BEC voltage question

[skiprch]

Hi all,
I have a BEC in my sub and it was being fed by 6 volts. I am now needing to go to 12 volts because of a motor change. Will the BEC handle the 12 volts? It's been so long I forgot the specs. I got the BEC from SubTech about 4 years ago.
Thanks, Walt

[JWLaRue]

Walt,

The SubTech BEC will work

Walt,

The SubTech BEC will work with either a 6-volt or a 12-volt input. I mostly use 12-volt batteries in my subs and have had no problems to date. Just make sure that you use the heat sink!

-Jeff

[pirate]

Walt,
I highly recommend NOT using

Walt,
I highly recommend NOT using the SubTech BEC on 12V. I've had three of them burn up on me, and the last one was Thursday night before the SubRegatta. It then sent 12V through my receiver, speed controller, APC and servos, and burned out the APC, speed controller and two servos.

I switched to the Mtronik Viper-15 speed controller with a built-in BEC and eliminated the remote BEC. The speed controller has a built in short protection, so hopefully it won't have the same problem. Any of the Mtronik Viper speed controllers have the built-in BEC. It performed terrifically on Sunday once I got it installed. Less to install too.

That's my experience. After three sets of SubTech BE/VRs, speed controllers and APCs, I've finally learned my lesson now that there's a good alternative.

Pete

[JWLaRue]

Pete,

That's good feedback. I wonder

Pete,

That's good feedback. I wonder what might be different between my setups and yours?

-Jeff

[Guest]

I've never had one of

I've never had one of Subtech's BEC's in my hot sticky hands, however I've seen pictures of them, and they look to be a straightforward design based around a linear regulator, possibly a 7805 or a low dropout variant, which should drop the voltage down to 5 volts for the radio gubbins.

If you increase the voltage, then you increase the power the regulator has to 'brickwall' which it sticks straight to heat.

Generally these regulators can supply about 1 amp of current before they need to be bolted onto a decent heatsink.

Perhaps some folk are pushing the regulator too far. However 12 volt operation shouldn't be a problem, in fact linear BEC's tend to work a bit better with a higher battery voltage, especially if they aren't built around a low dropout design.

Personally, I'm a convert to switchmode BEC's. These offer a much more flexible approach, are small and cheap now, and much more efficient.

See here for some very neat designs includign a pin for pin replacement for a 78** style linear regulator, which would probably be ideal for retrofitting those cooked Subtech BEC's if you're handy with a soldering iron -

http://www.dimensionengineering.com/

Andy

[tsenecal]

Walt,

this is the BEC i

Walt,

this is the BEC i use when the ones in my ESC are not up to the load...

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

[bob the builder]

I've run the SubTech BEC/VR

I've run the SubTech BEC/VR for years and I've never had an issue...

[Guest]

Okay, silly question Bob. Why

Okay, silly question Bob. Why are you using a subtech BEC when the ESC's i sent you have BEC built in?

Andy

[skip asay]

Jeff Larue said -
"That's good

Jeff Larue said -
"That's good feedback. I wonder what might be different between my setups and yours? "

That's a very good question. Over the 13 years I had SubTech I sold literally THOUSANDS of BE/VRs and, while I won't say that none of them were defective, the ratio of good to bad was so small as to be not worth reporting. But Pete, THREE bad ones? And I've never seen one pass battery voltage straight through when it goes belly up. They just stop working altogether.

Can you supply any more info?

Skip Asay

[pirate]

Skip,
e-mail me your address and

Skip,
e-mail me your address and I'll send you the parts and a diagram of how I have things hooked up.

Pete