Re: Mains plugs for 12V DC

In the UK, several 12V accessories I've bought recently had car cigar
lighter plugs fitted - I generally throw these plugs in a box and replace
them with alligator clips. If at some point I wanted to set up a 12V bench
distribution system, I could visit the scrapyard and recover some cigar
lighter sockets from old car dashboards, although they can probably be had
from some component suppliers. IIRC the tyre pump had a 20A fuse and the
240V inverter was something like 35A.

Yep those are them - also at http://tinyurl.com/4qhugc I think they were
used by Telecom in the 70s & 80s in vehicles, trucks, 4wds etc for running
accessories in the field.

"Den"

**This what you mean ?

http://updates.clipsal.com/ClipsalOnline/ProductInformation.aspx?searchMode=cont
ents&first=30&skip=23&contentId=561

**  32 volt,  15 amp AC only it says.

Same issues with tarnishing if used at a lower voltage plus a  NASTY  arcing
issue if used for high current DC.

.....   Phil

Aren't there mains style clipsal/hpm or whatever plugs/sockets with two pins
arranged in a "T" configuration that are intended for DC applications? Maybe
my memory is faulty.

When all you have is a hammer, everything looks like a nail I guess!

Yup. Silly, dangerous, and a poor choice.

So what would other people use as a bench 12V connector for gear?
First thing that springs to mind for me would be XLR connectors. Easy
to mount a strip of those on a panel, and 16A types are readily
available. Get a 4 way type and double up on the pins.

Dave.

"David L. Jones"

** I believe it is totally illegal to use a 240 volt plug or socket for any
other purpose than as a mains connector.

Back when I was a keen model power boat racer, one of the club members
showed up at the lakeside with a new 12V starter motor fitted with a
standard 3 pin mains plug.  He had also fitted a double power point to his
tool box to allow connection to the 12 volt battery he kept inside. The
other socket allowed him to plug in a 12V fuel pump.

Thing is, the guy made his living as an electrician  !!!

Besides being ludicrously  DANGEROUS  the idea will not work reliably as the
brass plug pins and female socket parts are very prone to tarnishing and
when thick enough this tarnish will fully insulate at 12 volts.

One of the reasons why the earth pin has to be nickel plated nowadays.

.....   Phil

Check out this months SC.
Someone has mailed in showing off a 12V power plug system for their
bench - using mains power plugs on all the 12V gear. And he hopes the
idea catches on!

I don't know what's sillier, the idea itself, or SC for actually
publishing it (even with the hammering and warning).

Dave.