unfortunately relays and solenoids operate with 30v AC and should react very quickly. How could I place diods?
in addition I have to say that relays and solenoids are on elctrical circuit that is separated from arduino. Arduino was powered through usb port of a pc and the set of relays used to control flipper counters are also optoisoled. So the only point in common between solenoids and arduino is the 220v power.