Electric appliances on Shabbat

Hi,

Electric appliances are not considered a kli shem'lachto l'issur [an implement which is normally used for Shabbat-prohibited purposes] by dint of its electric current. It is only considered a kli shem'lachto l'issur if its function is to be used for Shabbat-prohibited tasks [i.e. a hair dryer, as opposed to a clock].

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 5:23)

Have a great day,
Mordechai