| 摘要 |
PURPOSE:To make the device small in size, low in cost and simple in constitution by providing a permanent magnet with apparent specific gravity less than that of hot water and elevating by the elevation of a floating hit water plane, and a reed switch which opens/closes a contact by the permanent magnet when the hot water plane arrives at an upper or lower limit position. CONSTITUTION:A transparent nonmagnetic pipe shape hot water introduction pipe 27 connected via a U-shape manifold 26 and rolling from the lower side from a descent limit position 9B to the upper side from an ascent limit position 9A and whose intermediate part is thick is provided at a drain 18 whose one terminal is connected to the bottom of a hot water tab 24 via a drain cock 19. The permanent magnet 29 embedded in a float 28 and with the apparent specific gravity less than that of the hot water is provided in the thick intermediate part of the hot water introduction pipe 27, and the reed switch 30 at the ascent limit position 9A and the descent limit position 9B, and when the hot water in the hot water tab 24 which comprises an in-hot water tab hot water plane detector 25 is decreased at every supply of tea and the hot water plane arrives at the descent limit position 9B, the permanent magnet 29 embedded in the float 28 arrives at a lower limit, which closes the contact of the reed switch 30, and de-energized a heater 20, and when the hot water plane arrives at the ascent limit position 9A, the contact of the reed switch 30 is opened, which energizes the heater 20. |
