In article ,
Major Scott wrote:
They flicker for a reason. If they smoothed the current they might
just as well use DC direct from the battery.

No, provide them with a lower DC voltage to make them dimmer. Say 12V
for brake and 9V for tail.

I'd suggest you look up the Ladybird book of electronics to get a clue
about how LEDs work.

--
*Pride is what we have. Vanity is what others have.

Dave Plowman London SW 12