Irrigation controller with analog data input devices
    5.
    发明授权
    Irrigation controller with analog data input devices 失效
    灌溉控制器带模拟数据输入设备

    公开(公告)号:US5414618A

    公开(公告)日:1995-05-09

    申请号:US172518

    申请日:1993-12-21

    摘要: An improved irrigation controller of solid state design utilizes a microcomputer which retains and executes a watering schedule. A plurality of analog data input devices are provided with one input device being assigned to input one value of at least one watering schedule parameter having a number of possible values. Each analog data input device comprises a potentiometer, connected between high and low reference voltages, which has a variable output voltage determined by the setting or position of the input device on the controller housing, with different output voltages representing different values of the parameter. The output voltage is determined by charging a capacitor using a constant current source and by timing how long it takes the capacitor to reach the output voltage. The same capacitor is used for all of the analog data input devices to remove any variability in how different capacitors charge. In addition, the actual instantaneous high and low reference voltages are also read when the output voltage of at least one analog data input device is read.

    摘要翻译: 一种改进的固态设计灌溉控制器利用一台保留并执行浇水时间表的微型计算机。 多个模拟数据输入装置被提供有一个输入装置被分配以输入具有多个可能值的至少一个浇水进度参数的一个值。 每个模拟数据输入装置包括连接在高和低参考电压之间的电位器,其具有由控制器壳体上的输入装置的设置或位置确定的可变输出电压,具有表示不同参数值的不同输出电压。 输出电压通过使用恒流源对电容器充电以及通过定时电容器达到输出电压所需的时间来确定。 所有模拟数据输入设备都使用相同的电容,以消除不同电容器充电的变化。 此外,当读取至少一个模拟数据输入装置的输出电压时,也读取实际的瞬时高和低参考电压。