Trying to power my APM 2.5 from the output side, I've installed j1 jumper but only have 1.4v at the fuse as shown to measure here: http://code.google.com/p/ardupilot-mega/wiki/APM25board. I can power it via the output bus but would prefer not to.
Any suggestions.
Thanks, Ken
Replies
Yes, the diode can be replaced, or bypassed.
In your case I would just lift it off and bypass it with a solder bridge or very small wire jumper soldered in.
The purpose of the diode, I think, is to prevent reverse voltage connection when powering via the Output header. As you have APM2.5, you would still have the fuse for some protection even if the diode is bypassed/removed.
If you are comfortable with an electrical schematic, there is a simplied power schematic for your board HERE.
The next question is: Which component is D1?
D1 and F2 are inside the shocking pink box above. D1 is parallel to JP1 just inside the Output header rows.
Good Luck!
-=Doug
When J1 is in, you are powering the APM from the output bus. Normally a BEC internal to one of the ESC's. If the output bus is 5-Volts, then the diode in series with J1 drops the voltage by .6-volts.