I am working on a hexacopter build and looking for some advice on PDBs and other boards that might be a combination distribution/management system. The setup should be drawing about 40A at hover and around 110A at max throttle. Could someone here make any comments/recommendations on the following options regarding principally reliability? Unfortunately I’d have to double up the PDB360 for the six rotors, but they seem to be high quality. Honestly I’m struggling to find much for use cases for any of these seemingly best options.
I know the APD one has been independently bench tested to ridiculous current levels and survived without even getting warm. It should be very reliable.
The SmartAP PDB may possibly have the current and voltage sense outputs set up for 5volts - they don’t specifically say in the doco. Ardupilot compatible boards typically expect 3.3v
Nice thank you for that information. I hadn’t looked at the voltage issue with the SmartAP PDB but I think you’re right that it’s not set up for 3.3V. Thanks!
These APD PDB360 boards are 50 grams each! That’s heavy needing two for the hex build. Anyway, yeah actually I am looking at this now and the Ardupilot boards I’m using (mRobotics stuff) are actually 5V I believe. Thanks again for the help!
The APD boards dont have a current sensor unfortunately, but you could put two ESCs on the second set of battery input tabs.
The APD ESCs do measure current reasonably accurately (from what I’ve tested so far) if you have enough Flight Controller motor outputs that support DSHOT, and just use parameter BATT_MONITOR,9
Well I just broke down and bought a Vulcan UAV PDB from a local distributor. I spoke to the good folk at mRo and the ACSP4 isn’t up to the job–the Holybro and SmartAP boards not sure. If APD just had a single board hexacopter solution, I’d certainly try it. Thanks again for your help @xfacta. I suppose what I’d call a Power Management and Distribution Board would really be the way to go. Any comments on the SmartAP and Holybro boards would still be greatly appreciated.
Thank you I appreciate the response. Yeah the Mauch PDB looks great but it is a bit outside my weight/size and frankly budget requirements for this build. Cheers.
I’m using one of the APD 500 ones, and like Shawn says it can take some insane current. That definitely won’t be a concern.
However, be aware that it uses switching power supplies for the 5V and 12V outputs. The voltage output is susceptible to sag under load, and is pretty noisy. Screenshot of my 5V line attached.
Not certain what your plans are for powering things, but the 5V line from this board is not suitable to be directly connected as input to the Pixhawk for sure or in my case a Pi. Other than that, the APD one has been great!
Thank you for the reply. Wow that does look fairly noisy on first glance. I wonder if others are seeing the same thing? I hadn’t thought that line was intended for powering a flight controller or SBC but hadn’t really looked at it yet. The plan for this build was to run power for the Pixhawk out of the power module upstream of the PDB, but I’m finding the standard power modules are not quite rated for the potential burst currents, so planning on using some of the Mauch power stuff. Learning much as I go.
Frankly, I like the idea of just using mechanical connectors and terminal blocks for power like Blue Robotics is doing in their really neat looking ROVs. No splicing, fully visible connections, easily repairable. I hear the arguments for why not to do this relating to vibration etc. but do wonder if that’s the right way to be thinking. For example, I don’t think soldered connections are standard in aerospace electronics. However; I will continue to solder away!
Yeah, that sounds like about the same setup I’ve got. Here’s a wiring diagram for what I’ve got set up at this point (for the power & drivetrain, at least). I have a Mauch power monitor as the first thing the battery power encounters, then to the PDB and the rest of the system, and that’s worked quite well.
(Another note: the Pixhawk Cube, at least, does not want 5.00 volts, it wants 5.35 volts. Not much, but out of spec for most power bricks. The Mauch system was designed to accommodate this. Learned that the hard way…)
Oh nice wiring diagram! Okay glad to hear we are thinking along the same lines here. Thanks for your help with this. Interesting to hear about the Cube voltage requirements, they are the same as for the mRo X2.1 I’m using right now.
