| 摘要 |
Each sensing element (22 to 26) in a transducer (30) has an analog output which controls the frequency of a variable frequency oscillator (16 to 19) which is energized through selector (14) when a reading is to be taken for the particular sensing device. The oscillator output is fed to a first counter (36) which counts a pre-settable total number of cycles to establish a variable time period corresponding to the value sensed. A second counter (38) is operated for the same time interval to count cycles from a high frequency clock source (40), the number counted being proportional to the analog signal from the sensing device. By changing the presettings of the first counter, the resolution of the transducer can be varied, enabling operation in different ranges with adequate accuracy. Also, where a number of sensing elements are used in a transducer, resolution can be selectively varied when digitizing readings from the different elements. |
