The invention discloses a
grain moisture online detection circuit. The
grain moisture online detection circuit comprise a power supply circuit, a constant-
current source circuit, a single-
chip microcomputer system, a
signal amplification circuit, a
Nixie tube display circuit, a motor anddrying
machine control system, a control knob, a key circuit and a temperature compensation circuit, wherein the
signal amplification circuit, the
Nixie tube display circuit, the motor and
drying machine control system, the control knob, the key circuit and the temperature compensation circuit are connected with the single-
chip microcomputer system through
data lines, the power supply circuit is connected with the other circuits, the constant-
current source circuit is formed by connecting a
voltage stabilizing circuit and a constant-
current source measuring circuit, and the output end of the constant-current source circuit is connected with the
signal amplification circuit. The
grain moisture online detection circuit has the advantages that the measuring response speed is high, precision can be as high as + / -0.5%, manpower source waste can be reduced, the production cost is reduced, measuring results are accurate and the practicality is high.