CN2128737Y

CN2128737Y - Capacitance-type sensor for moisture content

Info

Publication number: CN2128737Y
Application number: CN 92225951
Authority: CN
Inventors: 徐玉检; 刘琨
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-07-01
Filing date: 1992-07-01
Publication date: 1993-03-24
Anticipated expiration: 2002-07-01

Abstract

The capacitance-type sensor for moisture content of the utility model comprises an outer cylinder, an inner cylinder, an inner-built control delay circuit, an electronic control box of checking amplifying circuit, a level sensor, a discharge gate, a connecting rod and a weight. The inner walls of the inner cylinder and outer cylinder are coated with fluon to eliminate the electrostatic conglutination between the cylinder wall and materials. The discharge gate equips the weight to ensure the reliability of the discharge gate closing. The control delay circuit comprises a three-terminal regulated power supply, a timing integrated circuit, a negator circuit, a triode, a diode, an electric relay, a capacitance, a resistor and the level sensor. The checking amplifying circuit comprises a cylindrical capacitance, a reference capacitance, an analog switch, an operational amplifier, a high-frequency clock generator, the capacitance and the resistor.

Description

Capacitance-type sensor for moisture content

The utility model relates to a kind of condenser type moisture sensor, is applicable to the online or off-line measurement of powdery (as flour, starch, cement) and granular material water cut.

Existing condenser type moisture sensor, its value of measuring is the oscillation frequency signal that lc circuit produced, its weak point is: owing to be subjected to the influence of oscillation frequency, waveform and ambient temperature, and cause the error of the value of measuring bigger.

The purpose of this utility model is to overcome above-mentioned weak point of the prior art and a kind of value of measuring is provided is the condenser type moisture sensor of voltage signal.

The purpose of this utility model can reach by following measure: the utility model is made up of Electronic Control Box, level sensor, Dump gate, connecting rod and the weight of urceolus, inner core, interior dress control delay circuit and detection amplifying circuit.The equal coated Buddhist nun of inner core inside and outside wall and outer tube inner wall fluon, in order to eliminate the static adhesion of barrel to material, Dump gate is furnished with weight, and is reliable to guarantee closing of Dump gate.

The control delay circuit is made up of three-terminal voltage-stabilizing power supply 7812, three timing ic 5G555, two NAND gate circuit 74HCOO, two triode 3DG12, six diode 2CK, three relays, eight electric capacity, nine resistance and level sensor.Fourth ₁One group of contact read the switch of signal, fourth as control ₂, fourth ₃One group of contact parallel connection after control electromagnet adhesive and release movement.

Detecting amplifying circuit is made up of tubular electric capacity, reference electric capacity, analog switch, operational amplifier, high-frequency clock pulse generator, electric capacity and resistance.The high-frequency clock pulse generator comprises three phase inverters, crystal oscillator, electric capacity and resistance.

The drawing of accompanying drawing is described as follows:

Fig. 1 is a structural representation of the present utility model.

Fig. 2 is the electrical schematic diagram of control delay circuit of the present utility model.

Fig. 3 is the electrical schematic diagram of detection amplifying circuit of the present utility model.

The utility model is described in further detail below in conjunction with embodiment and accompanying drawing: referring to Fig. 1, Fig. 2 and Fig. 3, the utility model is by urceolus 1, inner core 2, Electronic Control Box 3, level sensor K ₁, discharging electromagnet 5, Dump gate 6, connecting rod 7 and weight 4 form.The utility model machine and electricity are installed on one and form electromechanical integrated structure, adopt double-barrel structure, the equal coated Buddhist nun of inner core inside and outside wall and outer tube inner wall fluon, and in order to eliminate the static adhesion, Dump gate is furnished with weight, and is reliable with the switch of guaranteeing Dump gate.

Electronics partly comprises the control delay circuit and detects amplifying circuit, all is loaded in the Electronic Control Box.

The electrical schematic diagram of control delay circuit is seen Fig. 2, and mark is as follows among the figure:

U ₁Be three-terminal voltage-stabilizing power supply 7812,

U ₂, U ₃, U ₄Be timing ic 5G555(NE555),

U ₅, U ₆Be NAND gate circuit 74HCOO,

T ₁, T ₂Be triode 3DG12,

D ₁-D ₆Be diode 2CK,

J ₁, J ₂, J ₃Be relay,

C ₁-C ₈Be electric capacity,

R ₁-R ₉Be resistance,

K ₁Be level sensor.

J ₁One group of contact read the switch of signal as control,

J ₂, J ₃One group of contact parallel connection after control electromagnet adhesive and release movement.

The control delay circuit is made up of three-terminal voltage-stabilizing power supply 7812, three timing ic 5G555, two NAND gate circuit 74HCOO, two triode 3DG12, six diode 2CK, three relays, eight electric capacity, nine resistance and level sensor.When material in the tube reaches the height that gives elder generation's regulation, level sensor K ₁Send material level and " expire " signal, K ₁Closure, J ₁Adhesive is sent and is read signal, starts U simultaneously ₂, U ₂Delay time (present embodiment choose 0.1-1 second) by R ₃C ₄Time constant decision, this delay time, is calculated the mean value conduct by computing machine and is read signal when sending one group of signal for the usefulness of sending one or one group signal.Owing to the control of level sensor, just can guarantee the sampling holder of computing machine or conventional controller, when detecting the moisture content value, its controlling level is consistent at every turn.After this delay time arrives, U ₂Output terminal become low level, and material level and " expire that " signal is through U ₆Start U ₃, this moment U ₃Be output as high level, T ₁Conducting, J ₂Adhesive, discharging electromagnet energising, Dump gate is opened discharging, and delay time (present embodiment choose 1-120 second) is for the usefulness of discharging, after delay time arrives, U ₃Output terminal recovers low level, and Dump gate is closed, at this moment J ₂One group of normally closed contact closure, start U ₄, J ₃Adhesive, discharging electromagnet adhesive 1-2 were once more unclamped after second, and this 1-2 second is once promptly realized rapping one usefulness of taking second place for the very fast unlatching of Dump gate, to lay down the salvage stores that invests on Dump gate and the wall, closes Dump gate then.After this, continuity constantly repeats the above-mentioned process that reads signal, discharging and rapping of sending.

Detect the electrical schematic diagram of amplifying circuit and see Fig. 3, mark is as follows among the figure:

C ₁₁Be tubular electric capacity,

C ₁₂Be reference electric capacity,

K ₂, K ₃Be analog switch,

A ₁-A ₄Be operational amplifier,

10 is the high-frequency clock pulse generator,

8 is phase inverter,

9 is crystal oscillator (three),

C ₉, C ₁₀, C ₁₃And C ₁₄Be electric capacity,

R ₁₀-R ₁₄Be resistance.

Detect amplifying circuit by the tubular capacitor C ₁₁, the reference capacitor C ₁₂, analog switch K ₂, K ₃, operational amplifier A ₁-A ₄, high-frequency clock pulse generator 10, electric capacity and resistance forms.High-frequency clock pulse generator 10 comprises transistor oscillator 9, electric capacity and the resistance of three

phase inverter

8,8 megahertz thatches.Inner core 2 and urceolus 1 are formed the tubular capacitor C ₁₁, its electric capacity changes with the difference of material moisture content in the tube.With oscillation frequency is that the high-frequency clock pulse generators of 8 megahertz thatches is controlled analog switch K ₂And K ₃, K ₂And K ₃One termination+5 volt power supply, an end meets A respectively ₁And A ₂Input end, operational amplifier A ₁And A ₂Be connected into the current amplifier form, K switch ₂And K ₃Capacitor C during the energized end ₁₁And C ₁₂Charging, the switch connection operational amplifier A ₁And A ₂The time, capacitor C ₁₁And C ₁₂Pass through operational amplifier A ₁And A ₂Two input ends discharges, this discharge current amplifies through computing and becomes differential voltage signal, two-way differential voltage signal enters differential amplifier A simultaneously ₃, detect difference through amplifier A ₄Amplify back output, can directly enter computer system and control computing, also can be as the control signal of conventional controller.

The utility model contrast prior art has following advantage: certainty of measurement is higher, can eliminate the static adhesion of material, has realized electromechanical integration.

Claims

A kind of condenser type moisture sensor of measuring powdery and granular material water cut, it is characterized in that, by urceolus, inner core, the Electronic Control Box of interior dress control delay circuit and detection amplifying circuit, level sensor, Dump gate, connecting rod and weight are formed, the equal coated Buddhist nun of inner core inside and outside wall and outer tube inner wall fluon, Dump gate is furnished with weight, the control delay circuit is by three-terminal voltage-stabilizing power supply 7812, three timing ic 5G555, two NAND gate circuit 74HCOO, two triode 3DG12, six diode 2CK, three relays, eight electric capacity, nine resistance and level sensor are formed, detect amplifying circuit by tubular electric capacity, reference electric capacity, two analog switches, three operational amplifiers, the high-frequency clock pulse generator, electric capacity and resistance are formed, and the high frequency clock generator comprises three phase inverters, the crystal oscillator of 8 megahertz thatches, electric capacity and resistance.