making a circuit grounded

[shaiqbashir]

hi guys!

well im making a circuit involving the PC serial port. One pin i need to ground. Now i want to ask you that how should i do that!

should i just connect it to the negative terminal of my battery?
or should i make this ground by some special way? if this is i have to do then how to do it?

thanks in advance!

 

[riteshjain_82]

yes just connect itto the negative of the circuit but remember the negative of the circuit must be connected with negative of the computer

 

[prateeksikka]

the only thing is that the PC side and the circuit side should have a common ground...be it directly shorted or through an optocoupler.
just see the amount of power on both sides ,if it differs by a large amount then better use an optocoupler otherwise short the grounds directly.

 

[MP1]

The two plugs coming from your computer power supply that connect to the motherboard have a 2 black wires on each plug which are next to each other when plugged onto the motherboard. These are common and will give you the best connection to power supply common if this is what you are looking for.

MP

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