I have a vibrating alarm clock that goes under my pillow that is plugged into the wall. Can I use such an on shabbos to wake myself up? Is it better to get an alarm clock that is battery operated that vibrates? Or are they all muktzeh?
Answer:
I don’t see a problem of using the alarm clock to wake yourself up. If the clock functions with a lit display, there would be a problem of moving it while the lit display is on.
Sources: See Tzitz Eliezer 9:24