| 摘要 |
PURPOSE:To permit to detect the temperature of hot-water in a bathtub and recognize the heat-up of the hot-water automatically by providing at least two sets of temperature detectors on a chord for a water discharging plug. CONSTITUTION:The temperature of the upper temperature detector 13 is saturated when a time has elapsed. On the other hand, the temperature of the lower temperature detector 14 increases slowly but it is increased suddenly after a given time has elapsed since high-temperature layer of water, spread near the surface of water, descends in a condition different from before. Respective outputs of two sets of temperature detectors are inputted into a differential amplifying circuit 17 through amplifying circuits 15, 16 and an average temperature is obtained by an average value operating circuit 18 to compare the output with the value of preset temperature in a temperature setter 19 by a comparing circuit 20 while the conversion of the output is detected by differentiating the output of the differential amplifying circuit 17 in a differentiating circuit 21 and heat-up of the hot-water may be detected by ANDing of the output between the comparing circuit 20. |
