| ??? 01/17/05 01:00 Modified: 01/17/05 01:03 Read: times |
#85058 - Thicker cable Responding to: ???'s previous message |
Kalpak said:
If hum or noise or RFI is what you wish to eliminate, better use filters, more controlled and definitely more predictable AC behaviour. Nice idea. But what, if signal bandwidth is 1kHz, how to filter out 50Hz hum then? If the analog front end does not have high input resistamce then the current flow into it will cause a line voltage drop in the field wiring and transducer output amplifier. The line voltage drop in the transducer amplifier is often cancelled by having every source impedance (protection purpose, etc.) included in the feedback path of transducer amplifier. Any such voltage drop will be eliminated by this technique, as I wrote earlier. Against line voltage drop in field wiring using thicker cable is a better idea, than to increase load impedance. Especially if the cable is very long. ...in poorly designed mains operated transducer the capacitive coupling/leaky insulation can cause enough problems if not smoke/failure when connected to the control system. Because of this I mentioned to use only Safety Class I or II systems. This standard forbidds poorly designed mains supplies! Kai |
| Topic | Author | Date |
| Source Impedance | 01/01/70 00:00 | |
| Re | 01/01/70 00:00 | |
| Impedance measurement | 01/01/70 00:00 | |
| Being more concrete | 01/01/70 00:00 | |
| What about my Rogowski Coils. | 01/01/70 00:00 | |
| Already answered in detail! | 01/01/70 00:00 | |
| Re: ' Detailed Answer' | 01/01/70 00:00 | |
| Bridge | 01/01/70 00:00 | |
| What Bridge, | 01/01/70 00:00 | |
| bridge | 01/01/70 00:00 | |
| and ... | 01/01/70 00:00 | |
| Using an OPamp | 01/01/70 00:00 | |
| Using OpAmp | 01/01/70 00:00 | |
| Some disadvantages | 01/01/70 00:00 | |
| Correct formula | 01/01/70 00:00 | |
| Thanks Kai, | 01/01/70 00:00 | |
| LCR meters quite common | 01/01/70 00:00 | |
Re: LCR Meter. | 01/01/70 00:00 | |
| Resonant coupling... | 01/01/70 00:00 | |
| Sorry! | 01/01/70 00:00 | |
| Go with the rule of Thumb | 01/01/70 00:00 | |
| No more than about 10kOhm | 01/01/70 00:00 | |
| Line drops | 01/01/70 00:00 | |
| Thicker cable | 01/01/70 00:00 | |
| Freq domain analysis | 01/01/70 00:00 | |
| re: Source Impedance and driver types | 01/01/70 00:00 | |
| universal solution | 01/01/70 00:00 | |
| Thanks .... | 01/01/70 00:00 |