| 摘要 |
<p>PURPOSE:To extend the range of application, by using moisture sensor and two temperature sensors, in the prediction circuit predicting and alarming the dew for the rotary drum for video tape recorder. CONSTITUTION:The moisture sensor is connected to the comparator via the moisture-voltage conversion circuit and thermister, and the atmosphere temperature sensor and the temperature sensor for dewed body are connected to the comparator via the temperature difference amplifier. Thus, after the moisture in the atmosphere induclding dewed body detected with the moisture sensor is converted into a voltage, temperatue compensation is made by the thermister to compensate the change in the dew temperature difference at a constant moisture and the result is input to the comparator. Further, the output difference between the atmosphere temperature sensor and dewed body temperature sensor is amplified and input to the comparator, and dew prediction signal is output with the relation between the moisture signal and temperature difference signal. Accordingly, the operation characteristics of each sensor is matched to the vapor pressure curve and the temperature difference output signal is compressed or expanded to enable freely to select the curve predicting the danger of dew, allowing to achieve desired objective.</p> |
