.

On Thu, 3 Aug 2006 20:05:39 -0700, "RST Engineering"
wrote in
:

If they use a regulator, it had damned well better be a hefty
one to take the slug of current that a cigarette lighter draws.

That would be about 10 amps if it's similar to an automobile.

"RST Engineering" wrote in message ...
:I don't mean to be pedantic, but you can't "transform" a DC voltage;
: transformers only work on AC. Do they use a center tap on the battery or a
: regulator? If they use a regulator, it had damned well better be a hefty
: one to take the slug of current that a cigarette lighter draws.
:
: Jim
:
:
:

Don't they use a voltage divider of some sort?

OK, it's a 'converter'. Not sure exactly what method it uses to
'convert'.

182T Nav III POH, section 7-73,

"12V POWER OUTLET

A power converter located in the cabin side of the firewall, ahead of
the right instrument panel, reduces the aircraft's 28 VDC power to 12
VDC. This converter provides up to 10 amps of power to operate
portable devices such as notebook computers and audio players. The
power output connector (POWER OUTLET 12V -10A) is located on the
center pedestal (refer to Figure 7-2)."

Usual disclaimer about 'see your own aircraft POH for amperage
available etc' applies, but it's also the same in the 172S Nav II and
III packages I've had experience with.

Newer 182T's (2005? and on - I've seen it in an 06) actually have a
rear-seat-mounted cabin power in addition to the one in the front with
it's own on/off switch on the main panel. I wonder if they mounted a
second 'converter' to handle that outlet or if they share somehow. I
was only ferrying it for maintenance and didn't look too closely.

On Thu, 3 Aug 2006 20:05:39 -0700, "RST Engineering"
wrote:

I don't mean to be pedantic, but you can't "transform" a DC voltage;
transformers only work on AC. Do they use a center tap on the battery or a
regulator? If they use a regulator, it had damned well better be a hefty
one to take the slug of current that a cigarette lighter draws.

Jim



"Peter Clark" wrote in message
.. .
All the new (since the line started back up) 172R/S models have
transformers. The outlets are 12V.