| ??? 02/09/05 18:11 Read: times |
#87023 - Did I Miss Something -Kai. Responding to: ???'s previous message |
Dear Kai,
Today I tested the circuit that I had built using the schematic you posted. The circuit appears to be working absolutely fine except one thing. kai said:
To take into consideration manufacturing tolerances of Rogowski coils, 'Ra' was implemented. If you set Ra = 2.5kOhm nominally, then you can choose Ra = 0...5kOhm to adjust the output signal with a span of +-20%. You can put the once found 'Ra' directly near Rogowski coil, perhaps in the plug. I had connected 'Ra' exactly the same manner you showed in schematic but it seems to be not working to adjust the output signal of rogowski coil. I tried changing the value of 'Ra' but there is no change seen in output of integrator. Please let me know if I am missing something. Waiting desperately for your kind reply. One more small doubt.. kai said:
How to adjust the offset voltaqe? Connect the input of integrator directly to ground by the help of a very short wire. Any existing offset voltage of OPamp will be amplified by the factor (4M7 + 10k) / 10k = 471 then. Now adjust the output of TL051 to exactly 0.0mV. Remove the ground connection. That's it. I think you are refering to the 100k trim pot in your schematic when you said adjust the output of TL051 to exacly 0.0mV am I right? Thanks & Regadrs, Prahlad Purohit |
| Topic | Author | Date |
| My Rogowski Coils | 01/01/70 00:00 | |
| If it ain't broke | 01/01/70 00:00 | |
| Lack of confidence. | 01/01/70 00:00 | |
| Art of electronics | 01/01/70 00:00 | |
| No I haven't. | 01/01/70 00:00 | |
| OP AMP basic definitions | 01/01/70 00:00 | |
| Kai- Please Check your mailbox. | 01/01/70 00:00 | |
| Three things that scare me. | 01/01/70 00:00 | |
| More concrete schematic | 01/01/70 00:00 | |
| Re: Concrete Schematic. | 01/01/70 00:00 | |
| Rogowski coil | 01/01/70 00:00 | |
| Did I Miss Something -Kai. | 01/01/70 00:00 | |
| You should see a change! | 01/01/70 00:00 | |
| Yes I could see the change Thanks. | 01/01/70 00:00 | |
| Alu foil, asbestos shield | 01/01/70 00:00 | |
| Asbestos | 01/01/70 00:00 | |
There's no 'corner frequency' | 01/01/70 00:00 | |
| Integrating Capacitor. -Kai | 01/01/70 00:00 | |
| MKP, select for low offset | 01/01/70 00:00 | |
| How about these. | 01/01/70 00:00 | |
| Are ok | 01/01/70 00:00 |