| 摘要 |
PURPOSE:To improve the operational convenience by a method wherein the number of lit indicator lights is changed in response to the hot water delivery capacity in a gas water heater, which is equipped with a proportioning valve, a temperature sensing element and a plurality of indicator lights and the hot water delivery capacity of which is made continuously variable. CONSTITUTION:When a water heater is put into actuation, a large current flows in a proportioning valve 4, resulting in producing a high voltage across a resistor 7. Because an operational amplifier 18 acts as a voltage follower, its input voltage is outputted as it is, resulting in producing a high voltage across a resistor 8. Because operational amplifiers 19-22 act as voltage comparators and yet the output voltage of the operational amplifier 18 is higher as compared with the non-inverted input voltages of the operational amplifiers 19-22, the outputs of the operational amplifiers 19-22 are low, resulting in flowing current in LED's 23-26, which are respectively connected to the operational amplifiers 19-22, and consequently brightening LED's. On the other hand, when a small current flows in the proportioning valve 4 or the water heater burns on a small capacity, several LED's are lit, resulting in enabling indicate the capacity of the water heater. |
