Ubec

[cjcj1949]

What is the usual word for these more efficient becs? Do you get longer flight times by using less current? What rating would be necessary for a standard B400 or TS3D? Anybody used a good cheap one?

[brin]

hi cj this may explain some of it mate

http://www.hobby-lobby.com/ubec.htm

[scallybert]

It's rated at 3A - which isn't anything special ?

A switched-mod BEC is going to be more efficient, but whether that will be significant is debatable.

AIUI, a linear-mode BEC will draw the same current from your LiPo as is going to the servos, etc. (From above, that would be <3A.)

A switched mode BEC will presumably draw less than this. Possibly in the ratio of LiPo V to BEC output V. (AIUI, A switch-mode BEC is a bit like a header tank with a ball-**** & valve feeding it. The o/p V is the head of water from the tank. The LiPo V is the mains water pressure.)

So a switched-mode BEC *might* save you ~1A from your LiPo at 3S.

I'd expect it to get more interesting on an HV low current set-up. (Like a G5... ). Where the LiPo V is higher, and capacity is lower.

[cjcj1949]

Thanks, it sounds worth doing for hovering and general training as my heli sits on the ground more than its flying. I've got an original battery thats not very good and the esc gets very hot so it's all worth doing. I'm thinking of replacing the servos with the hs65s then I can run it all at 6 volts. Don't suppose the standard supertec energ 7.5g servos will last long at 6volts. How do they fit 4 hole servos into 2 hole mounts?

Chris