Apparatus for humidity detection
    1.
    发明授权
    Apparatus for humidity detection 失效
    湿度检测装置

    公开(公告)号:US4282480A

    公开(公告)日:1981-08-04

    申请号:US35331

    申请日:1979-05-01

    IPC分类号: G01N27/04 G01N27/22 G01R27/26

    摘要: Apparatus for humidity detection comprises a humidity sensing element, the electrostatic capacitance of which varies in accordance with the ambient humidity, a fixed capacitor, first and second pulse generating circuits respectively responsive to the sensing element and the capacitor, and a computing circuit responsive to pulses from the first and second pulse generating circuit. The sensing element and the fixed capacitor are respectively charged via resistors to produce first and second pulses in accordance with voltage across the sensing element and the capacitor. The difference between the widths of the first and second pulses is detected in the computing circuit to produce an output pulse indicative of the relative humidity, thereby compensating for undesirable infuenece due to dielectric loss in the sensing element so as to accurately measure humidity irrespectively of the ambient temperature.

    摘要翻译: 用于湿度检测的装置包括其静电电容根据环境湿度变化的湿度感测元件,分别响应于感测元件和电容器的固定电容器,第一和第二脉冲发生电路以及响应于脉冲的计算电路 从第一和第二脉冲发生电路。 感测元件和固定电容器分别通过电阻器充电,以根据感测元件和电容器两端的电压产生第一和第二脉冲。 在计算电路中检测第一和第二脉冲的宽度之间的差异,以产生指示相对湿度的输出脉冲,从而补偿由于感测元件中的介电损耗引起的不期望的不均匀性,从而精确地测量湿度,而不管 环境温度。

    Apparatus and method for controlling humidity
    2.
    发明授权
    Apparatus and method for controlling humidity 失效
    湿度控制装置及方法

    公开(公告)号:US4449188A

    公开(公告)日:1984-05-15

    申请号:US318552

    申请日:1981-11-05

    摘要: Apparatus for controlling humidity comprises a humidity sensing circuit including a humidity sensing element the electrostatic capacitance of which varies in accordance with the ambient relative humidity, and an air-conditioning system responsive to the sensed humidity. The humidity sensing element is charged and discharged repeatedly in accordance with a pulse train signal, and a period required for the voltage across the sensing element is measured during charging by a comparison between the voltage and a reference voltage. The pulse width or the reference voltage may be changed to select a desired reference humidity. A hysteresis characteristic may be given to render the operation of the circuit stable. When an SCR is controlled by the output signal of the humidity sensing circuit, the frequency of the pulse train signal is selected to be greater than four times the frequency of the voltage applied to the SCR.

    摘要翻译: 用于控制湿度的装置包括湿度感测电路,其包括其静电电容根据环境相对湿度而变化的湿度感测元件,以及响应于感测到的湿度的空调系统。 湿度感测元件根据脉冲串信号重复充电和放电,并且通过电压和参考电压之间的比较在充电期间测量感测元件两端的电压所需的周期。 可以改变脉冲宽度或参考电压以选择所需的参考湿度。 可以给出滞后特性以使电路的操作稳定。 当SCR由湿度检测电路的输出信号控制时,脉冲序列信号的频率被选择为大于施加到SCR的电压频率的四倍。