CN211878649U - Paper money double-sheet detection device and signal processing circuit thereof - Google Patents
Paper money double-sheet detection device and signal processing circuit thereof Download PDFInfo
- Publication number
- CN211878649U CN211878649U CN202020478939.XU CN202020478939U CN211878649U CN 211878649 U CN211878649 U CN 211878649U CN 202020478939 U CN202020478939 U CN 202020478939U CN 211878649 U CN211878649 U CN 211878649U
- Authority
- CN
- China
- Prior art keywords
- resistor
- electrode plate
- operational amplifier
- amplifying circuit
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The utility model discloses a paper money re-opening detection device and a signal processing circuit thereof, which comprises a square wave generator, a signal processing circuit, a microprocessor, a transmitting electrode plate and a receiving electrode plate, wherein the transmitting electrode plate and the receiving electrode plate are arranged oppositely at intervals; the square wave generator is connected with the transmission electrode board electricity, square wave generator output square wave voltage gives the transmission electrode board, signal processing circuit includes coupling amplifier circuit, sample hold circuit, biasing amplifier circuit, coupling amplifier circuit's input is connected with the receiving electrode board electricity, coupling amplifier circuit's output is connected with the input electricity of sample hold circuit, the output of sample hold circuit is connected with biasing amplifier circuit's input electricity, biasing amplifier circuit's output is connected to microprocessor through AD converting circuit, the utility model discloses utilize the change of electrolyte thickness between the electric capacity polar plate to lead to the electric capacity change to the coupling voltage change that makes to correspond judges paper currency to be opened again.
Description
Technical Field
The utility model relates to a paper currency detection area especially relates to a paper currency detection device and paper currency detection device's that opens again signal processing circuit.
Background
Aiming at the currency counting and detecting machine equipment on the market, the identification sensor is arranged in a currency conveying channel, when the currency passes through the corresponding sensor, the sensor acquires relevant signal characteristics, and whether the currency is true or suspected is judged through certain algorithm processing.
Due to the particularity of the paper money detection, a general detection device usually comprises a complex processing circuit or needs a complex transmission structure to be matched and completed, so that a large structural area is occupied, the installation is also complex, and the cost is high.
Disclosure of Invention
An object of the utility model is to overcome prior art's defect, provide a paper currency detection device that opens again, it leads to the capacitance change with the change of capacitor electrode inter-plate electrolyte thickness to the coupling voltage who makes the correspondence changes, then judges that paper currency opens again.
The utility model discloses a realize like this: the utility model discloses a paper money re-opening detection device, which comprises a square wave generator, a signal processing circuit, a microprocessor, a transmitting electrode plate and a receiving electrode plate, wherein the transmitting electrode plate and the receiving electrode plate are arranged oppositely at intervals, so that a paper money passage is formed between the transmitting electrode plate and the receiving electrode plate; the square wave generator is electrically connected with the transmitting electrode plate and is used for outputting square wave voltage to the transmitting electrode plate, and when paper money passes through a paper money passing channel between the transmitting electrode plate and the receiving electrode plate, the square wave voltage of the transmitting electrode plate is coupled to the receiving electrode plate; the receiving electrode plate is connected to the microprocessor through the signal processing circuit; the signal processing circuit comprises a coupling amplifying circuit, a sampling holding circuit and a bias amplifying circuit, wherein the input end of the coupling amplifying circuit is electrically connected with the receiving electrode plate, the output end of the coupling amplifying circuit is electrically connected with the input end of the sampling holding circuit, the output end of the sampling holding circuit is electrically connected with the input end of the bias amplifying circuit, and the output end of the bias amplifying circuit is connected to the microprocessor through an AD (analog-to-digital) conversion circuit. The result judged by the microprocessor is displayed by a display screen, and can be prompted by other alarm devices.
Further, the coupling amplifying circuit comprises a capacitor C12 and an operational amplifying circuit, the capacitor C12 is used for filtering the direct current component, and the operational amplifying circuit is used for amplifying the voltage after the direct current component is filtered and outputting the voltage to the sample-and-hold circuit.
Further, the sample-and-hold circuit includes an operational amplifier U9D, a diode D1 and a capacitor C1, a non-inverting input terminal of the operational amplifier U9D is connected to one end of a resistor R17 and one end of a resistor R19, the other end of the resistor R17 is connected to an output terminal of the coupling amplifier circuit, the other end of the resistor R19 is grounded, an inverting input terminal of the operational amplifier U9D is connected to one end of a resistor R15 and one end of a resistor R13, the other end of the resistor R15 is grounded, the other end of the resistor R13 is connected to one end of a potentiometer R176, a sliding contact leading-out terminal of the potentiometer R176 is connected to a negative electrode of the diode D1, one end of the capacitor C1 and an input terminal of the bias amplifier circuit, an anode of the diode D1 is connected to an output terminal of the operational amplifier U9D, and the other end of.
Further, the bias amplifying circuit comprises an operational amplifier U9C, a non-inverting input terminal of the operational amplifier U9C is connected with an output terminal of the sample-and-hold circuit, an inverting input terminal of the operational amplifier U9C is connected with one end of a resistor R3 and one end of a resistor R4 respectively, the other end of a resistor R4 is connected with an output terminal of an operational amplifier U9C, the other end of the resistor R3 is connected with a sliding contact leading-out terminal of a potentiometer R174, one end of the potentiometer R174 is connected with one end of a resistor R1, the other end of the resistor R1 is connected with a voltage VDD, the other end of the potentiometer R174 is connected with one end of a resistor R7, the other end of the resistor R7 is grounded, and an output terminal of the operational amplifier U9C is connected with an input terminal.
Further, the transmitting electrode plate and the receiving electrode plate are metal electrode plates, and three-proofing paint is coated on the metal electrode plates or vacuum nano-coating treatment is carried out on the metal electrode plates.
Furthermore, the transmitting electrode plate and the receiving electrode plate are metal electrode plates, and a protective shell is added on the metal electrode plates, so that the metal electrode plates are fully attached to the shell.
Furthermore, the transmitting electrode plate and the receiving electrode plate are both designed by directly laying copper plates on the PCB according to a quadrilateral shape.
Furthermore, the banknote passing channel is positioned between a single pair or multiple pairs of opposite electrode plates, one electrode plate between each pair of opposite electrode plates is a transmitting electrode plate, and the other electrode plate between each pair of opposite electrode plates is a receiving electrode plate.
The utility model also discloses a signal processing circuit of the paper money overlapping detection device, which comprises a coupling amplifying circuit, a sampling holding circuit and an offset amplifying circuit, the input end of the coupling amplifying circuit is electrically connected with the receiving electrode plate, the coupling amplifying circuit is used for filtering direct current components, forming a high-frequency alternating current signal path and amplifying the high-frequency voltage components after the direct current components are filtered, the output end of the coupling amplifying circuit is electrically connected with the input end of the sampling holding circuit, the sampling holding circuit is used for converting the high-frequency coupling component into a direct-current level component, the output end of the sampling and holding circuit is electrically connected with the input end of the bias amplifying circuit, the bias amplifying circuit is used for voltage bias adjustment and continuously amplifying the front-end signal variation, and the output end of the bias amplifying circuit is connected to the microprocessor through the AD conversion circuit.
Further, the coupling amplification circuit comprises a capacitor C12 and an operational amplifier U1, one end of the capacitor C12 is connected with one end of a resistor R7, the other end of the resistor R7 is electrically connected with a receiving electrode plate, the other end of the capacitor C12 is connected with an inverting input end of an operational amplifier U1, an inverting input end of the operational amplifier U1 is connected with one end of the resistor R11, the other end of the resistor R11 is connected with an output end of the operational amplifier U1, a non-inverting input end of the operational amplifier U1 is connected with VDD _ ref, an output end of the operational amplifier U1 is connected with one end of a capacitor C13, and the other end of the capacitor C13 is connected with an input end of the sample and hold;
the sampling and holding circuit comprises an operational amplifier U9D, a diode D1 and a capacitor C1, wherein the non-inverting input end of the operational amplifier U9D is respectively connected with one end of a resistor R17 and one end of a resistor R19, the other end of the resistor R17 is connected with the output end of a coupling amplifying circuit, the other end of the resistor R19 is grounded, the inverting input end of the operational amplifier U9D is respectively connected with one end of a resistor R15 and one end of a resistor R13, the other end of the resistor R15 is grounded, the other end of the resistor R13 is connected with one end of a potentiometer R176, the leading-out end of a sliding contact of the potentiometer R176 is respectively connected with the cathode of the diode D1, one end of the capacitor C1 and the input end of a bias amplifying circuit, the anode of the diode D1 is connected with the output end of the operational amplifier U9D;
the bias amplifying circuit comprises an operational amplifier U9C, wherein the non-inverting input end of the operational amplifier U9C is connected with the output end of a sample hold circuit, the inverting input end of the operational amplifier U9C is connected with one end of a resistor R3 and one end of a resistor R4 respectively, the other end of the resistor R4 is connected with the output end of an operational amplifier U9C, the other end of the resistor R3 is connected with the leading-out end of a sliding contact of a potentiometer R174, one end of the potentiometer R174 is connected with one end of a resistor R1, the other end of the resistor R1 is connected with a voltage VDD, the other end of the potentiometer R174 is connected with one end of a resistor R7, the other end of the resistor R7 is grounded, and the output end of the operational amplifier U9C is connected to a.
The utility model has the advantages that:
when a square wave with a certain frequency is applied to the transmitting polar plate, the receiving polar plate can couple a part of voltage components to the receiving polar plate according to the coupling characteristic of the capacitance polar plate. And (3) according to different capacitance values of different paper money thicknesses between the polar plates, different voltage coupling quantities of different paper money thicknesses exist, and the change of the coupling quantities is detected and compared with a reference value to judge whether the paper money is overlapped or not. This scheme detection device compares ultrasonic wave mode detection device that opens a sheet again, does not need complicated processing circuit such as envelope detection, has the succinct advantage of circuit. Contrast roller bearing transmission, through the mechanical type that detects the extrusion offset measure heavily to open the device, this patent does not need complicated roller bearing mechanical structure, and can single-point arrangement or multiple spot overall arrangement, and simple nimble does not occupy too much structural area, and the cost is lower.
And considering that the influence of the distance between the polar plates on the detection effect is large, the device also comprises a manual or automatic calibration means, detects the reference voltage change of the output signal in real time, and has the function of reference voltage offset adjustment.
The device is flexible and convenient to install, simple in design, capable of being installed in a single point mode, installed in multiple points or installed in an array mode, and capable of achieving the effect of detecting the overlapping.
The device can coat three-proofing paint or carry out vacuum nano coating treatment on the transmitting electrode plate and the receiving electrode plate to play a role in preventing moisture and abrasion, or add a protective shell on the metal electrode plate to ensure that the metal electrode plate is fully attached to the shell, and can also play the role in protecting the electrode plate.
The device can be installed on equipment with related concepts such as a currency counting and detecting machine with a paper currency recognition function, a sorter and the like for use, and is wide in application range and convenient to popularize and use.
Drawings
FIG. 1 is a schematic block diagram of a device for detecting the overlapped paper money according to the present invention;
FIG. 2 is a circuit diagram of a coupling amplifying circuit of the device for detecting the overlapped paper money of the present invention;
FIG. 3 is a circuit diagram of a sample-and-hold circuit and an offset amplifying circuit of the device for detecting the overlapped paper money of the present invention;
FIG. 4 is a schematic view of a single-path distributed banknote feeding passage of the banknote re-sheet detecting device of the present invention;
FIG. 5 is a schematic view of two paths of distributed banknote paths of the banknote re-sheet detecting device of the present invention;
FIG. 6 is a schematic view of the array distribution banknote feeding passage of the banknote re-sheet detecting device of the present invention;
fig. 7 is an illustration of the paper money double-sheet detection device of the utility model for testing the single power ticket and the two power ticket contrast voltage signals.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
Referring to fig. 1 to 6, the embodiment discloses a device for detecting a double-sheet of paper money, which comprises a square wave generator, a signal processing circuit, a microprocessor, an emitting electrode plate and a receiving electrode plate, wherein the emitting electrode plate and the receiving electrode plate are arranged oppositely at intervals, so that a paper money passing channel is formed between the emitting electrode plate and the receiving electrode plate; the square wave generator is electrically connected with the transmitting electrode plate and is used for outputting square wave voltage to the transmitting electrode plate, and when paper money passes through a paper money passing channel between the transmitting electrode plate and the receiving electrode plate, the square wave voltage of the transmitting electrode plate is coupled to the receiving electrode plate; the receiving electrode plate is connected to the microprocessor through the signal processing circuit; the signal processing circuit comprises a coupling amplifying circuit, a sampling holding circuit and a bias amplifying circuit, wherein the input end of the coupling amplifying circuit is electrically connected with the receiving electrode plate, the output end of the coupling amplifying circuit is electrically connected with the input end of the sampling holding circuit, the output end of the sampling holding circuit is electrically connected with the input end of the bias amplifying circuit, and the output end of the bias amplifying circuit is connected to the microprocessor through an AD (analog-to-digital) conversion circuit.
The microprocessor may employ an existing commercially available microprocessor chip. The AD conversion circuit may employ an existing purchased AD chip.
The square wave generator adopts a square wave with a specific frequency and is used for generating an electric field to polarize a dielectric medium between polar plates to form an alternating current coupling voltage path between the polar plates.
And the coupling amplifying circuit is used for filtering the direct current component, forming a high-frequency alternating current signal path and carrying out signal amplification processing.
The sample hold circuit is used for converting the high-frequency coupling component into a direct-current level component, so that signal processing is facilitated.
The bias amplifying circuit is used for adjusting voltage bias, realizes the calibration function by forming adjustable reference voltage bias, and continuously amplifies the variation of the front-end signal.
The coupling amplifying circuit comprises a capacitor C12 and an operational amplifying circuit, wherein the capacitor C12 is used for filtering a direct current component, and the operational amplifying circuit is used for amplifying the voltage after the direct current component is filtered and outputting the voltage to the sampling holding circuit.
The coupling amplifying circuit comprises a capacitor C12 and an operational amplifier U1, one end of the capacitor C12 is connected with one end of a resistor R7, the other end of the resistor R7 is electrically connected with a receiving electrode plate, the other end of the capacitor C12 is connected with an inverting input end of an operational amplifier U1, the inverting input end of the operational amplifier U1 is connected with one end of the resistor R11, the other end of the resistor R11 is connected with an output end of the operational amplifier U1, a non-inverting input end of the operational amplifier U1 is connected with VDD _ ref, an output end of the operational amplifier U1 is connected with one end of a capacitor C13, and the other end of the capacitor C13 is connected with an input end of a sampling. And the power supply pins of the operational amplifiers are respectively connected with a power supply. In the embodiment, 3.3V voltage is adopted to supply power to each operational amplifier.
As shown in fig. 2, TC1 is a receiving electrode plate, a high-frequency square wave signal is transmitted to the receiving electrode plate through the upper and lower electrode plate coupling, so that a certain high-frequency coupling voltage is generated on TC1, then a dc component possibly existing on the receiving electrode plate is filtered out through a coupling amplifying circuit formed by R7, C12, R11 and U1, and the voltage after the dc component is filtered by C12 is subjected to appropriate amplification processing through an operational amplifying circuit and is output to a next-stage processing circuit.
The sample-and-hold circuit is used for enabling the voltage of the first input end of the comparison circuit to increase when the voltage of the output end VOUT _ C1 of the coupled amplification circuit increases, and enabling the voltage of the first input end of the comparison circuit to be kept unchanged when the voltage of the output end VOUT _ C1 of the coupled amplification circuit decreases.
The sampling hold circuit comprises an operational amplifier U9D, a diode D1 and a capacitor C1, wherein the non-inverting input end of the operational amplifier U9D is connected with one end of a resistor R17 and one end of a resistor R19 respectively, the other end of the resistor R17 is connected with the output end of the coupling amplifier circuit, the other end of the resistor R19 is grounded, the inverting input end of the operational amplifier U9D is connected with one end of a resistor R15 and one end of a resistor R13 respectively, the other end of the resistor R15 is grounded, the other end of the resistor R13 is connected with one end of a potentiometer R176, the other end of the potentiometer R176 is not connected, the sliding contact leading-out end of the potentiometer R176 is connected with the negative electrode of the diode D1, one end of the capacitor C1 and one end of the resistor R11 respectively, the positive electrode of the diode D1 is connected with the output end of the operational amplifier U9D, the other end of the capacitor C1 is grounded, and.
When the voltage of the last-stage AC coupling amplification signal VOUT _ C1 increases, the output of the U9D pin14 increases, the diode D1 is conducted, and then the voltage of the U9C pin10 increases by charging the capacitor C1. When the VOUT _ C1 voltage drops, the output of the U9Dpin14 drops, and the diode D1 does not conduct because the voltage on the capacitor C1 does not change abruptly. The U9C pin10 voltage remains unchanged. The sample-and-hold circuit has the capability of detecting the instantaneous voltage jump.
The bias amplifying circuit comprises an operational amplifier U9C, wherein the non-inverting input end of the operational amplifier U9C is connected with the output end of a sample hold circuit, the inverting input end of the operational amplifier U9C is connected with one end of a resistor R3 and one end of a resistor R4 respectively, the other end of the resistor R4 is connected with the output end of an operational amplifier U9C, the other end of the resistor R3 is connected with the leading-out end of a sliding contact of a potentiometer R174, one end of the potentiometer R174 is connected with one end of a resistor R1, the other end of the resistor R1 is connected with a voltage VDD, the other end of the potentiometer R174 is connected with one end of a resistor R7, the other end of the resistor R7 is grounded, and the output end of the operational amplifier U9C is connected to a.
Since the U9C pin10 will acquire a slight voltage variation when the detection means is in operation. The variable quantity needs to be amplified by an amplifying circuit, and then the algorithm characteristic quantity which can be effectively identified by the processor can be obtained.
R1, R174, R7, R3, R4, and U9C constitute a simple amplifier circuit, and can amplify the minute voltage change amount acquired by U9C. In addition, by adjusting the resistance value of the potentiometer R174, the corresponding parameters of the voltage dividing resistor network can be adjusted, and the voltage value of the U9C pin9 is changed, because the value of the output U9C pin8 is obtained by the difference value of the U9C pin10 and the U9C pin9 and then multiplying the difference value by the amplification factor of the amplifying circuit. Therefore, when the reference voltage value of the output U9C pin8 is not ideal, the reference voltage output by the U9C pin8 can be properly adjusted by adjusting the voltage value of the U9C pin9, so that the purpose of adjusting the bias voltage is achieved. And thus does not affect the amplification effect on the small voltage change of U9C PIN10, i.e. the final small voltage change is always equal to Δ V × K.
The transmitting electrode plate 1 and the receiving electrode plate 2 are opposite to each other in a specific distance in physical positions, and an alternating current coupling path is formed by the transmitting electrode plate and the receiving electrode plate when high-frequency square wave voltage is applied. The specific distance between the transmitting electrode plate and the receiving electrode plate is preferably 2-4 mm.
Referring to fig. 4 to 6, the transmitting electrode plate 1 and the receiving electrode plate 2 are respectively positioned above and below the banknote passing machine, the banknote 3 passes through the middle of the banknote passing machine, corresponding signal characteristic changes are reflected after the banknote passing machine passes through the transmitting electrode plate and the receiving electrode plate, the signal characteristic changes are sampled and sent to a processor for operation, and the banknote characteristic state is obtained.
Aiming at the adverse effects of easy abrasion, deterioration, rusting and the like of the metal polar plate exposed in the air, electrostatic damage and the like of the device, the transmitting electrode plate and the receiving electrode plate are provided with protective parts.
Furthermore, the transmitting electrode plate and the receiving electrode plate adopt three-proofing paint or vacuum nano coating treatment, so that the effects of effectively preventing moisture and abrasion caused by paper money friction can be achieved. Because the three-proofing paint or the nano coating are both non-conductive materials, the whole coating can not cause short circuit between the circuit board or the polar plate, which causes the problem of influencing the use.
Furthermore, the transmitting electrode plate and the receiving electrode plate adopt a mode that the shell is attached to the electrode plate, for example, materials such as glass, PVC, ABS, acrylic and the like are firstly designed through the perforated clamping groove, the base plate material is fixed on the banknote passage, and then the electrode plate is fixed on the base plate in an adhesion mode to form an effective whole, so that the purposes of protecting the abrasion of the electrode plate and preventing moisture of the shell are achieved. The thickness of the material of the guard portion is generally recommended not to exceed 0.5 mm. The upper and lower measurement of the cash channel of the machine is designed by the perforated clamping groove, so that the detection sensor is convenient to sink and mount.
According to the structure and the detection precision requirement, the single or multiple opposite polar plates can be adopted to meet the requirement of refolding detection.
The emitting polar plate and the receiving polar plate are both designed by directly laying copper plates on the PCB according to a quadrilateral shape, and the detection circuit can be placed on the corresponding polar plate and also can be placed on other PCBs according to requirements and then is connected through flat cables to achieve the purpose of signal transmission.
The three-proofing paint or the nano coating needs to be uniformly coated on the copper-exposed electrode to achieve the purpose of protecting the metal polar plate.
The metal electrode plates can be fixed on the shell through screws or viscose and the like and are distributed on the upper side and the lower side of the banknote feeding channel of the banknote counting and detecting machine, and the transmitting electrode plates and the receiving electrode plates need to be opposite and vertical to the direction of the banknote feeding channel.
After a specific high-frequency square wave voltage is applied to an emitting electrode plate of the paper money re-opening detection device, when paper money 3 passes through the re-opening detection device, the capacitance of the electrode plate is changed due to the change of dielectric media of an upper electrode plate and a lower electrode plate, so that the amplitude change of the voltage of the emitting electrode plate coupled to a receiving electrode plate is caused, or the voltage component change is called as the coupling voltage component change, and the capacitance change of the electrode plate caused by the dielectric media with different thicknesses is different, so that the coupling voltage component fed back to the receiving electrode plate is also different, and whether the paper money is re-opened or not can be judged by setting a reference value of normal paper money coupling voltage, comparing the actually detected paper money coupling voltage value and combining.
The detection principle of the device is that the voltage variation corresponding to normal single paper money passing through the device is collected and set as a reference value, and when the variation detected by the device exceeds a normal set floating range relative to the reference value, the phenomenon that the paper money is overlapped at the moment is judged. And the device can also realize the sensitivity adjustment of the device by dividing different thresholds.
And the microprocessor decodes and identifies the data transmitted by the AD sampling chip, acquires a voltage value corresponding to the data, and judges whether to perform refolding according to the corresponding voltage coding value.
Any one path of detection effect of the device is selected and explained as follows:
the measured object is a standard 0.1mm paper money practice coupon, and the comparison voltage signals of a single practice coupon and two practice coupons are respectively tested and are shown in figure 7.
The device can be used for realizing single-point installation, multipoint installation or array installation simply, and an application person can evaluate and adopt which layout installation mode according to own design requirements. The device is simple and flexible in structural layout, convenient to install and low in cost, however, the difference of detection ranges can be caused due to different installation quantities, for example, the area which can be detected by multipoint installation is larger as the main difference of the device with single-point installation and multipoint installation, the more the installation quantity is, the higher the detection precision is correspondingly. The utility model discloses detection device has characteristics that the circuit is succinct, simple structure, installation are nimble, with low costs, and applicable in multiple model, can use widely by a large scale.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (10)
1. A paper money double-sheet detection device is characterized in that: the bank note detector comprises a square wave generator, a signal processing circuit, a microprocessor, an emitting electrode plate and a receiving electrode plate, wherein the emitting electrode plate and the receiving electrode plate are arranged oppositely at intervals to form a bank note channel between the emitting electrode plate and the receiving electrode plate; the square wave generator is electrically connected with the transmitting electrode plate and is used for outputting square wave voltage to the transmitting electrode plate, and when paper money passes through a paper money passing channel between the transmitting electrode plate and the receiving electrode plate, the square wave voltage of the transmitting electrode plate is coupled to the receiving electrode plate; the receiving electrode plate is connected to the microprocessor through the signal processing circuit; the signal processing circuit comprises a coupling amplifying circuit, a sampling holding circuit and a bias amplifying circuit, wherein the input end of the coupling amplifying circuit is electrically connected with the receiving electrode plate, the output end of the coupling amplifying circuit is electrically connected with the input end of the sampling holding circuit, the output end of the sampling holding circuit is electrically connected with the input end of the bias amplifying circuit, and the output end of the bias amplifying circuit is connected to the microprocessor through an AD (analog-to-digital) conversion circuit.
2. The banknote multifold detection device according to claim 1, wherein: the coupling amplifying circuit comprises a capacitor C12 and an operational amplifying circuit, wherein the capacitor C12 is used for filtering a direct current component, and the operational amplifying circuit is used for amplifying the voltage after the direct current component is filtered and outputting the voltage to the sampling holding circuit.
3. The banknote multifold detection device according to claim 1, wherein: the sampling and holding circuit comprises an operational amplifier U9D, a diode D1 and a capacitor C1, wherein the non-inverting input end of the operational amplifier U9D is connected with one end of a resistor R17 and one end of a resistor R19 respectively, the other end of the resistor R17 is connected with the output end of the coupling amplifying circuit, the other end of the resistor R19 is grounded, the inverting input end of the operational amplifier U9D is connected with one end of a resistor R15 and one end of a resistor R13 respectively, the other end of the resistor R15 is grounded, the other end of the resistor R13 is connected with one end of a potentiometer R176, the leading-out end of a sliding contact of the potentiometer R176 is connected with the cathode of the diode D1, one end of the capacitor C1 and the input end of the bias amplifying circuit respectively, the anode of the diode D1 is connected with the output end of the operational amplifier U9D.
4. The banknote multifold detection device according to claim 1, wherein: the bias amplifying circuit comprises an operational amplifier U9C, wherein the non-inverting input end of the operational amplifier U9C is connected with the output end of a sampling holding circuit, the inverting input end of the operational amplifier U9C is connected with one end of a resistor R3 and one end of a resistor R4 respectively, the other end of the resistor R4 is connected with the output end of an operational amplifier U9C, the other end of the resistor R3 is connected with the leading-out end of a sliding contact of a potentiometer R174, one end of the potentiometer R174 is connected with one end of a resistor R1, the other end of the resistor R1 is connected with a voltage VDD, the other end of the potentiometer R174 is connected with one end of a resistor R7, the other end of the resistor R7 is grounded, and the output end of the operational amplifier U9C is connected with the.
5. The banknote multifold detection device according to claim 1, wherein: the transmitting electrode plate and the receiving electrode plate adopt metal electrode plates, and the metal electrode plates are coated with three-proofing paint or subjected to vacuum nano-coating treatment.
6. The banknote multifold detection device according to claim 1, wherein: the transmitting electrode plate and the receiving electrode plate are metal electrode plates, and a protective shell is added on the metal electrode plates, so that the metal electrode plates are fully attached to the shell.
7. The banknote multifold detection device according to claim 1, wherein: the transmitting electrode plate and the receiving electrode plate are both designed by directly laying copper plates on the PCB according to a quadrilateral shape.
8. The banknote multifold detection device according to claim 1, wherein: the paper money passage is positioned between a single pair or a plurality of pairs of electrode plates, one electrode plate between each pair of opposite electrode plates is an emitting electrode plate, and the other electrode plate between each pair of opposite electrode plates is a receiving electrode plate.
9. A signal processing circuit of a paper money double-sheet detection device is characterized in that: the input end of the coupling amplifying circuit is electrically connected with a receiving electrode plate, the coupling amplifying circuit is used for filtering a direct current component, forming a high-frequency alternating current signal path and amplifying a high-frequency voltage component after the direct current component is filtered, the output end of the coupling amplifying circuit is electrically connected with the input end of the sampling holding circuit, the sampling holding circuit is used for converting the high-frequency coupling component into a direct current level component, the output end of the sampling holding circuit is electrically connected with the input end of the biasing amplifying circuit, the biasing amplifying circuit is used for voltage bias adjustment and continuously amplifies the front-end signal variation, and the output end of the biasing amplifying circuit is connected to a microprocessor through an AD (analog-to-digital) conversion circuit.
10. The signal processing circuit of a paper money double sheet detection device according to claim 9, characterized in that: the coupling amplifying circuit comprises a capacitor C12 and an operational amplifier U1, one end of the capacitor C12 is connected with one end of a resistor R7, the other end of the resistor R7 is electrically connected with a receiving electrode plate, the other end of the capacitor C12 is connected with the inverting input end of an operational amplifier U1, the inverting input end of the operational amplifier U1 is connected with one end of the resistor R11, the other end of the resistor R11 is connected with the output end of the operational amplifier U1, the non-inverting input end of the operational amplifier U1 is connected with VDD _ ref, the output end of the operational amplifier U1 is connected with one end of a capacitor C13, and the other end of the capacitor C13 is connected with the input end of the sample;
the sampling and holding circuit comprises an operational amplifier U9D, a diode D1 and a capacitor C1, wherein the non-inverting input end of the operational amplifier U9D is respectively connected with one end of a resistor R17 and one end of a resistor R19, the other end of the resistor R17 is connected with the output end of a coupling amplifying circuit, the other end of the resistor R19 is grounded, the inverting input end of the operational amplifier U9D is respectively connected with one end of a resistor R15 and one end of a resistor R13, the other end of the resistor R15 is grounded, the other end of the resistor R13 is connected with one end of a potentiometer R176, the leading-out end of a sliding contact of the potentiometer R176 is respectively connected with the cathode of the diode D1, one end of the capacitor C1 and the input end of a bias amplifying circuit, the anode of the diode D1 is connected with the output end of the operational amplifier U9D;
the bias amplifying circuit comprises an operational amplifier U9C, wherein the non-inverting input end of the operational amplifier U9C is connected with the output end of a sample hold circuit, the inverting input end of the operational amplifier U9C is connected with one end of a resistor R3 and one end of a resistor R4 respectively, the other end of the resistor R4 is connected with the output end of an operational amplifier U9C, the other end of the resistor R3 is connected with the leading-out end of a sliding contact of a potentiometer R174, one end of the potentiometer R174 is connected with one end of a resistor R1, the other end of the resistor R1 is connected with a voltage VDD, the other end of the potentiometer R174 is connected with one end of a resistor R7, the other end of the resistor R7 is grounded, and the output end of the operational amplifier U9C is connected to a.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020478939.XU CN211878649U (en) | 2020-04-03 | 2020-04-03 | Paper money double-sheet detection device and signal processing circuit thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020478939.XU CN211878649U (en) | 2020-04-03 | 2020-04-03 | Paper money double-sheet detection device and signal processing circuit thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211878649U true CN211878649U (en) | 2020-11-06 |
Family
ID=73249993
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020478939.XU Active CN211878649U (en) | 2020-04-03 | 2020-04-03 | Paper money double-sheet detection device and signal processing circuit thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211878649U (en) |
-
2020
- 2020-04-03 CN CN202020478939.XU patent/CN211878649U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100460804C (en) | A capacitive sensor and method for non-contacting gap and dielectric medium measurement | |
| US4255057A (en) | Method for determining quality of U.S. currency | |
| CN105318819B (en) | The detection device of film thickness | |
| CN106091910B (en) | The detection device of film thickness | |
| CN203535713U (en) | Device for ultrasonic detection of tapes and overlapping in banknote processing | |
| CN103925867A (en) | Thickness sensor and thickness measuring method | |
| EP2313763A1 (en) | Input circuit for inductive measurements of the conductivity of a fluid medium | |
| CN101008580A (en) | Resistance type wave height gauge | |
| CN211878649U (en) | Paper money double-sheet detection device and signal processing circuit thereof | |
| CN105606905A (en) | Electromagnetic radiation monitor with weighting function | |
| CN109752416A (en) | Slurry uniformity detection method and application | |
| CN106197248B (en) | The detection device of film thickness | |
| US10240991B2 (en) | Vibration and dynamic acceleration sensing using capacitors | |
| US20170038232A1 (en) | Automatic Calibration Apparatus and Method Thereof | |
| CN205102770U (en) | Detection apparatus for membrane is thick | |
| CN108761368A (en) | Aeolian vibration for transmission line of electricity monitors calibration method | |
| CN205175338U (en) | Thickness check sensor | |
| CN203811121U (en) | Thickness sensor | |
| SE9603379D0 (en) | Device for detecting when a measuring probe comes into contact with a liquid surface | |
| CN114594305A (en) | Differential non-contact voltage sensor | |
| CN104574633A (en) | Ultrasonic detection device and method for adhesive tapes and overlapped paper currency in paper currency treatment | |
| CN209296186U (en) | A kind of pressure distributed detection system | |
| Jančárik et al. | Autonomous sensor of electromagnetic field | |
| CN208888313U (en) | Transient resistance value measuring circuit and high speed hit tester | |
| CN205450122U (en) | Electromagnetic radiation monitor with weighted function |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |