Abstract: An electronic device comprising a light sensor, a plurality of inputs and outputs, and an integrated circuit provides discrimination from logic input detection signals to generate output signals. The input detection signals are received from slotted opto-interrupter devices installed at a door and a lid of a hopper and also from a light sensor. Electric locks responsive to the output signals are installed at the door and the lid while an electronic relay is installed at a light switch and power socket. The device will not allow the hopper's lid to be opened if the room's door is open and/or the room's light is turned on. When the hopper's lid is opened the door automatically locks and electric power to the light switch and power socket is interrupted. When the hopper's lid is open and the light switch is turned to the ON position, the light will not turn ON until the hopper's lid is closed.