Can I give supply and signal to a controller from different sources?

[ibrar]

Hello All

i have a question

if i give supply to a controller from one source and give it a signal from another supply source will it detect the signal or not

thanks

 

[master_picengineer]

Question

Yes if the two grounds are connected together.

 

[chillimillii]

Re: Question

yes it will detect the signal

 

[A.Anand Srinivasan]

Re: Question

it will detect but if your grounds of the two supplies are not the same then there would be a shift in the actual input....

 

[sivakumar_tumma]

Re: Question

If both grounds are conncetd then it will work

 

[A.Anand Srinivasan]

Re: Question

It is not mandatory that the two grounds be connected together... there a many isolation devices and circuit configurations are available to avoid this problem of different grounds...

 

[sarafcina]

Re: Question

It is not mandatory that the two grounds be connected together... there a many isolation devices and circuit configurations are available to avoid this problem of different grounds...

well, if he wants to sense that signal/supply then the has to be a potential difference. And, then it comes... what he is sensing...

 

[A.Anand Srinivasan]

Re: Question

well, if he wants to sense that signal/supply then the has to be a potential difference. And, then it comes... what he is sensing...

i dont know whether you are supporting my point or not... it aint clear....

but what i mean is that the signals can be easily feed using optocouplers and transformers without necessarily having to short the two grounds....[/quote]

 

[sarafcina]

Re: Question

well, if he wants to sense that signal/supply then the has to be a potential difference. And, then it comes... what he is sensing...

i dont know whether you are supporting my point or not... it aint clear....

but what i mean is that the signals can be easily feed using optocouplers and transformers without necessarily having to short the two grounds....

supporting of course
i was just saying basic principle (potential difference thing...) and then saying that the main issue is to understand what he is sensing (inputs, outputs, levels needed, price estimate, sensitivity, precision...). Sorry for not being clear...lack of time and a bit of lazynes..