| Kai Klaas 03/30/06 05:35 Modified: 03/30/06 05:57 Read: 554 times Germany |
#113403 - This would be the Lock-in scheme Responding to: Oliver Sedlacek's previous message |
Oliver said:
I would have thought that a simple demodulator using analogue switches would be a worthwhile addition to this circuit. Yes, of course, that would be the lock-in scheme, with superb noise suppression characteristics. Unfortunately, offset voltage of OPamps would again come into play and so, you would need such a synchronous demodulator at each of the four outputs. Then, you would add an inverter and choose the true or inverted signal by the help of CD4066 for instance, and would do this with the same rhythm as the BC337 is toggling. Kai |
| Topic | Author | Date |
| Measuring CR of Reed Switches. | Suresh R | 03/22/06 05:24 |
| Contact resistance? | Oliver Sedlacek | 03/22/06 06:41 |
| Correction : Sorry its 10mV to 2500mV | Suresh R | 03/22/06 08:17 |
| Voltage or current, pick one | Oliver Sedlacek | 03/23/06 02:12 |
| I can choose Test current as 10mA | Suresh R | 03/23/06 03:09 |
| typical constact resistance ? | Steve M. Taylor | 03/23/06 05:38 |
| yes, but | Erik Malund | 03/23/06 06:52 |
| No CR when closed? | Suresh R | 03/23/06 09:46 |
| If this was possible, you would not need | Erik Malund | 03/23/06 10:37 |
| current source with series resistor at | Suresh R | 03/23/06 11:22 |
| Yes | Erik Malund | 03/23/06 11:48 |
| constant current source | Terry Lingle | 03/23/06 13:18 |
| V=IR | Neil Kurzman | 03/23/06 15:10 |
| Specs & Description | Suresh R | 03/24/06 04:47 |
| resistor ? | Steve M. Taylor | 03/24/06 01:45 |
| Current source circuit for CR measuremen | Suresh R | 03/24/06 10:06 |
| Why not using... | Kai Klaas | 03/24/06 10:35 |
| Kind of | Neil Kurzman | 03/24/06 18:06 |
| And... | Kai Klaas | 03/24/06 20:38 |
| 7805 and get 10mA and 100mA | Suresh R | 03/25/06 04:48 |
| reply - thermo-potentials | Suresh R | 03/26/06 03:39 |
| since you work for the manufacturer | Erik Malund | 03/26/06 10:50 |
| Chopper | Kai Klaas | 03/26/06 20:04 |
| Chopper schematic | Kai Klaas | 03/27/06 05:58 |
| Thanks very much Kai. | Suresh R | 03/27/06 10:35 |
| Reply : Chopper Schematic | Suresh R | 03/28/06 11:36 |
Answers  | Kai Klaas | 03/28/06 19:58 |
| what about a chopper stabilized op-amp? | Erik Malund | 03/29/06 06:14 |
| Yur. | Steve M. Taylor | 03/29/06 07:22 |
| Yes, but... | Kai Klaas | 03/29/06 08:36 |
| AC components , VCR, DCR | Suresh R | 03/29/06 11:59 |
| Answers | Kai Klaas | 03/29/06 20:18 |
| Demodulation? | Oliver Sedlacek | 03/30/06 01:06 |
| This would be the Lock-in scheme | Kai Klaas | 03/30/06 05:35 |
| Average Value, VCR & DCR Calculation | Suresh R | 03/30/06 05:30 |
| Quite simple | Kai Klaas | 03/30/06 05:45 |
| Analysis for Usig o/p | Suresh R | 03/30/06 11:56 |
| Answers | Kai Klaas | 03/30/06 20:33 |
| I thank you very much Kai | Suresh R | 03/31/06 04:48 |
| Test Condition: 10mA, 50mV | Suresh R | 04/19/06 10:06 |
Switching condition | Kai Klaas | 04/19/06 10:14 |
| Remember Ohm's law? | Richard Erlacher | 03/23/06 12:50 |