I see no reason to use the chassis as the ground return for these DC signals
You want to hold the chassis at safe potential and give
incident EMI somewhere to go. Third prong most likely.
You do not want to make return currents of the power
distribution network travel through the case.
I like a star ground for everything.
What exactly does this mean regarding analog_GND, shielding faraday cage and metal case? This is what your picture is meant to clarify.I do plan to use the mounting holes to connect my analogue measurement pcb shielding cans to the chassis. Effectively creating a Faraday cage around measurement circuits.
Hi,
the picture isn`t very helpfull. It is of bad quality and - as far as I can see - it doesn´t show the connections and isolations you are talking about.
Picture: It seems to be a photo of a PC screen. Why not simply use a screenshot uploaded as *.PNG?
* don´t connect the "soft power switch" PCB_GND directely to the metal case. Use isolated PCB holes or isolating standoffs. It is not clear form your picture if there is a case (metal? plastic?) around the soft power switch PCB. I expect the PCB includes the switch. If this is a switch in a metal case than you may need to take care about ESD.
* use the star_GND near your PS
What exactly does this mean regarding analog_GND, shielding faraday cage and metal case? This is what your picture is meant to clarify.
BTW: a faraday cage doesn´t necessarily need a connection to the circuit.
Your metal case already acts like a big faraday cage. So why another faraday cage inside this big faraday cage? I assume there is some information missing.
Klaus
If there is sensitive analog circuit, then I´d rather concerned about "conductive noise"... --> proper filtering of the signals/wires from power supply to the analog circuitry.The second Faraday is to reduce noise from the ATX switching PSU.
Hi,
If there is sensitive analog circuit, then I´d rather concerned about "conductive noise"... --> proper filtering of the signals/wires from power supply to the analog circuitry.
Klaus
Hi,
An ATX supply is made for a lot of power. Does your analog circuit need that much power?
Don´t run into some kind of "underpower" conditions of the ATX supply with further increased voltage ripple.
The voltages of an ATX supply may carry ripple and are not that precise..
Are you sure this is a good choice?
Klaus
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?