Good morning,
I think there is an error with the BlackBoard schematic REVx04 dated:6/29/2020
It looks like two of the wires to barrel plug connector are reversed.
Here is a crop of that schematic with the two wires, A and B identified.
Thanks for taking a look.
-Monta
Eh…the schematic appears correct.
Most boards use a center-positive connector…is the connector you are using also?
No, the schematic is wrong. The center terminal ( the one connecting to D1) is correctly the positive one.
The sleeve contact (the one labeled B) should be tied to ground
The switch contact (the one labeled A) is connected to ground when the plug is not inserted, and open when the plug is inserted. This should go to the gate of Q1.
/mike
As Mike said, the center positive is correct.
If it was actually wired as shown there would be a conflict between USBVCC and VIN when an external power supply is connected because the line to the gate of Q1 will be connected to GND in both cases, instead of being pulled high by R4 when a plug is connected. I picked the Blackboard and schematic to use in a class, and that’s when I noticed the “typo”.
Thanks for reviewing it.
-Monta
TS-Russell:
Eh…the schematic appears correct.Most boards use a center-positive connector…is the connector you are using also?
Center positive is correct.
It is the other two wires that are reversed. See comments above.
Thanks,
-Monta
My apologies; thanks for helping us out! I’ll forward this to the engineering team
