Backup system for BEC
So after much reading and research into the whole "backup" BEC saga. I think I've found a solution!
My first idea was just to run a 5.5v backup lipo in parallel with the 5v UBEC output.
This idea has been vitoed by most. Too many unknowns apparently.
The other was to parallel all the BECs up, but this would cause harmonics due to all the square wave interaction.
So I figured we cant mix power supplies. Other than using a microproccessor controlled mosfet to switch
power supplies when and if the bec dies.
We use a relay :) Bear with me.
The main power supply powers the relay. With the relay closed (NO) power is routed via the bec to the apm.
If the bec fails, the power to the relay fails and is switched to the auxillary power supply (battery or another bec)
This completely seperates the two power sources.
Will the relay be able to switch fast enough to the auxillary power source without the APM losing power?
If not, im sure a power capacitor will keep the APM alive long enough for the bi-pass surgery to take effect?
Above is a recording of the ciruit just in case my explaining skills are dodgy :)
-
Comment by Gustav Kuhn on January 12, 2012 at 11:40pm -
Ah, but you also draw nice pictures:-)
Yes, that is what is in my pictures, just remember that you would want to fit a 6800uF10V capacitor either on the receiver, or the APM.
I use a replacement servo pigtail soldered.......
Easier like this :-)
-
Comment by Gareth Rens on January 13, 2012 at 12:14am -
Gustav: I draw the digrams on circuit wizard, great for quickly drawing diagrams, sh*t for everything else.
Its quicker and easier than isis or eagle.
The above cap, is it for smoothing or something else?
-
Comment by Gustav Kuhn on January 13, 2012 at 12:42am
-
No, not smoothing as such.
It is more like a short term backup battery:-)
It lowers the perceived impedance of the BEC's.
But it will smooth out small spikes coming from the BEC's too.
Cheap, easy extra insurance.
What a lot of people don't know, is that you should use electrolytics fairly near their rated voltage, to get the best performance out of them.
I would have liked to use 6V units, couldn't source any locally.
-
Comment by Gareth Rens on January 13, 2012 at 1:19am
-
10-4!
Agree with you on the cap rated voltage!
6.3v 6800uF: http://www.mantech.co.za/ProductInfo.aspx?Item=14M3873
:)
-
Comment by Gustav Kuhn on January 13, 2012 at 1:31am
-
Hah, ANOTHER Sefrican on this list!
Thanks for the heads-up, we have a branch in Cape Town.......
-
Comment by Gareth Rens on January 13, 2012 at 1:37am
-
lol, i thought you knew i was "African" :)
-
Comment by Gustav Kuhn on January 13, 2012 at 1:58am
-
Mmm, maybe it is time to organize an away weekend (long), for all of us "African Drones", compare notes, fly, crash, show off, and generally have a good time :-)
Obviously I would like that at my home field!
-
Comment by Gustav Kuhn on January 13, 2012 at 2:03am
-
OR, make that a subdivision of say, the Robertson Fly-in next year, full size runway, camping facilities, many B+B's, out of controlled airspace, farmland, I for sure will be there.
-
Comment by Gareth Rens on January 13, 2012 at 2:20am
-
That sounds like a plan :)
-
Comment by Johann Van Niekerk on January 13, 2012 at 4:22am -
Question : why do you want a backup system on your APM ? if you doing this on a copter for battery power for motors long before you kill a 850Mah battery on a APM running APM from same battery then get other battery
Social Networking
Top Content
Contests
Season Two of the Trust Time Trial (T3) Contest has now begun. The fourth round is an accuracy round for multicopters, which requires contestants to fly a cube. The deadline is April 14th.A list of all T3 contests is here.
Groups
-
ArduCopter User Group
1289 members
-
ArduCopter Evolution Team
140 members
-
Learning to program the …
313 members
-
ArduIMU Gimbal Controller
44 members
-
Arducopter Tech Support
5 members
Advertisement
© 2013 Created by Chris Anderson.
Powered by
You need to be a member of DIY Drones to add comments!
Join DIY Drones