Wild YFZ 450

Well I was wondering if I could use a 2s lipo from my heli as a receiver pack ( Spektrum Receiver powering only a Hitec 645 Servo and a Fan )... It would seem that I would need a voltage regulator or BEC but I wasn't sure because on some websites it sells them not saying anything about the voltage levels.. Even on maxamps all it said was may require so modifications to fit in your chassis.. So im not 100% sure any help will be appreciated...

Access

You want between 5 to 6 volts for a receiver pack and the problem with LiPo is a 1s (4.2V) is too low, a 2s (8.4v) is too high so you need some kind of voltage regulator to use them.

Wild YFZ 450

I obviously know that... I was wondering if there was something different in a spektrum because I believe i have heard that there is a bec built in or something similiar in a traxxas ( haha ) so i was wondering that.. And will the extra voltagereally be that bad.. I know a full charge 2 cell is around almost 9vs so im not to sure.

dacaur

the reciver will be fine, but the servo will burn up with the voltage of a 2 cell lipo, you just need an external BEC like the castle creations 10 amp unit or something like it...

Access

I don't know of a receiver that has the BEC built in and I run spektrum in about half my stuff. The ESC might have its own internal regulator, but all the '+' and '-' pins on an ESC are common so you've got to worry about the servos too, like he said above.

Druss

The nominal voltage of a 2S pack is 7.4 volts but it will charge up to 8.4, that said some of the newer servos, like the JR 8717 can actually handle 7.4v nominal. A ubec is easy enough to find for $10-$20, this is not the same as a regulator which will cost a lot more but will do a better job of maintaining voltage levels so you avoid brown outs.

dacaur

Um, actualy, it is the same thing... A BEC is a voltage regulator....

Druss

yes and no: yes a bec regulates the voltage down from 7.4v to 6v or 5.2v but it has a hard time keeping it constant in high demand applications, a regulator does a much better job in terms of keeping the power there when it's needed. You can definitely use either though. I guess it's a matter of symantics to me but if you do a search on most hobby shops you'll find regulators start at around $30 and are much heftier, becs start at $10 and are typically smaller.

For instance, I'd consider duralite and fromeco as regulators and parkbec, castle creations and hobbywing as becs. That may be just me but there it is.