| ??? 02/02/08 16:40 Read: times |
#150226 - Common mode noise! Responding to: ???'s previous message |
Ap said:
Hi, We need to run 24VDC ,GND at 200feet to a sensor node with dedicated cable (Shielded / unshielded ) . Is there any EMC impact on the SMPS which distributes the power to these long wires? With a factory fabricated modul fullfilling the CE standards you won't have any trouble. But a self fabricated can make trouble! Use a mains filter, connect the output GND via a low inductive cap to the input GND (eventually protection earth) and feed the cable (both 24V and GND!) through a soft ferrite toroid choke. Of course, the output voltage must also be low pass filtered relative to GND, to remove the ripple. Usually a shielding of 24V line isn't needed. Depends a bit on the actual 24V supply line filtering in your sensor. Normally a twisting is enough. At least, avoid the introduce of loop areas. Kai |
| Topic | Author | Date |
| Powersupply issue | 01/01/70 00:00 | |
| Common mode noise! | 01/01/70 00:00 | |
| I run 24V for distances and ... | 01/01/70 00:00 | |
| using a choke in the ground line ... | 01/01/70 00:00 | |
| using a choke in the ground | 01/01/70 00:00 | |
| RS232 is 'pwer ground' referenced | 01/01/70 00:00 | |
| use 485 or opto --nop its not the case infact | 01/01/70 00:00 | |
| OK, bending it in neon | 01/01/70 00:00 | |
| OK, bending it in neon --- Absolutely | 01/01/70 00:00 | |
| the fallacy about a wire | 01/01/70 00:00 | |
| the fallacy about a wire ---What about Power | 01/01/70 00:00 | |
| so what? | 01/01/70 00:00 | |
so what? | 01/01/70 00:00 | |
| Differential mode chokes? | 01/01/70 00:00 | |
| Figure 3c ... | 01/01/70 00:00 | |
| Figure 3c ... | 01/01/70 00:00 | |
| Only an illustration... | 01/01/70 00:00 | |
| Only an illustration... | 01/01/70 00:00 |