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???
03/30/06 12:30
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 		 #113402 - Average Value, VCR & DCR Calculation
Responding to: ???'s previous message
Kai said:

Take the average of several succeeding readings to cancel noise and hum interference.


Suresh said:
So i think this would also give the VCR (Variable Contact Resistance).
To do this, can the successive readings be taken by 1)running a for loop in the software part or, 2) should the coil that drives the switch be subjected to some frequency for a short period?


Kai said:

The contact of reed relay is closed during the whole measurement. Only the BC337 toggles


Then could you tell me how the average of succeding readings would be taken?

Kai,
I would like to know what is an VCR (Variable Contact Resistance) and DCR(Dynamic Contact Resistance).

What i know about it is,
VCR = The average of the value of CR measured before and after 10 cycles of switching.
DCR = The CR measured when the reed switch operates, with the operate frequency being 50Hz.

If what i have stated could be a complete definition (of VCR and DCR), then i would like to know whether it could be calculated using our circuit or not?

Thanking you,
Suresh.



List of 42 messages in thread
TopicAuthorDate
Measuring CR of Reed Switches.            01/01/70 00:00      
   Contact resistance?            01/01/70 00:00      
   Correction : Sorry its 10mV to 2500mV            01/01/70 00:00      
   Voltage or current, pick one            01/01/70 00:00      
      I can choose Test current as 10mA            01/01/70 00:00      
         typical constact resistance ?            01/01/70 00:00      
      yes, but            01/01/70 00:00      
         No CR when closed?            01/01/70 00:00      
            If this was possible, you would not need            01/01/70 00:00      
               current source with series resistor at            01/01/70 00:00      
                  Yes            01/01/70 00:00      
                  constant current source            01/01/70 00:00      
                  V=IR            01/01/70 00:00      
                     Specs & Description            01/01/70 00:00      
                  resistor ?            01/01/70 00:00      
                     Current source circuit for CR measuremen            01/01/70 00:00      
                        Why not using...            01/01/70 00:00      
                        Kind of            01/01/70 00:00      
                           And...            01/01/70 00:00      
                              7805 and get 10mA and 100mA            01/01/70 00:00      
                              reply - thermo-potentials            01/01/70 00:00      
                                 since you work for the manufacturer            01/01/70 00:00      
                                 Chopper            01/01/70 00:00      
                                    Chopper schematic            01/01/70 00:00      
                                       Thanks very much Kai.            01/01/70 00:00      
                                       Reply : Chopper Schematic            01/01/70 00:00      
                                          Answers            01/01/70 00:00      
                                             what about a chopper stabilized op-amp?            01/01/70 00:00      
                                                Yur.            01/01/70 00:00      
                                                Yes, but...            01/01/70 00:00      
                                             AC components , VCR, DCR            01/01/70 00:00      
                                                Answers            01/01/70 00:00      
                                                   Demodulation?            01/01/70 00:00      
                                                      This would be the Lock-in scheme            01/01/70 00:00      
                                                   Average Value, VCR & DCR Calculation            01/01/70 00:00      
                                                      Quite simple            01/01/70 00:00      
                                             Analysis for Usig o/p            01/01/70 00:00      
                                                Answers            01/01/70 00:00      
                                                   I thank you very much Kai            01/01/70 00:00      
                                                      Test Condition: 10mA, 50mV            01/01/70 00:00      
                                                         Switching condition            01/01/70 00:00      
   Remember Ohm's law?            01/01/70 00:00      

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