METHOD OF SUPPLYING POWER VENT/DIRECT VENT WATER HEATER BACKUP POWER WHEN THE MAIN POWER IS OFF AND THE BACKUP POWER SUPPLY SYSTEM THEREOF

摘要

A backup power supply system of a water heater includes a power transforming device and a controller. The power transforming device generates a DC current with an initial voltage through sensing the temperature change under a low battery condition. The controller examines the initial voltage of the DC current and gives command to which device to supply power to the water heater or to amplify the initial voltage of the DC current for maintaining the water heater's normal work.