I'm looking for suggestions on bringing 40vdc down to 5vdc
The trick is making it run as cool as possible. I could use a switch mode regulator like a National Semi simple switcher but the normal current requirement is less than 1ma and I thought it might be possible and cheaper to use a 78l05, lm317 or similar. The 80ma requirement is to run a latching relay (approx 8 time per hour) I figure a decent filter cap could take on the load.
Suggestion , advice welcome.