Connecting AC and DC grounds on breadboard

[bobdxcool]

Hi Guys

i believe we can connect ac and dc grounds together on a breadboard irrespective of the voltages. this is because there is no current in the ground pins. As long as we dont connect neutral of power supply (120V), i think we are fine.

please correct me if I am wrong.

i am connecting micro controller, motors , driversand power supply (120v ac) grounds together on bread board.

 

[barry]

Whoa!!!!! This is about as fundamental as it gets.

There is no current in the ground? BIG MISTAKE!!!! If current flows in the power supply line, where do you think it returns?

While it's true that the ground potential for both AC and DC MAY be the same, there are most DEFINITELY CURRENTS FLOWING IN THE GROUND. You need to be careful that you take into account where the currents are exactly flowing, particularly on a crummy breadboard. If you've got a 5 amp motor, and your ground impedance is, say, a tenth of an ohm, this is going to generate a 0.5 volt differential in the "ground" potential. This could be disastrous to any low-level circuitry; and could even impact digital signals.