| 摘要 |
PURPOSE:To prevent a battery from being discharged by automatically turning off a switch by means of the change of the coil exciting force and by turning on an alarm lamp when the power voltage of a car-mounted refrigerator is dropped to an value equal to or less than a preset value. CONSTITUTION:An automatic power cut switch 10 is provided on a power cord 4 between a battery and a plug 3, so that when the voltage of a power supply is high a coil 15 is excited with a strong force and a contact point 14 gets into contact with a contact point 12, then a current flows through a cooling unit 1 to operate it. When a car is stopped and an engine-mounted generator is not operated, the voltage of the power supply 11 is dropped and the exciting force of a coil 15 is reduced, thereby the contact point 14 is removed from the contact point 12 to get into contact with a contact point 13. Accordingly, the cooling unit 1 becomes nonconducting and is not operated. Since the contact point 14 gets into contact with the contact point 13, a current flows through an alarm lamp 16 to turn it on. |
