DIYbanter - View Single Post - cigarette lighter plug end getting quite warm

Mike Coon[_2_]

In article , says...

I have a cigarette lighter plug and socket rigged up in the house for a
special purpose being drive by a 5VDC, 10 amp supply. The circuit after
the plug is drawing about 7.5 amps. However, upon removing the plug, I
find that it's quite warm almost too hot to touch towards the tip.
Nowhere else throughout the wiring is anything that warm. I am using 14
ga wire throughout and the plug also used 14 ga wires. Is this amount
of heat normal for the plug or is something causing it? Thanks.

Those are a lousy design of plug/socket, skewed because of the
requirement to disconnect when the lighter reaches working temperature.
And of course a bit of excess heat hardly matters in the intended
purpose, either. But the contact area is really too small for high
currents, probably much smaller than the cross section of your wire. If
you actually use it for lighter plugs it may have got a bit dirty from
the sparking, making the contact even worse...