JPH041389B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a detergent liquid detection device for a coin passage of a vending machine that detects when a detergent liquid is injected into a coin passage of a vending machine.

(Prior Art) In conventional vending machines, if water enters from the coin slot through the coin passage and flows into the coin mechanism, it will cause the electric circuit in the coin mechanism to malfunction and the change will flow out. There was a problem.

In order to improve this, a humidity sensor or liquid sensor is installed in the middle of the coin passage.
No. 55-131889), protective measures are taken to prevent malfunction when humidity or liquid is detected.

In addition, a rainwater outlet is provided in the middle of the coin passage to prevent rainwater from flowing into the interior, and the rainwater is allowed to flow out from this rainwater outlet to prevent rainwater from flowing into the coin passageway thereafter.

However, with humidity sensors and liquid sensors,
This poses an impractical problem as the system detects rainwater and stops the vending machine's functions every time rainwater enters the system.

Therefore, recently, vending machines have come into use that use C/MOS/IC in the electric circuit of the coin mechanism to prevent malfunctions when exposed to natural water such as rainwater.

(Problem to be Solved by the Invention) However, even in the vending machine using the C/MOS/IC mentioned above, if kitchen household detergent is sprayed into the coin slot and poured into the coin mechanism from the coin passage, Since the impedance of the detergent liquid is lower than that of water, the electric circuit within the coin mechanism malfunctions, resulting in theft accidents in which the detergent liquid is injected and change flows out, and the change is stolen.

An object of the present invention is to provide a detergent liquid detection device for a coin passage of a vending machine that can detect that a detergent liquid is injected into a coin passage.

(Means for Solving the Problems) To explain the configuration of the present invention for achieving the above object, the device for detecting the injection of detergent liquid into the coin slot of the present invention consists of opposing electrodes, and is arranged in the coin passage. a sensor circuit consisting of a voltage dividing circuit including a detergent liquid sensor and a resistor connected in series with the detergent liquid sensor; a detection reference voltage forming circuit comprising a voltage dividing circuit in which a plurality of resistors are connected in series; The detection voltage from the detection reference voltage forming circuit is used as one input, and the detection reference voltage from the detection reference voltage forming circuit is used as the other input for comparison. a ripple compensation type detection circuit that operates to output an output voltage that is inversely proportional to the resistance value of the detergent liquid sensor and to relatively lower the detection reference voltage by a ripple compensation voltage when the detection reference voltage increases; a detergent liquid determination circuit that measures the duration of the output of the ripple compensation type detection circuit and determines that the detergent liquid has been injected when the output continues for a predetermined time or more, and the counter electrode is ,
They are characterized by being made of a conductive material that does not dissolve into the natural water when immersed in natural water such as rainwater and energized.

(Function) In this invention, when water exists between the opposing electrodes to which a DC voltage is applied, the resistance value between the two electrodes increases due to the electrolysis of water between the two electrodes, whereas the resistance value between the two electrodes increases. This was done by focusing on the phenomenon that the resistance value between both electrodes decreases.

Therefore, when detergent liquid is present in this detergent liquid sensor, the resistance value between both electrodes of the sensor decreases after a predetermined period of time, and the detection voltage of the sensor circuit increases and exceeds the detection reference voltage. The detection circuit continuously outputs an output that is inversely proportional to the resistance value of the detergent liquid sensor. As a result, the determination output is continuously output from the detergent liquid determination circuit, so that it is known that the detergent has been injected.

On the other hand, when water is present in the detergent liquid sensor, the resistance value between both electrodes of the sensor increases after a predetermined time due to water electrolysis, the detection voltage of the sensor circuit decreases, and the detection reference voltage decreases after 1 to 2 seconds. Since the voltage is no longer reached, the ripple compensation type detection circuit no longer outputs an output. Therefore, even if the ripple compensation type detection circuit initially outputs an output in the detergent liquid determination circuit,
Since the output disappears after 1 to 2 seconds, no judgment output is output.

In the ripple compensation type detection circuit, when the detection voltage exceeds the detection reference voltage and outputs, the detection reference voltage is relatively lowered by the ripple compensation voltage.
Immediately after that, even if a ripple occurs in which the detection voltage drops or rises from the initial detection reference voltage value, the output will not be stopped or output, but will continue to be output, preventing chattering and stabilizing the operation. can.

In addition, if the detergent solution sensor is made of materials such as copper, gold, or silver, if the counter electrode is immersed in water for a long time, the water becomes an electrolyte and the electrode material is eluted, causing the resistance to drop again. However, by using a conductive material such as stainless steel, zirconium, or other ceramic for the counter electrode that does not elute even when immersed in water and energized, it is possible to avoid immersion in water for a long time. The detection voltage does not reach the reference voltage even if the

(Example) Hereinafter, an example of the present invention will be described in detail with reference to FIGS. 1 to 3. As shown in the figure, a coin slot 2 is provided on the front side of the vending machine 1. On the back side of this coin slot 2, there are a first and a second coin slot.
A coin passage 5 is formed by the chute 3 and 4, and coins passing through the coin passage 5 are thrown into a coin mechanism 6. A prevention plate 7 is suspended immediately after the coin slot 2 to prevent rainwater from entering the coin passage 5 and to allow it to fall from the drop opening 8 below into the drainage passage 9 and be drained. There is. Furthermore, a guide plate 10 is provided at the lower end of the first chute 3 at the boundary between the first and second sheets 3 and 4 to guide the liquid toward the drain passage 9 side. Note that 11 is a signboard, and 12 is a lighting lamp that illuminates the signboard 11.

Detergent liquid sensors 13 are disposed at a plurality of locations at the bottom of the coin passage 5. As shown in FIG. 3, the detergent liquid sensor 13 is held on an insulating substrate 40 and includes a pair of opposing electrodes 13A and 13B that are placed opposite each other at a predetermined interval. These electrodes 13A, 13B are both formed of stainless steel plates, and the lead wire connection terminal portions 41A,
Lead wires 42, 42 are passed through 41B, and solder 4
3,43. The outer surface of the solder portion is coated with an insulating paint 44.

The materials used for both electrodes 13A and 13B are:
When both electrodes are immersed in natural water such as rainwater and energized, the water becomes an electrolytic solution, and the electrode material is made of a conductive material that does not dissolve into the water. Specific examples include zirconium, conductive ceramic, and the like, in addition to the above-mentioned stainless steel.

The electrodes 13A and 13B of the detergent liquid sensor 13 configured in this manner are connected to a sensor circuit 16 consisting of a voltage dividing circuit connected in series with a resistor 14 and a variable resistor 15.
is incorporated within. One end of the resistor 14 of the sensor circuit 16 is connected to the positive side of a series power supply (not shown), and the other end of the variable resistor 15 is grounded. Capacitor 1 is connected to variable resistor 15.
7 are connected in parallel. The detected voltage of the sensor circuit 16 appears as a divided voltage across the variable resistor 15, and this detected voltage passes through the resistor 18 and is connected to C.
It is applied to the positive input terminal of a ripple compensation type detection circuit 19 consisting of a MOS/IC comparator. On the input side of the ripple compensation type detection circuit 19, a detection reference voltage forming circuit 22 is further provided, which is a voltage dividing circuit in which resistors 20 and 21 are connected in series. One end of the resistor 20 of the detection reference voltage forming circuit 22 is connected to the plus side of the aforementioned DC power supply (not shown), and the other end of the resistor 21 is grounded. The detection reference voltage of the detection reference voltage forming circuit 22 is applied to the resistor 21 as a divided voltage.
This detection reference voltage is applied to the negative input terminal of the ripple compensation type detection circuit 19. This detection reference voltage is determined to have a value equal to the detection voltage for the resistance value of the detergent liquid.

A ripple compensation resistor 23 is connected between the output terminal and the positive input terminal of the ripple compensation type detection circuit 19, which operates to relatively lower the detected voltage by the ripple compensation voltage immediately after detecting the detergent liquid. There is. Furthermore, a sensitivity adjustment resistor 24 is connected between the output terminal and the negative input terminal of the ripple compensation type detection circuit 19.

The output terminal of the ripple compensation type detection circuit 19 measures the duration of the output, and when the output lasts for a predetermined time or more, continuously outputs an output voltage inversely proportional to the resistance value of the detergent liquid. A first detergent liquid determination circuit 25 that determines that liquid has been injected is connected. The first detergent liquid determination circuit 25 is formed of an integrating circuit including a resistor 26 and a capacitor 27.

The output voltage of this first detergent liquid determination circuit 25 is
The signal is input via a resistor 28 to the positive input terminal of a ripple-compensated second detergent liquid determination circuit 29 made up of a C/MOS/IC comparator. Ripple compensation type second detergent liquid determination circuit 29
A determination reference voltage forming circuit 32 consisting of a voltage dividing circuit in which resistors 30 and 31 are connected in series is provided on the input side. One end of the resistor 30 of the judgment reference voltage forming circuit 32 is connected to the positive side of a DC power supply (not described above), and the other end of the resistor 31 is grounded. The determination reference voltage of the determination reference voltage forming circuit 32 appears as a divided voltage across the resistor 31, and this determination reference voltage is applied to the negative input terminal of the ripple compensation type second detergent liquid determination circuit 29. It's summery. This determination reference voltage is determined to have a value equal to the detection voltage for the resistance value of the detergent liquid.

There is an operation between the output terminal and the positive input terminal of the ripple compensation type second detergent liquid determination circuit 29 to relatively lower the determination reference voltage by the ripple compensation voltage immediately after determination of the detergent liquid in this circuit. A ripple compensation resistor 33 is connected to perform this. Further, a sensitivity adjustment resistor 3 is connected between the output terminal and the negative input terminal of the second detergent liquid determination circuit 29 of the ripple compensation type.
4 is connected.

A switching transistor 37 is connected to the output terminal of the ripple compensation type second detergent liquid determination circuit 29 via resistors 35 and 36, and a switching transistor 37 is connected to the collector side of the switching transistor 37. A controlled buzzer 38 is connected.

In such a detergent liquid injection detection device, when detergent liquid is injected into the coin slot 2 and passes through the coin passage 5 and reaches the detergent liquid sensor 13, the resistance value between the electrodes 13A and 13B of the detergent liquid sensor 13 is determined by the detergent liquid. When the liquid first entered, the resistance was 10KΩ, but after 1 to 2 seconds it became
It drops to about 5KΩ. Therefore, at the input of the ripple compensation type detection circuit 19, the detection voltage is initially smaller than the detection reference voltage, and the output of the ripple compensation type detection circuit 22 is 0. Next, when the resistance value of the detergent liquid sensor 13 decreases after a predetermined period of time, the voltage division ratio changes and the detection voltage becomes larger than the detection reference voltage, and an output corresponding to the increase occurs from the ripple compensation type detection circuit 19. This output increases in inverse proportion to the decrease in the resistance value of the detergent liquid sensor 13. When the ripple compensation type detection circuit 19 outputs an output in this way, the detection reference voltage is relatively lowered by the ripple compensation voltage determined by the resistance value of the ripple compensation resistor 23. Therefore, even if the detection voltage decreases and then increases immediately after that, the detection reference voltage remains at a voltage lower than that, so the ripple compensation type detection circuit 19 continues to output and prevents the subsequent circuit from chattering. do. The output of the ripple compensation type determination circuit 19 is given to a first detergent liquid determination circuit 25, and the duration of the output is measured using a capacitor 27. When detergent liquid is present in the detergent liquid sensor 13,
Since the input continues to be applied to the first detergent liquid determination circuit 25, the charging voltage of the capacitor 27 increases, and the first determination output at a predetermined level indicating that the detergent liquid is being supplied is output. This first judgment output is sent to the ripple compensation type second detergent liquid judgment circuit 29.
A board-specific reference voltage is applied from the judgment reference voltage forming circuit 32 to the negative input terminal. In this case, since the first judgment output exceeds the judgment reference voltage, the second judgment output appears from the ripple compensation type second detergent liquid judgment circuit 29 by the amount exceeding the judgment reference voltage. This second judgment output increases in inverse proportion to the decrease in the resistance value of the detergent liquid sensor 13. This second judgment output turns on the switching transistor 37, and the buzzer 38 starts sounding to notify that the detergent liquid has been injected. Further, it is also possible to operate a relay using the switching transistor 37 to stop coins from flowing out.

Note that such an operation also occurs when saline is injected into the coin slot 2, and the buzzer 38 can be sounded.

On the other hand, when water is injected into the coin slot 2, the resistance value of the detergent liquid sensor 13 was initially about 10KΩ due to the water injection, but due to the electrolysis of the water, the surfaces of the electrodes 13A and 13B are insulated. After 1-2 seconds, it increases to 50KΩ to 150KΩ. Therefore, even if the ripple compensation type detection circuit 19 momentarily outputs an output at first, it immediately stops outputting. This instantaneous output is absorbed by the first detergent liquid determination circuit 25, and the buzzer 38 does not sound.

Even if an erroneous determination is output from the first detergent liquid determination circuit 25 for some reason, the second detergent liquid determination circuit 29
Since the re-judgment is carried out, erroneous determination can be prevented.

An experiment was conducted to determine the resistance change when a stainless steel plate was used for the electrode of the detergent liquid sensor and when solder plating was used for the electrode, and the results were as shown in the graph shown in FIG. In the graph, detergent, cola,
, shows the results of experiments on tap water, well water, and rainwater, and , solder plating was used as the electrode material, and stainless steel plates were used for the other electrode materials. In addition, the circuit shown in FIG. 5 was used in the experiment.

(Effects of the Invention) As explained above, in the present invention, the detergent liquid has a characteristic that the resistance value decreases when a voltage is applied between the electrodes, and this is detected by the ripple compensation type determination circuit. Since the detergent liquid determination circuit determines whether the detection is correct using the duration of the output, it is possible to correctly detect that the detergent liquid has been injected. Therefore, theft of coins from vending machines can be prevented.
Furthermore, in the device of the present invention, a ripple compensation type detection circuit is used to relatively lower the detection reference voltage by the ripple compensation voltage after detection, so even if the detection voltage drops or rises immediately thereafter, this is ignored. This stabilizes the output and prevents chattering in subsequent circuits.

Furthermore, the counter electrodes constituting the detergent liquid sensor of the present invention are made of a conductive material that does not dissolve into natural water when immersed in rainwater or other natural water and energized. Even if the device is immersed in water for a long time, the resistance value between both electrodes does not decrease, so the detection voltage does not reach the reference voltage, and malfunctions due to the material of the counter electrode can be prevented.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a detergent liquid detection device for a coin passage in a vending machine according to the present invention, FIG. The figure is a perspective view of the detergent liquid sensor, Figure 4 is a graph showing the experimental results, and Figure 5 is the circuit used in the experiment. 1...Vending machine, 2...Coin slot, 5...
...Coin passage, 13...Detergent liquid sensor, 13
A, 13B... Electrode, 14... Resistor, 15... Variable resistor, 16... Sensor circuit, 19... Ripple compensation detection circuit, 20, 21... Resistor, 22...
Detection reference voltage forming circuit, 23... Ripple compensation resistor, 25... First detergent liquid determination circuit, 26... Resistor, 27... Capacitor, 29... Second detergent liquid determination circuit, 32... Judgment standard Voltage forming circuit, 37
...Switching transistor, 38...Buzzer.

Claims (1)

[Claims] 1 A sensor circuit consisting of a voltage dividing circuit consisting of a detergent liquid sensor arranged in a coin passageway with opposing electrodes and a resistor connected in series with the detergent liquid sensor, and a voltage dividing circuit comprising a plurality of resistors connected in series. A comparison is made with the detection voltage from the detection reference voltage forming circuit and the sensor circuit as one input, and the detection reference voltage from the detection reference voltage forming circuit as the other input, and a voltage is generated between the opposing electrodes of the detergent liquid sensor. When detergent liquid is present and the detection voltage rises above the detection reference voltage, an output voltage that is inversely proportional to the resistance value of the detergent liquid sensor is output, and the detection reference voltage is relatively lowered by a ripple compensation voltage. Measuring the operating ripple compensation type detection circuit and the duration of the output of the ripple compensation type detection circuit, and when the output continues for a predetermined time or more,
a detergent liquid determination circuit that determines that the detergent liquid has been injected, and the counter electrode is made of a conductive material that does not dissolve into natural water such as rainwater when immersed in natural water such as rainwater and energized. A detergent liquid detection device for the coin passage of a vending machine consisting of: