| 摘要 |
The water heater includes a heating arrangement, a power control arrangement controlling the power supply of the heating arrangement, and a sensor arranged in a water supply to determine a water supply quantity. The sensor is a flow sensor which produces a sensor signal monotonously dependent on, or preferably proportional to, a volume current or mass current. A supervision circuit is coupled with the flow sensor, which receives and evaluates the sensor signal, whereby the supervision circuit records signal changes which are characteristic for the appearance of air or air-water mixtures in the water supply, and produces a switch-off signal at an output at detecting of these signal changes. The power control arrangement is coupled with the output of the supervision circuit and interrupts the current supply to the heating arrangement at reception of the switch-off signal. |
