An intelligent control circuit of a geothermal heating system for agricultural greenhouses

Abstract

The invention relates to an intelligent control circuit of an agricultural greenhouse, in particular to an intelligent control circuit of an agricultural greenhouse geothermal heating system. The intelligent control circuit comprises a power supply circuit, a temperature control circuit, a water shortage auto-stop circuit, a control output circuit and an open-phase protection circuit. The upper limit temperature signal end of the temperature control circuit is connected to the second input end of an OR gate c through an isolating diode a; the lower limit temperature signal end of the temperature control circuit is connected to the input end of an OR gate a; the output end of the OR gate a is connected to the first input end of the OR gate c; the output end of the OR gate c is connected to the input end of an OR gate b; the output end of the OR gate b is connected to the second input end of the OR gate c through an isolating diode b; the output end of the OR gate c is connected to a base of a triode a through a drive resistor a; a collector of the triode a is connected to a first relay coil; a normally open contact of a first relay is connected between the control end a and the control end b. The intelligent control circuit allows the agricultural greenhouse geothermal heating system to automatically run, and the environment good for growth of fruits and vegetables is created for the agricultural greenhouse.

Description

technical field [0001] The invention relates to an electronic circuit, in particular to an intelligent control circuit for an agricultural greenhouse. Background technique [0002] The agricultural greenhouse is a frame-covered structure with thermal insulation properties. Its appearance allows people to eat off-season vegetables and fruits. Generally, agricultural greenhouses use a bamboo structure or a steel structure frame, covered with one or more layers of thermal insulation plastic film, thus forming a greenhouse space. The outer film can well prevent the loss of carbon dioxide produced by the growth of vegetables inside, so that the shed has a good heat preservation effect. [0003] During winter nights or rainy weather, the temperature in the agricultural greenhouse is too low, which is not conducive to the growth of fruits and vegetables, affecting the quality and yield of fruits and vegetables. The use of geothermal heat to heat agricultural greenhouses is of gre...

AI Technical Summary

Problems solved by technology

[0004] In agricultural greenhouses, due to the humid environment, the power supply lines and switchgears often have poor contact, which can easily cause phase loss. If the three-phase motor runs without phase, it will not work normally, and the motor winding will burn out soon. After the motor burns out, it needs Replacement and repairing will not only cause economic losses, but also affect production. Therefore, a protection circuit that can effectively prevent three-phase motors from running without phase is needed

The existing phase loss protection device has the disadvantage that it cannot effectively protect the three-phase motor or has the disadvantage of complex circuit structure

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