| ??? 01/16/05 14:55 Read: times |
#85048 - What about my Rogowski Coils. Responding to: ???'s previous message |
Dear Kai,
Thanks a lot for your source impedence calculation formula. Raghu, I apologise for bumping into your thread with my problem. I hope you dont mind. I am using rogowski coils made up of 31 guage copper wire wired onto 7mm dia PVC pipe former. It is having 4000 turns wound as 4 layers. It shows a DC resistance of 25.5Ohms when measured using a DVM. I am using these coils for measuring welding currents of the order of several kilo Amperes. These coils give me a voltage signal directly proportional to di/dt. I am giving this signal to a full wave precision rectifier built around OP07 its the same circuit you gave me earlier. The output of this rectifier goes to PCF8591 ADC through a 4k7 in series with output and a 10n in between the signal and ground forming a low pass filter. I never knew I need to consider the source impedence of the coil or not I will be very greatful if you pleae give me some links from where I can learn more about the impedence matching for such measurements. Thanks a lot. Regards, Prahlad Purohit |
| 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 |