Controller is Resetting

[ragav777]

Hi, I am controlling 6A coil contactor, using a 12V relay by the micro controller.

Circuit is working fine even there are noises, but when i connect the ground of CRO to the Circuit ground, when the contactor is energized, the controller resets.

Is there any solution for this..

 

[andre_luis]

ragav,

Inductive components ( mottors, Contactores, Solenoids, and even relays ) adds big induced spikes at board, mainly if is at protoboard.
Check tracks distances ( if at PCB ), or wires ( if at PROTO ).

Also is important take special aptention to uC power supply, if it is filtering noises properly.

+++

 

[ragav777]

Yes, tracks are ok. There is enough gap between tracks.

I added 0.1uF disc capacitors nearer to all Vdd pins of uC, Is there necessary to put some value of electrolytic capacitor nearer to the controller..

Thanks..

 

[cameo_2007]

6A is what? the coil current? and is the contactor coil DC or AC ?
And what is the load that you switch on with your contactor?

you need to put a surge protector or snubber circuitrys across the Contactor coil.

 

[ragav777]

6A is what? the coil current? and is the contactor coil DC or AC ?
And what is the load that you switch on with your contactor?

you need to put a surge protector or snubber circuitrys across the Contactor coil.

Yes, I have put Snubber across the coil. R = 100 Ohms and C = 47nF

Contactor is 3Phase and coil is 230VAC , and the motor starting current is 1450A, which is given through contactor..