I want to connect a bell switch to a monostable multivibrator using timer IC 555, but the bell switch is on 230V ac and the Monostable Multivibrator on DC Supply. Can I connect the Normally Closed (N.C.) contact of the bell switch to the Trigger terminal of the multivibrator and the Normally Open (N.O.) contact of bell switch (which is connected to 230V ac) to the ground of IC 555? OR is there any other possible technique?