| 摘要 |
PURPOSE:To display impossibility of designated operation, when a setting value of hot-water supplying temperature and hot-water supplying flow exceed the specific capability limitation of a water heater, by a method wherein a required amount of heat for the desired hot-water supplying temperature is obtained by multiplying a water flow supplied to the water heater main body by a temperature difference between said water temperature and a setting hot-water supplying temperature, then said required amount of heat is checked whether or not it is included in the range of capability limitation designated in advance. CONSTITUTION:A switch circuit which operates ON or OFF a deviation amplifier composed of resistances R1-R4 and an operation amplifier U1, and a transistor Q1 provided at the output side of the operation amplifier U1, according to the pulse of a flow signal (a) supplied from a flow sensor 6, and a filter circuit composed of diodes D1, D2, resistances R5, R6 and a capacitor C1 connected at the output side of the operation amplifier U1, operate as a multiplying circuit which calculates an electrical voltage Ef proportional to the result multiplied a deviation between supplying water temperature and setting hot-water temperature by a water flow. The result of said multiplication indicates the required amount of heat for heating the water up to the designated temperature in the water heater main body 1. Said electrical voltage Ef is compared with each upper limit electrical voltage EH and lower limit electrical voltage EL in comparators U2 and U3. |
