| Suresh R 03/25/06 04:48 Read: 660 times Chennai India |
#113056 - 7805 and get 10mA and 100mA Responding to: Kai Klaas's previous message |
Neil said:
0.010 Amps * 0.020 ohms = 0.0002 volts .2 millivolts is kind of tiny A gain of like 200 watch for noise from what you have said i got that, since the measured voltage would be too less(.2mV) for low CR, this voltage(.2mV) has to be safeguarded against noise issue. If this is what you describe, what could i do to achieve it? A careful PCB design (or) handling any design technique? could you give me some knowledge of how to do that. Kai Klaas said:
And thermo-potentials! I dont have any idea about it Kai. Could you give me some more info on 'how and where it would be developed in my circuit? Kai Klass said:
Why not using a simple 1k5 resistor for the 10mA constant current and a 150R resistor for the 100mA constant current, both in combination with +15V voltage source? Even with a 2Ohm contact resistance this would result in an error of only 1.3%, if remaining uncorrected On reading the above, could i take a 7805 and get 10mA and 100mA by using two resistors at its o/p? Can you tell me how did you get that error factor. suresh. |
| 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 |