RF EMI Nosie Probllem

[shahsulax]

Hello

I am driving a Spark Ignition Circuit from my micro controller using a 12V DC supply thr a Relay.

However when the spark ignition system is powered using this 12V the micro controller sometimes shows erratic behaviour. Tried suppressing this noise using a 0.01 Cap + 100 Ohms Res Snubber network across this 12V but still that does not solve problem 100%.

Can any one suggest other alternatives for better performance !

S Shah

 

[milind.a.kulkarni]

in my view you need to have proper coupling for 12v and micro-controller-I/O 5v signal level....try to add the opto-coupler circuit ( which is generally used to interface from low power to high power circuits) in your circuit .....may help you to solve your problem

Good Luck

 

[shahsulax]

hi

Can't give Opto Isolation to my application for separate grounds.. as the application demands to run on Battery as well...

suggest other possible alternatives...

in my view you need to have proper coupling for 12v and micro-controller-I/O 5v signal level....try to add the opto-coupler circuit ( which is generally used to interface from low power to high power circuits) in your circuit .....may help you to solve your problem

Good Luck

 

[HTA]

Hello Shah,

please check if you have level shifter from the 5V micro I/O ports to the drive the 12V relay, as well as a free wheeling diode across the relay coil. Also watch ground or Vcc noise coupling into the micro supply. Here you find application how to drive relays with level shifting and current control: **broken link removed** .

Enjoy trouble shooting