Thanks Colin, Ruben,


hFE doesn't matter much. My DC calculated load is around 350ma @ 12v DC; in
fact, I would be using PWM with variable duty cycle so the current will be
lower than calculated.

MJE340 is an excellent suggestion, it fits the bill but not available @
local supplier (Jameco). I also found MJE200 with Tc of 15W. It is
available @ USD 0.19 each.

I would definitely use a heat-sink.

Thanks.


Chetan Bhargava
http://microz.blogspot.com


On Sun, Oct 20, 2013 at 5:28 AM, Ruben J=F6nsson <ruben@rjjournal.net> wrot=
e:

>
> > On Sat, 19 Oct 2013 22:28:33 -0700, Chetan Bhargava wrote:
> > :: What is a common (abundant and possibly cheap)  5W NPN transistor
> > :: available? My max load voltage is 14V.
> >
>
> Make sure you have a good heat sink. Maximum power dissipation degrades
> linearily to 0W over a certain die temperature. 5W can produce quite a lo=
t
> of
> heat.
>
> /Ruben
>
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> Ruben J=F6nsson
> AB Liros Electronic
> Box 9124
> 200 39 Malm=F6 Sweden
> Tel +46 40142078
> ruben@rjjournal.net
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
> --
> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.