| 摘要 |
An electronic system for measuring the water level in domestic and industrial washing machines is disclosed, which may perform a continuous interpretation of a pressure range of 0kPa to 6kPa, this being translated into electric voltage levels which can be easily read by a microprocessor that controls the whole functions of the machine; in addition, the invention solves the problem related to the reliability of the obtained reading, by an auto diagnostic method that warrantees a correct output voltage in the system and detects an inner fault in the system. The system includes a pressure sensor, an instrumentation amplifier and the auto diagnostic signals. The Auto diagnostic characteristic solves the problem of detecting an inner fault in the circuits of the system in an easy manner, by means of introducing digital signals between the pressure sensor and the instrumentation amplifier, the microprocessor of the washing machine establishing an input and output sequence of electric signal s and criteria in the readout resulting from the instrumentation amplifier for determining the water level of the washing machine tank, also ensuring the circuit of the system to be operated in an optimum manner. |
