Single-Lipo BEC

[Raphael]

Hi there,

I'd need a BEC working on a single lipo cell delivering continuous 1A@5V.

Is there a way to do something like this?

Thanks,
Raphael

[Chippie]

Doable, use a switching regulator, but you would need to incorporate an lvc to prevent discharging the lipo beyond the safe voltage....

[Raphael]

no, no cutoff.
Better distroy a lipo than destroy the plane.
How exactly, what do I have to do?

[Gary Warner]

Can you just run one of the new systems that accept 3.6 volts? Is this a micro sized setup?

Oh, and if you destroy the lipo then you will have a destroyed plane.

[Raphael]

thanks to both of you,
but I have really thought well about this and I do actually need a DC/DC-converter, input 3,0-4,2V, Output 5,0V @ 1A.
I need it for my competition DLG's which I have designed for lipos. Servos are 2xDymond D47 and 2xDymond D60.
I don't want slower servos directly driven on one lipo.

I am well aware about the "dangers" of over discharging the lipo, but that's really not the point here.

[Gary Warner]

thanks to both of you,
but I have really thought well about this and I do actually need a DC/DC-converter, input 3,0-4,2V, Output 5,0V @ 1A.
I need it for my competition DLG's which I have designed for lipos. Servos are 2xDymond D47 and 2xDymond D60.
I don't want slower servos directly driven on one lipo.

I am well aware about the "dangers" of over discharging the lipo, but that's really not the point here.

Ok, I do see. Hand launch is something I do too and I'm always aware of the time I have left at any given time. I run 110ma NiCad’s with 4 servos on one plane. Talk about keeping up with the battery life. I've never run it dead, but I've come very close.

I've seen a few up converters but none that come even close to 1 amp.

I'd consider moving up to 2 cells, even if the capacity was less to meet the weight and size requirements. If you do find a converter you will see that the current draw is going to be rather higher than a 2 cell setup and so moving to 2 cells at lower capacity would affect duration very much (better or worse depending on the current draw of the dc-dc converter).

[Raphael]

thanks
but I have seen that there are ESC (YGE for example) that have a BEC 5V @ 1A from 1-3cells. How do they do that?

[Zlatko]

http://www.microplanesolution.com/mps_00001c.htm

and ... not too far from you :)

[Gary Warner]

http://www.microplanesolution.com/mps_00001c.htm

and ... not too far from you :)
Do they have any more details about input voltages and current?

[Raphael]

what about that one:
http://www.chipcatalog.com/National/LM2698.htm

[Gary Warner]

what about that one:
http://www.chipcatalog.com/National/LM2698.htm
Wow, it's been a while since I've checked on these things. That Ic looks good for what you want.

[mem]

you may also want to have a look at this chip: http://www.national.com/pf/LM/LM3224.html

[Zlatko]

Do they have any more details about input voltages and current?

Hi,

I have the 300mA one, I am using it for a light weight camera/TX. Supplies 5V from 1 LiPo cell. All the other ones are for 1 LiPo. Shoot him off an email to confirm, he is fast to reply ... and will ship world wide.

Cheers

[Gary Warner]

Hi,

I have the 300mA one, I am using it for a light weight camera/TX. Supplies 5V from 1 LiPo cell. All the other ones are for 1 LiPo. Shoot him off an email to confirm, he is fast to reply ... and will ship world wide.

Cheers
Thanks.