I have finished soldering a Revision D power distribution board from the jdrones kit and would now like to test it to make sure I have soldered everything correctly (I am brand new to soldering and electronics).
Here is what I have so far
My electronics experience is lacking but I have tried to test for shorts by using what I believe is the Diode test on a multimeter.
On my model of multimeter it displays the number 1 left aligned when the loop is open (no circuit), and it displays 000 or 001 if I touch the tips together.
Now what I expected is if I touch the tips on the positive and the negative areas of the power distribution board it should still display 1 to indicate that there is no circuit, however I am getting a reading of 1580.
Does this mean that I have accidentally crossed some solder from + to -? A visual inspection with a magnifying glass seems to indicate that I haven't, however the multimeter can't lie. Perhaps something in one of the ESCs is making a short?
Any help with how I test this, or an explanation of how best to test this would be highly appreciated. I have spent a long time trying to research how to do this and I consider pestering everyone about it a last resort! I just don't want to plug everything in and watch it all blow up in smoke :)
Many thanks for your time reading this
As an update I started to desolder parts to see if I could work out what was going on.
After desoldering two of the ESCs the reading changed to indicate that there was an open loop. I guess the ESCs themselves are completing the circuit but with a high resistance? Perhaps there is nothing wrong with my PDB at all.
I was under the impression that until a battery and motors are connected there shouldn't be a circuit.
I'm almost complete with the frame now but my uncertainty with this is holding me back as I don't want to blow anything up.
Certainly you were reading the ESC resistance - removing them from the PDB was the trick.
Usually there are capacitors connected between the (+) lead and (-) lead of an ESC. The charging of these caps, and any other components unknown to us, is probably what you were reading.
I would, while the ESCs are off the board use the resistance setting of the meter (low ohms) and ensure that (+) (red) only is connected to the red wires. Same for (-) (black). Because most of us operate with no fused protection, this check is always a good idea to ensure a short does not exist before applying the high current source called the battery.
Well done... so far.
Thank you Richard that certainly clears up how I should go about testing this.
Thank you for the detailed response Doug. I think I understand a bit better about how the ESCs interact with the circuit now.
Should we be adding fuses as a safety gap in case we get any accidental shorts?
I feel inspired now :)