Patent Application
20140260602
1. Technical Field
The present disclosure relates to water-level detecting systems, and more particularly to a water-level detecting system and a water-level detecting method for a vending machine.
2. Description of Related Art
Vending machines often comprise a cooling system for absorbing heat generated by the vending machine. In addition, the vending machine further comprises a water receiving device for receiving water condensate generated by the cooling system. However, the water may spill out of the water receiving device and damage the vending machine. Therefore, there is room for improvement within the art.
Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments. Moreover, in the drawings, like-reference numerals designate corresponding parts throughout the several views.
The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean “at least one.”
The signal generating module 10 comprises a time-base circuit 11, a first capacitor C1, a second capacitor C2, a third capacitor C3, and a diode D1. The time-base circuit 11 comprises a ground pin 1, a low trigger pin 2, an output pin 3, a high trigger pin 6, a discharge pin 7, and a power supply pin 8. The ground pin 1 is connected to a power supply Vcc via the first capacitor C1. The low trigger pin 2 is ground via the second capacitor C2. The output pin 3 is connected to the third capacitor C3, and the third capacitor C3 is connected to the detecting module 20 through a resistor R3. The high trigger pin 6 and the low trigger pin 2 are connected to a node 12. The discharge pin 7 is connected to the power supply Vcc via a resistor R1 and is connected to the node 12 via a resistor R2. An anode of the diode D1 is connected to the discharge pin 7, and a cathode of the diode D1 is connected to the node 12. The power supply pin 8 is connected to the power supply Vcc. In one embodiment, a capacitance of the first capacitor C1 is about 0.1 microfarad (μF), a capacitance of the second capacitor C2 is about 10 μF, a resistance of the resistor R1 is about 6.8 KΩ and is substantially equal to a resistance of the resistor R2, and a resistance of the resistor R3 is about 3.3 KΩ.
The detecting module 20 comprises a frequency-to-voltage converter 21, a varicap 22, a first sliding rheostat 23, a second sliding rheostat 24, a third sliding rheostat 25, and a displaying meter 26. A pin TACH+ of the frequency-to-voltage converter 21 is connected to the resistor R3. A pin CAP1 of the frequency-to-voltage converter 21 is connected to a node 270 via a capacitor C4, and the node 270 is connected to a sliding terminal of the first sliding rheostat 23 via a resistor R4. Two connecting terminals of the first sliding rheostat 23 are connected to the power supply Vcc and grounded, respectively. A pin CPO of the frequency-to-voltage converter 21 is grounded via a resistor R5. A pin IN+ of the frequency-to-voltage converter 21 is grounded via a fifth capacitor C5 and is further connected to the pin CPO of the frequency-to-voltage converter 21. A pin E of the frequency-to-voltage converter 21 is grounded via a resistor R11 and is further connected to a node 271. A pin VCC and a pin C of the frequency-to-voltage converter 21 are connected to the power supply Vcc. A pin IN− of the frequency-to-voltage converter 21 is connected to the node 271. A pin TACH− and a pin GND of the frequency-to-voltage converter 21 are grounded.
A sliding terminal of the second sliding rheostat 24 and a first connecting terminal of the second sliding rheostat 24 are connected to the node 271. A second connecting terminal of the second sliding rheostat 24 is connected to a resistor R6, and the resistor R6 is grounded via the displaying meter 26. A first connecting terminal of the third sliding rheostat 25 is connected to the node 271, and a second connecting terminal of the third sliding rheostat 25 is grounded. A sliding terminal of the third sliding rheostat 25 is connected to the comparing module 30. In one embodiment, a resistance of the resistor R4 is about 470 KΩ, a resistance of the resistor R5 is about 100 MΩ, a resistance of the resistor R6 is about 4.7 KΩ, a capacitance of the fourth capacitor C4 is about 1 μF, and a capacitance of the second capacitor C5 is about 1 μF.
The comparing module 30 comprises a fourth sliding rheostat 31 and an operational amplifier 32. A first connecting terminal of the fourth sliding rheostat 31 is connected to the power supply Vcc, and a second connecting terminal of the fourth sliding rheostat 31 is grounded. A sliding terminal of the fourth sliding rheostat 31 is connected to a negative terminal of the operational amplifier 32. A positive terminal of the operational amplifier 32 is connected to the sliding terminal of the fourth sliding rheostat 31 via a resistor R8. The operational amplifier 32 is also connected to a node 33, and the node 33 is connected to the power supply Vcc via a resistor R9. In one embodiment, a resistance of the resistor R7 is 4.7KΩ, a resistance of the resistor R8 is 4.7 KΩ, and a resistance of the resistor R9 is 1KΩ.
The indicator module 40 comprises an indicator light 41. The node 33 is connected to a resistor R10, and the resistor R10 is grounded via the indicator light 41. In one embodiment, a resistance of the resistor R10 is 470Ω.
The water receiving module 50 comprises a water tank 51, a floating block 52 floating on water of the water tank 51, and a connecting portion 53 connected to the floating block 52. The connecting portion 53 is connected to the sliding terminal of the first sliding rheostat 23.
In use, a water level of the water of the water tank 51 rises up or down and consequently moves the floating block 52 up or down, so that the connecting portion 53 moves the sliding terminal of the first sliding rheostat 23 to change a voltage of the varicap 22. Simultaneously, a frequency value fe is inputted to the detecting module 20 by the time-base circuit 11. A voltage Ue is outputted by the frequency-to-voltage converter 21 and the voltage Ue is obtained by the formula Ue=f*R*U*Cx, where f is the frequency value fe, R is the resistance of the resistor R3, U is the operating voltage of the water-level detecting system, and Cx is the capacitance of the pin CAP1 of the frequency-to-voltage converter 21. Cx is the total capacitance of the capacitor C4 and the varicap 22. Thus, Ue is determined by the capacitance of the varicap 22, and the capacitance can be obtained by the varicap 22 according to the water level of the water in the water tank 51. In one embodiment, the water level of the water in the water tank 51 is displayed by the displaying meter 26. The operational amplifier 32 compares the Ue with a predetermined voltage Up. When the water level of the water in the water tank 51 is greater than a predetermined water level and the Ue is greater than the predetermined voltage Up, the indicator light 41 lights up. When the water level of the water in the water tank 51 is normal and the Ue is less than the predetermined voltage Up, the indicator light 41 does not light up.
S1: locating a water receiving module 50 in the vending mechanism.
S2: moving the floating block by rising water in the water tank 51 to slide a sliding terminal of the first sliding rheostat 23.
S3: changing a capacitance of the varicap 22, when the sliding terminal of the first sliding rheostat 23 is slid.
S4: changing a voltage of the frequency-to-voltage converter 21 according to the capacitance of the varicap 22.
S5: comparing the voltage of the frequency-to-voltage converter 21 with a predetermined voltage by the comparing module 30.
S6: lighting an indicator module 40 when the voltage of the frequency-to-voltage converter is greater than the predetermined voltage.
It is to be understood, however, that even though numerous characteristics and advantages have been set forth in the foregoing description of embodiments, together with details of the structures and functions of the embodiments, the disclosure is illustrative only and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013100852435 | Mar 2013 | CN | national |
