Automatic control device for irrigating, spraying and sprinkling

Claim 2

An automatic control device for controlling irrigation, spraying and sprinkling of cultures, by controlled release of water therefor, comprising in combination: an electric sensor of ambient lighting; an electric sensor of outside temperature; means for establishing electrical reference values for ambient lighting and outside temperature; comparator means for respectively comparing the outputs of said sensors with said reference values; a logic circuit responsive to a set of predetermined conditions of the outputs of said comparator means; relay means operated from the output of said logic circuit for controlling the said release of water; and means activated from the output of said circuit for resetting said relay means after a determined length of time following their activation.

Claim 3

Device according to claim 1, including a further electric sensor, an electrical reference value thereof and comparator means therefor for sensing the moisture condition of the soil, the output of the said further comparator means being connected to a further input of said logic circuit.

Claim 4

Device according to claim 1, wherein said logic circuit is comprised of an AND circuit of the outputs of said comparator means.

Claim 5

Device according to claim 1, which further comprises a first time-constant circuit activated from the said output of said logic circuit and means controlled from said first time-constant circuit for resetting said relay means after a length of time substantially equal to its time constant from its activation.

Claim 6

Device according to claim 4, wherein said first time-constant circuit includes condenser charging means activated from the clOsure of a work contact in said relay means, and said means for resetting back said relay means include means responsive to the full charge of said condenser means for opening the energization circuit of said relay means.

Claim 7

Device according to claim 1, which further comprises a second time-constant circuit activated by the reset of said relay means and means controlled from said second time-constant circuit for inhibiting activation of said relay means during a time interval substantially equal to the time constant thereof.

Claim 8

Device according to claim 6, wherein said second time-constant circuit includes condenser charging means activated from a closure of a work contact in said relay means, condenser discharging means controlled by the reset to rest of a contact in said relay means and said means for inhibiting activation of said relay means includes further relay means cutting the energization circuit of said relay means up to the complete discharge of said condenser means.

Claim 9

Automatic device for controlling the water release in irrigation, spraying and sprinkling equipments for cultures, comprising in combination: a plurality of electric sensor means, each adapted to measure the value of a distinctive environmental parameter to intervene in a decision of water release; a corresponding plurality of transistor threshold circuits respectively driven from the outputs of said sensor means, each of said circuits including means for adjustably defining a reference threshold value; a logic circuit having as many inputs as there are transistor threshold circuits respectively connected to the outputs of said threshold circuits; a circuit for temporary energization for a relay coil in on-off control from the output of said logic circuit; and contacts of said relay for further controlling water releasing means.

Claim 10

Automatic device for controlling the water release in irrigation, spraying and sprinkling equipments for cultures, comprising in combination: a plurality of electric sensor means, each adapted to measure the value of a distinctive environmental parameter to intervene in a decision of water release; a corresponding plurality of transistor threshold circuits respectively driven from the outputs of said sensor means, each of said circuits including means for adjustably defining a reference threshold value; a logic circuit having as many inputs as there are transistor threshold circuits respectively connected to the outputs of said threshold circuits; a circuit for temporary energization for a relay coil in on-off control from the output of said logic circuit; and contacts of said relay for further controlling water releasing means.

Claim 11

Device according to claim 8, wherein said logic circuit includes as many emitter-collector paths of transistor stages as there are threshold circuits, serially connected with the said energization relay coil across a DC supply.

Claim 12

Device according to claim 8, wherein at least one of said sensor means senses the ambient temperature parameter, at least one of said sensor means senses the ambient lighting parameter, and at least one of said sensor means senses the moisture of the soil at substantially the level of the roots of the cultures.

Claim 13

Device according to claim 9, wherein said series circuit further includes a transistor stage controlled from a resistance-condenser time-constant circuit and wherein a work contact of said relay controls the activation of said time-constant circuit, for blocking the energization of said relay after a predetermined time interval from the actuation to work thereof.

Claim 14

Device according to claim 9, wherein said series circuit further includes a further transistor stage controlled from a further relay actuated from a further time-constant circuit of the resistance-condenser type, means including a work contact of said water release controlling relay for charging said condenser, and means including a rest contact of said water release controlling relay for discharging said condenser through the energization coil of said further relay for blocking said further transistor stage during the said discharge.