Olimex Support Forum

Microcontrollers => PIC => Topic started by: toozie21 on January 05, 2015, 10:24:20 PM

Title: Recommended way to tie external ground to PIC-MAXI-WEB
Post by: toozie21 on January 05, 2015, 10:24:20 PM
Something I wasn't thinking about when I originally purchased the PIC-MAXI-WEB was that due to the rectifier on the input connector, the ground that connects to the power pins does not equal the ground that runs around the board (which means it doesn't equal the ground on other devices connecting to it).  What is the recommended way to make sure that the board ground is equal to the ground coming in from the power supply (I am running the board off of +12VDC)?

I see two potential options:
1 - tie the board ground to the ground coming in.  I don't think this is going to work though since the board ground is the same as the ground coming in, minus going through the inductor.

and

2 - not connect the ground to the input power connector and instead tie it to the ground post that was supplied.

Any thoughts?
Title: Re: Recommended way to tie external ground to PIC-MAXI-WEB
Post by: MBR on January 13, 2015, 10:08:37 PM
I recommend the second option - connect the input power connector only by the positive wire (to PWR-1), let the other one (PWR-2) unconnected and connect negative wire directly to the ground, effectively bypassing the input Graetz bridge (only one diode will be active).
Title: Re: Recommended way to tie external ground to PIC-MAXI-WEB
Post by: toozie21 on January 15, 2015, 02:31:23 PM
Thank you, that is indeed the way I went (I forgot to comment on here about my end decision).  Seems to be working well!