+ Post New Thread
Results 1 to 6 of 6
  1. #1
    Full Member level 1
    Points: 1,475, Level: 8

    Join Date
    Jul 2009
    Posts
    115
    Helped
    0 / 0
    Points
    1,475
    Level
    8

    How to check the state of the relay contacts?

    Hello Everyone,

    I would like to check the state of relay contacts, means everytime i want to check the status of the relay either its ON or OFF, insort by this feedback path circuit i want to know the status of the relay via microcontroller.

    Help to find out the suitable circuit for this.

    •   AltAdvertisement

        
       

  2. #2
    Full Member level 1
    Points: 1,862, Level: 10
    Achievements:
    7 years registered

    Join Date
    May 2012
    Location
    Turkey
    Posts
    109
    Helped
    23 / 23
    Points
    1,862
    Level
    10

    Re: How to check the state of the relay contacts?

    That can be done in several ways, here is one,
    Click image for larger version. 

Name:	2012-10-08-020.jpg 
Views:	9 
Size:	918.5 KB 
ID:	81179
    You should know the voltage of the NC pin and by choosing Rb you can drive the transistor and chose a proper Re to have 3v-5v to transfer the information to the pic's pin
    Last edited by tusemo; 8th October 2012 at 08:06. Reason: grammer



    •   AltAdvertisement

        
       

  3. #3
    Full Member level 1
    Points: 1,475, Level: 8

    Join Date
    Jul 2009
    Posts
    115
    Helped
    0 / 0
    Points
    1,475
    Level
    8

    Re: How to check the state of the relay contacts?

    what would be the values of resistors and transistors? i am using 12A 24VDC electromechanical relay and microcontroller operated on 5VDC

    - - - Updated - - -

    what would be the values of resistors and transistors? i am using 12A 24VDC electromechanical relay and microcontroller operated on 5VDC



    •   AltAdvertisement

        
       

  4. #4
    Full Member level 1
    Points: 1,862, Level: 10
    Achievements:
    7 years registered

    Join Date
    May 2012
    Location
    Turkey
    Posts
    109
    Helped
    23 / 23
    Points
    1,862
    Level
    10

    Re: How to check the state of the relay contacts?

    what is signal or power voltage to be controlled by the relay



  5. #5
    Member level 1
    Points: 1,120, Level: 7

    Join Date
    Aug 2010
    Location
    noida, india
    Posts
    36
    Helped
    0 / 0
    Points
    1,120
    Level
    7

    Re: How to check the state of the relay contacts?

    Quote Originally Posted by sr_raval View Post
    what would be the values of resistors and transistors? i am using 12A 24VDC electromechanical relay and microcontroller operated on 5VDC

    - - - Updated - - -

    what would be the values of resistors and transistors? i am using 12A 24VDC electromechanical relay and microcontroller operated on 5VDC
    What is the resistance of relay coil only then i can decide transistor and resistor.



    •   AltAdvertisement

        
       

  6. #6
    Full Member level 1
    Points: 1,475, Level: 8

    Join Date
    Jul 2009
    Posts
    115
    Helped
    0 / 0
    Points
    1,475
    Level
    8

    Re: How to check the state of the relay contacts?

    Resistance of relay coil is 1600 ohms, please go through attached datasheet of relay, consider 24VDC relay

    - - - Updated - - -

    Resistance of relay coil is 1600 ohms, please go through attached datasheet of relay, consider 24VDC relay
    Last edited by sr_raval; 10th October 2012 at 07:27.



--[[ ]]--