AN2131QC Reset when Solenoid valve switch off

[shahramza]

solenoid valve causing microcontroller reset

I'm useing AN2131QC ( 8051 base USB Microcontroller from Cypress) in a circuit that turns ON/OFF a solenoid valve. The valve coil works with 24V AC. I use a relay between the microcontroller and the solenoid valve. Eventually, when the valve switches, the microcontrollers resets.I am isulate micro from relay with optocupller pc123 and place capecitor with R in series across the solenoid valve load and it work better but after 10 min reset the micro again.
Coud you help me solve this problem?

Thanks alot

 

[vijaya_narayana]

just try to seperate the micro controller power supply and the relay power supply and ground.isolate both the grounds the relay and the micro i think this might solve the problem r use an inductor r a 0 ohm resistor for the power supply and the ground that leads to the relay