Hi guys, my APM has recently started to reboot mid air for no apparent reason. This first happened on the 9th March when I was flying in stabilize mode and all the controls just froze (no response to…Continue
"Yes I made this decision years ago on all my APMS, its just an overall easier way to deal with this situation. And the added weight of an extra battery is moot in most aircraft if you decide to utilize more then one, which I do to keep things…"
"After extensive testing and discussion with a fellow FPVer/EE engineer, we've decided the quickest/most efficient/no-waiting-for-delivery and presumably safest modification is just to split the power rails via the jumper and run all the servos…"
"According to the data sheet of the power regulator on APM, it's about 3.3v + 90mV = 3.39v. That's how low you can get theoretically before cuts out. Of course you want to keep it between 5-6v though :)
"I did this zoom in on the trace for Vcc and the servo outputs (Log 18/3/2013). As soon as you switch to stabilize and all the servos start working together Vcc starts going up and down like crazy. Your BEC just doesn't have enough power to hold…"
"And I agree with you too.
I was pointing out that powering your setup with two different power supplies can give a false sence of redundancy. just do the math.
my personal choice is to go with one (over) powered UBEC to power everything.I don't…"
"Pieter, the problem is that if you have 5 1 Amp servos, a 5 Amp BEC, even a 10 Amp BEC, might not be enough. The problem is that servos can have a huge, instantaneous load demand. The circuitry in the BEC don't respond fast enough,…"
"Or the ultimate in simplicity and reliability:
High Voltage servos running direct on 2S. And a nice reliable linear regulator for the APM that won't experience any voltage dips.
Ah.... the crusade continues..."
"The MTBF of a APM PM regulator is 48,000,000 Hours.
With the myriad of setups that people are using the APM PM has shown is a much more reliable setup than having only one regulator. This due to less brownouts occurring. You do get manual control of…"
"Yes,you are right too.
But I must point out the period between brown out and manual control of APM is also very short, and a 2.4 ghz must re-bind with the transmitter, which takes a short moment.
This is something that everyone must decide fot…"
"An rc reciever has a very simple task of converting ppm to PWM for the servos, so can restart very quickly. The APM has a much longer boot up period, hence the dip is much more destructive.
Two seperate regulators is not an uncommon design, it has…"
"Yes, a constant voltage is critical for the stability of APM.But we've been spoiled with the capabilities of an autopilot.The ability to power your rig with 2 seperate power rails is rather uncommon in the model airplanes hobby. and we've…"