| Erik Malund 03/23/06 10:37 Read: 591 times Mt Airy, Nc USA |
#112890 - If this was possible, you would not need Responding to: Suresh R's previous message |
Erik Malund said: for an IDEAL switch
and zero voltage and zero resistance when closed. there ain't no such thing as ideal. But i was asked to measure the CR of the Reed switch by passing 10mA current at 20mV through the contacts. If this was possible, you would not need to measure the resistance, just calculate it (2 ohms). You can't specify a voltage, the voltage is the drop across the switch AT a current. If you apply a voltage and the voltage is too high (20 mV may very well be too high) the switch is DEAD (melted) The ONLY way to measure switch resistance is to pass a known current and measure the voltage drop. Erik |
| 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 |