Patent Publication Number: US-2011074334-A1

Title: Power-saving solar power supply system for automatic vending machine

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a power supply system for an automatic vending machine and more particularly, to a power-saving solar power supply system for automatic vending machine, which provides the necessary working power to the recognition system of the automatic vending machine when the recognition system is in the idle mode so that the automatic vending machine does not need to start up its power supply system during the idle mode, saving power consumption. 
     2. Description of the Related Art 
     Following fast progress of social civilization and fast development of modern technology, the pace of life has been accelerating, and people in city are busy. In consequence, automatic vending machines are intensively used and installed in public places to sell different products or to provide different services, bringing convenience to people and saving much the labor cost. 
     Regular automatic vending machines are used to sell different products 24 hours a day without serviceman. These automatic vending machines are highly invited for the advantage of saving much labor and bringing convenience to people. However, an automatic vending machine consumes much power supply when started up. To save power consumption, an automatic vending machine may provide an idle mode. An automatic vending machine with a power-saving idle mode reduces the consumption of power of its motor drive and recognition system. Normally, an automatic vending machine with a power-saving idle mode can save power consumption about 34%. Many countries have established regulations to rule power consumption. European Union defines a EuP&#39;s ecological profile that consists of the measurable physical inputs and outputs (such as materials, emissions and waste) over the product&#39;s entire life cycle. The EuP directive provides the legislative criteria and framework for the move to life cycle ecodesign. 
     There are automatic vending machine providers install a power management unit in each automatic vending machine they provide. The power management unit provides power management or switches the automatic vending machine to an idle mode or off mode when the main function of the automatic vending machine is not started or the recognition system of the automatic vending machine does to provide its service, thereby saving power consumption. During the idle mode, the power consumption is below 0.5 W. The internal rechargeable battery of the automatic vending machine can satisfy the power consumption when the recognition system is in the idle mode. However, the power of a battery used in an automatic vending machine will be used up within a certain length of time. The automatic vending machine business operator must send people to check the power level of the battery of each installed automatic vending machine regularly and to replace the battery of which the power is low. This automatic vending machine business operating manner greatly increases the labor cost. 
     Therefore, it is desirable to provide a green power supply system that is practical for use in any of a variety of existing automatic vending machines, saving the consumption of power. 
     SUMMARY OF THE INVENTION 
     The present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a power-saving solar power supply system for automatic vending machine, which saves power consumption and assures normal functioning of the automatic vending machine. 
     To achieve this and other objects of the present invention, a power-saving solar power supply system for automatic vending machine comprises a power supply module having a solar cell set and a rechargeable battery set, and a power management unit. The power management unit comprises a microprocessor, a voltage detection device controllable by the microprocessor to detect the voltage level of the solar cell set and the rechargeable battery set, a power switching module controllable by the microprocessor to alternatively switch between the solar cell set and the rechargeable battery set subject to the detection result of the voltage detection device, an idle power supply module electrically connected to the recognition system of the automatic vending machine and controllable by the microprocessor through the power switching module to provide battery power supply from one the solar cell set and the rechargeable battery set to the recognition system subject to the detection result of the voltage detection device, a sleep/wakeup switch controllable by the microprocessor to switch the idle power supply module between a sleep mode and a wakeup mode, and a charging control module controllable by the microprocessor to charge the rechargeable battery set with the solar cell set. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a system block diagram of a power-saving solar power supply system for automatic vending machine in accordance with the present invention. 
         FIG. 2  is a sleep/wakeup operation flow chart of the present invention. 
         FIG. 3  is a power switching flow chart of the present invention. 
         FIG. 4  is schematic drawing showing the outer appearance of an automatic vending machine equipped with a power-saving solar power supply system in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1˜4 , a power-saving solar power supply system for automatic vending machine in accordance with the present invention is shown installed in an automatic vending machine  3 , comprising a power supply module  1  and a power management unit  2 . 
     The power supply module  1  comprises a solar cell set  11  and a rechargeable battery set  12 . The solar cell set  11  comprises a plurality of solar cells arranged in an array. The solar cells can be solar cell lamps or solar cell SMDs (Surface Mounted Devices). One single piece of solar cell lamp provides 0.95V, 4 mA. One single piece of solar cell SMD provides 0.95V, 10 mA. 
     The power management unit  2  comprises a microprocessor  21 , a voltage detection device  22  electrically connected to the microprocessor  21  and adapted to detect the voltage of the solar cell set  11  and the rechargeable battery set  12 , a power switching module  23 , which is electrically connected to the solar cell set  11  and the rechargeable battery set  12  and controllable by the microprocessor  21  to alternatively switch between the solar cell set  11  and the rechargeable battery set  12 , an idle power supply module  24 , which is electrically connected to the recognition system  32  of the automatic vending machine  3  and controllable by the microprocessor  21  through the power switching module  23  to provide battery power supply from the solar cell set  11  or the rechargeable battery set  12  to the recognition system  32  of the automatic vending machine  3 , a sleep/wakeup switch  25  electrically connected to the idle power supply module  24  and controllable by the microprocessor  21  to switch the idle power supply module  24  between a sleep mode and a wakeup mode, a charging control module  26 , which comprises a buck-boost converter  261  electrically connected in series between the solar cell set  11  and the rechargeable battery set  12  and controllable by the microprocessor  21  to raise or lower the voltage of the output power of the solar cell set  11  for charging the rechargeable battery set  12 , and a message indicator light module  27  that comprises a digital/analog converter  271  electrically connected to the microprocessor  21  and controllable by the microprocessor  21  to provide different visual indications. 
     The automatic vending machine  3  comprises a housing  31  and a recognition system  32  mounted in the housing  31  and electrically connected to the microprocessor  21  of the power management unit  2 . The housing  31  has a motor drive (not shown) mounted therein, a face panel  311  located on the front side, multiple merchandise exhibition compartments  312  defined in the face panel  311  at different elevations, a plurality of buttons  313  arranged on the face panel  311  corresponding to the merchandise exhibition compartments  312 , and a merchandise takeout outlet  314  formed in the face panel  311  near the bottom side. The recognition system  32  comprises a card-sliding unit  321 , a bill acceptor  322 , a license recognition unit  323  and a coin slot unit  324  respectively exposed to the outside of the face panel  311 . When a user wishes to purchase merchandise from the automatic vending machine  3 , the user must insert a license into the card-sliding unit  321  or the license recognition unit  323  for recognition. The user can insert a bill into the bill acceptor  322  or a coin into the coin slot unit  324  only after his (her) license has been recognized and approved. After receipt of a bill or coin, the microprocessor  21  drives the motor drive in the housing  31  to dispense the selected age-controlled merchandise to the merchandise takeout outlet  314 , finishing the transaction. Thus, the automatic vending machine  3  can sell controlled merchandise and can prohibit unqualified people to purchase controlled merchandise. 
     When starting up the recognition function, the system runs subject to the following steps:
     (101) Start up initialization;   (102) Run auto check, and then proceed to step (103) when error, or step (105) when normal;   (103) Display error message;   (104) Enter sleep mode;   (105) Enter idle mode and simultaneously detect any insertion of a bill, coin, credit card or license within a predetermined time period, and then repeat step (104) when negative, or proceed to step (106) when positive;   (106) Enter wakeup mode;   (107) Determine whether a bill or a credit card/license is inserted, and then proceed to step (108) when a credit card/license is inserted, or step (112) when a bill is inserted;   (108) Recognize the inserted credit card/license is a genuine card or license, and then proceed to step (109) if the credit card/license is a counterfeit card or counterfeit license, or step (110) if the credit card/license is a genuine card or genuine license;   (109) Display the message of invalid card/license, and then return to step (105);   (110) Provide a recognition result signal to the microprocessor  21  and eject the inserted credit card/license;   (111) Wait for instruction from the microprocessor  21  whether or not to accept the recognition result, and then return to step (105) when negative, or proceed to step (112) when positive;   (112) Recognize the authenticity and face value of the inserted bill, and then return to step (105) if the inserted bill is a counterfeit, or proceed to step (113) if the bill is a genuine bill;   (113) Send a recognition result signal to the microprocessor  21  and then return to step (105).   

     As stated above, after startup of the automatic vending machine  3 , the microprocessor  21  runs initialization to set firmware parameters and to check any error automatically. When an error is found, the microprocessor  21  controls the message indicator light module  27  to give a corresponding visual indication by means of turning on a corresponding color light or flashing one light subject to a predetermined frequency. At the same time, the microprocessor  21  controls the sleep/wakeup switch  25  to switch the recognition system  32  to the sleep mode. When normal, the recognition system  32  enters the idle mode, and the microprocessor  21  controls the power switching module  23  to switch to the solar cell set  11  or the rechargeable battery set  12  subject to voltage detection result and to further provide power supply to the recognition system  32  via the idle power supply module  24 . During the idle mode, the recognition system  32  detects any insertion of a bill, coin, credit card or license within a predetermined time period, and then enters the sleep mode after a predetermined time period when no any insertion is detected. When an insertion is detected, the user must insert a credit card or license into the card-sliding unit  321  or the license recognition unit  323  at first. After the inserted credit card or license has passed the verification and has been rejected, it is necessary to wait for the decision of the microprocessor  21  whether or not to accept the recognition result. When the microprocessor  21  accepts the recognition result, the automatic vending machine  3  immediately enters the wakeup mode, thereby turning on the power supply for the bill acceptor  322  and the coin slot unit  324  for the insertion of a bill or coin. When a bill is inserted into the bill acceptor  322 , the bill acceptor recognizes the authenticity and value of the inserted bill. If the inserted bill or coin is a counterfeit, the microprocessor  21  controls the message indicator light module  27  to give a visual signal indicative of an invalid message and then drives the recognition system  32  into the sleep mode. Therefore, when the automatic vending machine  3  is in the idle mode, the power supply is not started up to run merchandise selling operation. At this time, the idle power supply module  24  provides the necessary working voltage to the recognition system  32  to scan any insertion of a bill, coin, credit card or license. By means of the solar cell set  11  or rechargeable battery set  1  of the solar cell power supply module  1 , the recognition system  32  can obtain sufficient power supply required during its idle mode, saving power consumption for the motor drive, lighting fixture and peripheral devices of the recognition system  32 . Therefore, the invention effectively saves power consumption, and reduces management cost. 
     Further, when entering the idle mode, the power supply switching operation runs subject to the following steps (as shown in  FIG. 3 ):
     (201) Start up;   (202) Detect whether or not the voltage of the solar cell set  11  is over a predetermined reference voltage value? And then proceed to step (203) when over the predetermined reference voltage value, or step (204) when below the predetermined reference voltage value;   (203) Switch to the solar cell set  11  to obtain the necessary working voltage from the solar cell set  11  to let the rechargeable battery set  12  to be charged with the power supply from the solar cell set  11 , and then return to step (202);   (204) Switch to the rechargeable battery set  12  to obtain the necessary working voltage from the rechargeable battery set  12 , and then return to step (202).   

     It is to be understood that when the power supply module  1  and the power management unit  2  are started up, the voltage detection device  22  detects the voltage level of the solar cell set  11  and compared the detected voltage to a predetermined reference voltage value. The microprocessor  21  decides whether or nor to let the solar cell set  11  output its power supply subject to the detection result from the voltage detection device  22 . If the voltage of the solar cell set  11  surpasses the predetermined reference voltage value, the microprocessor  21  gives a signal to the power switching module  23 , causing the power switching module  23  to switch on the connection between the solar cell set  11  and the idle power supply module  24  and to simultaneously switch off the connection between the rechargeable battery set  12  and the idle power supply module  24 , enabling the power supply to be supplied from the solar cell set  11  to the sleep/wakeup switch  25 , the microprocessor  21  and the recognition system  32  of the automatic vending machine  3 . At this time, the microprocessor  21  gives a signal to the charging control module  26 , causing the charging control module  26  to charge the rechargeable battery set  12  with the solar cell set  11 . If the voltage of the solar cell set  11  is below the predetermined reference voltage value, the power switching module  23  switches off the connection between the solar cell set  11  and the idle power supply module  24  and simultaneously switch on the connection between the rechargeable battery set  12  and the idle power supply module  24 , enabling the power supply to be supplied from the rechargeable battery set  12  to the sleep/wakeup switch  25 , the microprocessor  21  and the recognition system  32  of the automatic vending machine  3 . Further, it the vending machine  3  has a rechargeable power supply unit set therein, the aforesaid rechargeable battery set can be eliminated. In this case, the rechargeable power supply unit of the automatic vending machine  3  is electrically connected to the power switching module  23  and voltage detection device  22  of the power management unit  2 , i.e., the rechargeable power supply unit of the automatic vending machine  3  is used to substitute for the aforesaid rechargeable battery set  12  such that the rechargeable power supply unit of the automatic vending machine  3  and the solar cell set  11  can be alternatively selected to provide the recognition system  32  with the necessary working voltage. Further, during normal working of the power supply module  1  or when the detected battery voltage is below the predetermined reference voltage value, the microprocessor  21  receives a detection result signal from the voltage detection device  22  and then controls the message indicator light module  27  to give a corresponding visual indication signal, indicating the message of “normal” or “voltage low”. 
     It is to be understood that the above disclosure simply explains an example of the present invention but not intended as a limitation of the spirit of the scope of the invention. The rated voltage of the solar cell set  11  and the rechargeable battery set  12  can be 2.8V, 3.4V, 3.8V or the like. Further, the rated voltage can be changed subject to actual requirements. The voltage range of the solar cell set  11  detectable by the voltage detection device  22  can be within 2.7V˜3.6V. Preferably, the rated voltage can be 3.8V, and the reference voltage value can be 3.6V. When the voltage of the solar cell set  11  is below 3.6V, the solar cell set  11  is stopped from outputting power supply, and the rechargeable battery set  12  is switched on to output power supply. Further, the solar cell set  11  can be comprised of an array of solar cell lamps or solar cell SMDs (Surface Mounted Devices) arranged inside the housing  31  of the automatic vending machine  3  or on the outside of the recognition system  32 . Further, the face panel  311  can be wholly or partially made from transparent or translucent glass or acrylic so that the solar cell set  12  can be radiated by sunlight and convert solar energy into electricity for charging the rechargeable battery set  12  or supplying to the recognition system  32  during the idle mode subject to the control of the power switching module  23 , thereby assuring continuous detection and normal working of the microprocessor  21  and avoiding the automatic vending machine to start up the power supply for merchandise selling operation. Therefore, the invention greatly saves power consumption during the idle mode. 
     A prototype of power-saving solar power supply system for automatic vending machine has been constructed with the features of  FIGS. 1˜4 . The power-saving solar power supply system for automatic vending machine functions smoothly to provide all of the features disclosed earlier. 
     Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.