| 摘要 |
PURPOSE:To prevent food from putrefaction by inhibiting the temperature rise in an electric refrigerator when its door is kept open for a long time. CONSTITUTION:A commercial power supply system 1 supplies electric power to an electric refrigerator. A change over switch 2 operates as the door is opened and closed, and a chamber light 3 in the refrigerator is on while the door is open. A switch 4 is controlled by a control section, for example. A fan motor supplies cooled air into the refrigerator while the door is closed. A positive temperature coefficient resistor device 6, such as thermistor and a winding 7a of a relay 7 are coupled in parallel between the change over switch 2 and the chamber light 3. A contact C is connected to a terminal 'c' side of the change cover switch, and a contact 7b is connected to a terminal 'b' side. When the chamber light 3 is on for a long time, the resistor device 6 increases its internal resistance so that electric current flows though a winding 7a, thereby operating the relay 7. Therefore, if the door is open for a long time, the fan motor 5 operates and supplies cooled air into the refrigerator. |
