I'm putting together a UAV using an APM 2.5, the APM power module, and the 3DR 915 Mhz radio system. When I first put it together, the RC electronics were not functioning properly. When I started to look into what was wrong, I hooked everything up through me E-Flight power meter to see what kind of current I was drawing to see if I could use a power supply instead of running down my batteries. The power meter showed that the plane was drawing about 50 amps, without the motor plugged in. I was able to figure out why the flight controls weren't working, but I still don't know why everything is pulling so much current. If I unplug the telemetry air module, the current drops down to about .1 amps, right where I thought it should be. Does anyone have any ideas on why the radio would be drawing so much power? I don't want to hook this up to my batteries like this, they are not rated to handle that much draw. I'm currently using a 12 volt sealed lead acid battery to power everything on the bench.
Thanks for any help you can give.
Josh
Replies
@Josh,
A current draw of ~50amps would have smoked the telemetry air module if it indeed was drawing that much current.
Are you sure that the E-Flight power meter is reading the right current?
Did your battery get hot with that kind of current draw?
Since you are powering the APM with the PM, have you removed the J1 jumper?
How are you powering your servos on the APM output?
I think that you should perform a thorough inspection of all your interconnecting wiring and verify that it is correct and there are no shorts to ground anywhere in the interconnections.
Regards,
TCIII