Per Trevor Wilson:
**Do you need heat sinking? 4 Watts is not much power. You could use a 6 Amp
bridge, which can dissipate quite a bit of power, before requiring any heat
sink.

I just checked the specs on the one I ordered. 25 amps/50v.

Sounds like my dinky little hub alternator will barely warm it
up. So much for the heat sink requirement....
--
PeteCresswell