1. A bidirectional switching circuit comprising: a bidirectional non-linear device having a first amorphous silicon layer, a second amorphous silicon layer, an insulator layer sandwiched between said first and second amorphous silicon layers, a first electrode connected to said first amorphous silicon layer, a second electrode connected to said second amorphous silicon layer, first means coupled between said first electrode and said second electrode for applying a positive voltage of an absolute value of more than about 5 volts therebetween to turn said bidirectional switching device ON and to allow an electric current to flow in a direction from said first electrode to said second electrode, and second means coupled between said first electrode and said second electrode for applying a negative voltage of an absolute value of more than about 5 volts therebetween to turn said bidirectional switching device ON and to allow an electric current to flow in a direction from said second electrode to said first electrode.