My recco for a 5W part is based partly because over-rating the part can't
hurt reliability, partly because I find mounting a 5W metal-bodied
resistor easier than a mingy little 1-1/2 - 2W one, and partly because
there's little price penalty in getting the larger part.

Diodes will work admirably well but are less-convenient to mount IMO. I
like my devices fastened down. The tempting mounting hole in a TO-220 is
electrically connected to the diode's innards, whereas a metal-body
resistor's mounting holes are insulated from the electrical bits inside.

But hey -- it comes down to a matter of style; either approach will work
well as long as the guy doing the installation knows what he's doing.

--
Mike "Rocket J Squirrel" Elliott
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
Bend, OR
KG6RCR

On 3/18/2009 3:23 PM David Beierl wrote:

> At 06:06 PM 3/18/2009, Rocket J Squirrel wrote:
>> Get one rated to handle the power, preferably a nice 5W
>> aluminum-bodied one that can be easily bolted to something.
>
> Given P=I^2 R, dissipation at 0.67 amps would be .9 watts -- so a 1
> 1/2 or two watt device should be plenty.
>
> I still favor diode drops for this sort of thing, mostly personal
> prejudice I guess.
>
>   --
> David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
> '89 Po' White Star "Scamp"
>
>