using an an isolator for stuff using the same power supply.

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Gibson486

Joined Jul 20, 2012
327
Would it be over kill to use a receiving isolator (such as for RS232...ADM3251) for devices that run on the same power supply? For example, if I have a computer, everything would be powered off the same supply. However, there would be different boards with in the computer and they need to talk to each other. One would simply think that you would just hook all the grounds together, however, what if there are multiple ground points with in each board. For RS232, you have the ground in the cable that connects to the motherboard, but you also have the ground on the same board that connects to the power supply. Would this potentially create a ground loop since some boards would have multiple paths to ground?

Thanks!
 

alfacliff

Joined Dec 13, 2013
2,458
the grounds in pc's are all common. the only time the grounds may be not common with the motherboard is for boards that are internaly islolated input and output boards, which have their own isolation built in. like rs232 boards, which onoly isolate ground for noise problems.
 

alfacliff

Joined Dec 13, 2013
2,458
and rs422 and o0ther internal serial communications does not refference ground anyway, it is two wire with each 180 degrees out of phase. differential pair serial is normally used to reduce noise and cross talk. anything coming into he board from outside should be isolated to reduce noise and possablility of static surges getting into the computer.
 
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