pic: Testbench with PDB backpower

[RyanN]

Originally Posted by GeeTwo

They cannot all be connected directly to each other: each circuit has its own breaker and current meter. Running power backwards through the breaker would be of no consequence (as your power supply is probably not capable of enough current for long enough to trip a 40A breaker), but running current backwards through a current meter designed for polarized current certainly could.

I recommend verifying that you check on circuit you used as the "input", both to verify that it still works, and whether its current meter still functions properly before you build a robot with that PDP and have incredible fun troubleshooting the problem.

(Besides, you wouldn't have needed any more hardware than you have in the picture - just loosen the input 6AWG feeds into the PDP a bit, slide in your smaller supply wires underneath, and tighten.)

I thought about this problem too, but then I remembered that any type of back current from the robot moving also generates this current, so hopefully the PDB is designed to handle running current backwards.

The problem of course being that microcontroller reading the voltage drop across the shunt resistor will have negative voltage at it's inputs. However, I bet it goes through an amplifier before going to the microcontroller, and those often handle negative voltage just fine.

Back on topic though. We have a similar test board using a 12V, 30A power supply that is wired into the battery input. It's been working great for testing anything from robot code, working on vision processing, or just trying new things.