Timeline for Using Chassis as a conductor for DC Power Supply Return
Current License: CC BY-SA 4.0
7 events
| when toggle format | what | by | license | comment | |
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| Jul 24, 2018 at 22:37 | comment | added | user1908704 | The power supply is DC. Coupled interference is at kHz (from SMPSUs) or MHz (radio transmissions/leakage). Even if it's coupled into the power input, the voltage regulator only has so much capability to block RF. However it's more of a problem when interference is coupled into data lines rather than power lines - for example other devices connected to the Pi. It depends whether the ground reference for those is the Pi or the PSU end - if they're referenced from the PSU end then it'll be superimposed on the Pi data signals. | |
| Jul 24, 2018 at 22:28 | history | edited | user1908704 | CC BY-SA 4.0 |
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| Jul 24, 2018 at 22:28 | comment | added | Maple | This is the first time I hear about "Magnetically coupled interference". Even in your description any hypothetical current induced in 1 loop of power circuit will go into power lines where it will have no effect whatsoever. Unless you are talking about NEMP, in which case it does not matter anymore. | |
| Jul 24, 2018 at 22:01 | comment | added | user1908704 | The loop is: 5V of PSU -> cable -> Pi -> chassis connection -> chassis -> chassis connection -> GND of PSU. That's why it's large (and potentially high resistance if one of those connections isn't good). | |
| Jul 24, 2018 at 22:00 | history | edited | user1908704 | CC BY-SA 4.0 |
added 104 characters in body
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| Jul 24, 2018 at 21:59 | comment | added | Transistor | Where would the loop form if there was no 0 V connection between the devices and only a chassis connection as explained in the question? | |
| Jul 24, 2018 at 21:54 | history | answered | user1908704 | CC BY-SA 4.0 |