| 摘要 |
<p>PURPOSE:To eliminate necessity of 100V source by a method wherein a timer circuit is provided to output signals to a microcomputer, and the microcomputer output a signal to a heater power supply control circuit instantly is heater-on conditions is satisfied and power supply is restarted within a specified time period after the midnight power supply is started. CONSTITUTION:At the start of midnight electric power supply, the reference voltage VA rises at one, but the electrical double layer capacitor signal voltage VB rises later. And, the reference voltage VA is set at a voltage between the electrical double layer capacitor signal voltage VB8 8 hours after the midnight power is cut off and the electrical double layer capacitor signal voltage VB16 16 hours after. Therefore, the output of a timer is L0 until the electrical double layer capacitor signal voltage VB exceeds the reference voltage VA and becomes HI when exceeding. When a microcomputer 3 is reset during L0 to perform arithmetic operation upon the input signals from a hot-water detecting circuit 5 and a hot-water temperature setting circuit 6 and output an HI signal through a timer circuit 20, a transistor 7a of a heater power control circuit 7 is turned on causing a relay 7b to be turned on to start power supply to the heater 8 after peak shift is carried out corresponding to the results of the above arithmetic operation.</p> |
