초록 ▼

A system for automatically controlling a lawn watering system responsive to the moisture content of the soil includes at least one moisture sensor which supplies a signal to a moisture controller to actuate a water supply valve. The moisture sensor has a casing containing two electrodes and an insul

A system for automatically controlling a lawn watering system responsive to the moisture content of the soil includes at least one moisture sensor which supplies a signal to a moisture controller to actuate a water supply valve. The moisture sensor has a casing containing two electrodes and an insulating body of synthetic fibers which provide a path to transfer water from the soil to the electrodes.

대표청구항 ▼

[ What is claimed:] [7.] A moisture controller for use in an automatic watering system comprising:a zero-crossing switch capable of receiving a dc voltage corresponding to an amount of moisture in a predetermined area of soil and of providing an output control signal to an output load in response to

[ What is claimed:] [7.] A moisture controller for use in an automatic watering system comprising:a zero-crossing switch capable of receiving a dc voltage corresponding to an amount of moisture in a predetermined area of soil and of providing an output control signal to an output load in response to said dc voltage;an input circuit for receiving an ac voltage input and for providing said dc voltage to said zero-crossing switch, wherein said dc voltage corresponds to said ac voltage; anda hysteresis circuit coupled to said zero-crossing switch, wherein said hysteresis circuit prevents an oscillation of said output load in response to a drop in said dc voltage supplied to said zero-crossing switch due to an actuation of said output load.