Best way to suppres inductor(relay coil) transients?

[guyaneseboy]

The reason that I suggest seperate supplies is to isolate the logic from the power circuit. As soon as a heavy load is switched even with RC snubbers,
varistors etc. the circuitry will start to fail again! Try switching 10 amps/120VAC RMS...

The optocoupler only improves the coil to contact isolation and will alieviate interference. A good quality relay and a relay driver (ULN280x seies) should suffice. KEEP the power return ground seperate from the logic ground and tie only at a single point!!!

Guyaneseboy

 

[artem]

I did not understand how the logic could fail if relays are operated from 48V that means separate power for logic and relays . Is there something temporary bjt c-b break when relay is off ?

 

[Regnum]

I did not understand how the logic could fail if relays are operated from 48V that means separate power for logic and relays . Is there something temporary bjt c-b break when relay is off ?

Elementary Watson, ...seyyah said ground tracks weren't separated

Regards

 

[e_eja]

try to separate digital gropund and analog ground, ihave same probl;em with this grounding and this teknique working for me