View Full Version : Running the stock ESC/BEC & external BEC togehter
gww528
05-06-2008, 09:18 AM
Is is possible to run an external BEC and stock ESC/BEC to together? This way you will have a backup in case one fails.
Thank you
jackp1
05-06-2008, 09:31 AM
i dont think it works that way, i use the align esc with an external HHercules 5/6v bec. you have to cut the bec wire on the esc,normally the red middle one then the esc just powers the motor. i no what your thinking, maybe it would be a back up if one failed but it wont work with two bec's chances are you will fry them both IMO hope this helps..
aballen
05-06-2008, 10:30 AM
yeah its one or the other
Most becs are pretty reliable, in fact a lot of people use the internal bec. personally I like a separate bec be aide it allows the esc to run cooler
Aberdeen
05-06-2008, 01:27 PM
Depending how a BEC fails, the failed BEC can take out the working one.
Is is possible to run an external BEC and stock ESC/BEC to together? This way you will have a backup in case one fails.
Thank you
You can do that by using diodes in series with each of the BEC before tie them to the power bus. Remember that you must have a big enough diode to supply current to the servos. Please see picture.
gww528
05-06-2008, 02:03 PM
Thank you for the diagram
Aberdeen
05-06-2008, 02:25 PM
I thought about that allready, but you will get a voltage drop about 1 volt depending on loading.
Routybouty
05-06-2008, 04:05 PM
If it's capable, set the external to ~1 volt higher than what you want. If you want 6v set to 7v (leaving the internal at 6v (5v output with diode), then the internal will remain unloaded and the external will do all the work. This way the internal won't do anything (remaining cooler) unless the external fails. Only do this while using the diodes though.
... set the external to ~1 volt higher than what you want ...
Yeah, I forgot to mention that. Diode drops about ~0.7V, so you need to compensate that voltage to get your desired output.
For example: set BEC output at 6V to get 5.3V output voltage after the diode.
HeliBurns
05-06-2008, 11:18 PM
Spec the diode, a schottky diode will have about 0.5V drop.
Make sure to use a diode that exceeds the peak BEC output current by ~25 to 50%