problem in operating a power relay with the help of microcontroller

[devmania]

Hi Everyone,

I am here with a problem and i hope some one will help me out with this. I want to operate a power relay with the help of a microcontroller , the rating of the relay is 415v 12A . I have attached some files regarding the details of the relay i am going to use. Please suggest me what to do ?

Regards
Dev

 

[devmania]

Is it the same way how we control the 12v relay or the set up is different .

 

[Jon Chandler]

You'll need some kind of a driver circuit between the micro and the relay. One good way is:

Tip - Relays

 

[devmania]

Thanks for the reply sir.
will i be able to operate a power contactor?

 

[devmania]

My aim is to operate a contactor using microcontroller. The contactor will be connected to a 3-ph induction motor. The contactor coil need 24vDc and can operate at 415v Ac . So i wanted to know which microcontroller should i use and what interface should i make between controller and contactor.

 

[Jon Chandler]

You need to determine the coil current - probably for the 24V coil. Then design a driver circuit for it. Any micro will work but all will need some kind of driver.

 

[devmania]

Thanks for the reply sir, You asked me about the current for the coil so it is 12A . Can you please clear me about the driver ? How should i design the driver?

 

[Brevor]

You asked me about the current for the coil so it is 12A .

12 A seems high for the coil current. You need to measure the resistance of the coil and use Ohms law to determine the current it will draw at 24 VDC. Or just connect the coil to 24 VDC and measure the current. Then use a suitable transistor to drive the coil from the microcontroller output. Be aware you may need to keep all the microcontroller circuitry away from the 415 V. circuits or you may have problems with the microcontroller locking up or reseting when the motor starts.

 

[devmania]

Thanks Mr. Brevor. I will follow your words carefully. And please let me know some measure which i should take .
Thank you.