JP3932799B2 - Vending machine power supply - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power supply device for a vending machine , and more particularly to control technology for an inverter control circuit in a power supply device for a vending machine including an inverter control circuit.
[0002]
[Prior art]
In vending machines for products such as canned juice and tobacco, fluorescent lamps are usually provided for lighting these products. For this reason, the power supply device used in this type of vending machine is provided with an inverter control circuit for performing inverter control of the fluorescent lamp in addition to a DC power supply for supplying power to each part in the vending machine.
[0003]
Specifically, a circuit that can output a stable DC voltage, such as a switching power supply, is used as the DC power supply unit. A direct current voltage is supplied from the direct current power supply unit to each unit in the vending machine (for example, a control circuit constituted by a microcomputer or a direct current load such as a motor).
[0004]
On the other hand, the inverter control circuit is composed of an inverter IC that is circuit independent from the DC power supply unit. Specifically, the inverter IC is configured by a circuit that outputs a switching control signal of a switching element that switches the input voltage of the fluorescent lamp, and the inverter is controlled to turn on / off (turn on / off) the fluorescent lamp. This is performed by a switching control signal output from the IC. That is, when the fluorescent lamp is turned off, the fluorescent lamp is turned off by shutting down a capacitor or a resistor that determines the oscillation frequency of the switching element in the inverter IC.
[0005]
[Problems to be solved by the invention]
However, such a conventional circuit configuration has the following problems and has been desired to be improved.
[0006]
That is, in the above-described conventional power supply device, the fluorescent lamp is turned off by shutting down a capacitor and a resistor that determine the oscillation frequency in the inverter IC. In such a configuration, the fluorescent lamp is turned off (turned off). Even at times, the inverter IC is still operating. Therefore, even when the fluorescent lamp is turned off, power is consumed by the inverter IC, which is not a preferable circuit configuration for energy saving measures.
[0007]
On the other hand, since the DC power supply unit and the inverter control circuit are provided independently, even if the output side of the DC power supply unit is short-circuited, the inverter control circuit is Since the fluorescent lamp operates normally and maintains the lighting state, there is a problem that it is delayed to detect the occurrence of an abnormality in the power supply device.
[0008]
The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide an inverter control circuit for controlling an AC power source supplied to a fluorescent lamp of a vending machine, and the inverter control circuit. in the power supply device for an automatic vending machine comprising a DC power supply having a plurality of power supply output comprising a drive power source, it is possible to suppress the power consumption during off a fluorescent lamp, it may discover abnormal output of the DC power supply unit at an early stage technology Is to provide.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a power supply device for a vending machine according to the present invention includes a plurality of inverter control circuits that control AC power supplied to a fluorescent lamp of the vending machine, and a drive power supply for the inverter control circuit. In the power supply device of the vending machine comprising a DC power supply unit having a power supply output, the DC power supply unit includes a dropper regulator that supplies drive power for the inverter control circuit to a primary side of the transformer, and a secondary of the transformer And a switching power supply circuit having an output terminal for a DC load such as a motor provided in the vending machine and an output terminal for a control circuit constituting a driving power source of a microcomputer in the vending machine. A first control element for controlling energization of an energization line for supplying drive power from the dropper regulator to the inverter control circuit The second control element is provided with a second control terminal that receives an on / off control signal for the fluorescent lamp and a drive power supply from an output terminal for the control circuit of the switching power supply circuit. ON / OFF control is performed by a control element .
[0010]
Here, the inverter control circuit means a control circuit for controlling the on / off speed of the switching element in the inverter circuit, and this inverter control circuit includes an inverter IC in which the control circuit is integrated. to. Further, as the load of the inverter control circuit is intended to mean the load receiving supply of the AC power supply generated by the switching of the switching elements of the inverter circuit (specifically, a fluorescent lamp).
[0011]
That is, according to the first aspect of the invention, the operation control of the load of the inverter control circuit is performed by energization control of the power supply line to the inverter control circuit. That is, in the first aspect of the invention, when the load is to be operated, the power supply line is energized to supply drive power to the inverter control circuit. As a result, the inverter control circuit starts operating, and the switching element performs switching in accordance with this operation, and a predetermined AC power supply is supplied to the load. As a result, the operation of the load is started. On the other hand, when it is desired to stop the operation of the load, the power supply line is cut off and the operation of the inverter control circuit is stopped. In this case, when the operation of the inverter control circuit is stopped, the switching of the switching element is stopped, and no AC power is supplied to the load. As a result, the operation of the load is stopped. Thus, according to the first invention, when the operation of the load is stopped, the power supply to the inverter control circuit is interrupted, so that power is consumed by the inverter control circuit when the load operation is stopped. There is nothing to do.
[0012]
According to a second aspect of the present invention, there is provided a control method for a power supply apparatus, comprising: an inverter control circuit; and a DC power supply unit having a plurality of power supply outputs including a drive power supply for the inverter control circuit. When an output abnormality occurs in the power supply circuit, power supply to a power supply line for supplying drive power to the inverter control circuit is cut off, and supply of power to the load of the inverter control circuit is cut off.
[0013]
That is, in this second invention, when an output abnormality occurs in the power supply circuit other than the inverter control circuit among the power supply outputs of the DC power supply unit, the supply of the drive power to the inverter control circuit is interrupted, Stop the operation of the inverter control circuit load. As a result, when a fluorescent lamp is used as the load of the inverter control circuit, if the output abnormality occurs in the DC power supply unit, the fluorescent lamp is turned off, so that the output abnormality of the DC power supply unit is caused early. Can be found in.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the control method of the power supply device according to the present invention will be described in detail with reference to FIG. 1 and FIG.
[0015]
FIG. 1 is a circuit diagram showing a schematic configuration of a power supply device 1 to which the present invention is applied. More specifically, the power supply device 1 is a power supply device used as a power supply board of a vending machine, The main part is an inverter control circuit 2 for controlling an AC power supply supplied to a fluorescent lamp (not shown) of a vending machine, and a DC power supply unit 3 having a plurality of power supply outputs including a drive power supply for the inverter control circuit 2. Configured as
[0016]
The inverter control circuit 2 is a control circuit that controls the on / off (on / off) speed of switching elements (eg, FETs) of an inverter circuit (not shown). In the illustrated example, the inverter control circuit 2 is in the form of an integrated inverter IC21. The The inverter IC 21 has a first terminal as an input terminal for a drive voltage (drive power source) Vcc, and a fifth signal and a seventh terminal are control signals for performing on / off control of the switching element (switching control). Signal) output terminal. In other words, the switching element is controlled to be turned on / off by the control signals output from the fifth terminal and the seventh terminal, and thereby the AC power supplied to the fluorescent lamp is controlled.
[0017]
On the other hand, the DC power supply unit 3 is a power supply circuit having a plurality of DC outputs, and in the illustrated example, a switching power supply circuit in which the primary side of the transformer 31 is not shown is shown.
[0018]
Specifically, this switching power supply circuit is provided with a dropper regulator having a rectification / smoothing circuit that rectifies and smoothes the commercial power supply to generate a DC power supply on the primary side of the transformer 31 (not shown). Then, the rectified and smoothed DC power supply is used as a DC power supply (eg, DC 140V) switched by the inverter circuit or a drive power supply Vcc for the inverter control circuit 2. In addition, what is shown with the code | symbol VP in the figure has shown the output of this dropper regulator.
[0019]
The DC power generated by the dropper regulator is switched by a switching element (not shown) and taken out to the secondary side via the transformer 31. At that time, DC voltage 24V and 8V are output as output voltages from the output terminals 32 and 33 by setting the turn ratio of the secondary winding of the transformer 31, respectively. That is, on the secondary side of the switching power supply circuit, a rectifying / smoothing circuit including a rectifying diode 41 and a smoothing capacitor 42 for rectifying and smoothing the AC output taken out on the secondary side of the transformer 31 is provided. Thus, a so-called multi-output type power supply is known.
[0020]
In the illustrated example, the output of 24V output from the switching power supply circuit in this way is used as a driving power source for a DC load such as a motor provided in the vending machine, for example. The 8V output is used as a control circuit in the vending machine, specifically, a driving power source for a microcomputer via a DC-DC converter, for example. The output of this switching power supply circuit is indicated by reference sign VS in the figure.
[0021]
The switching power supply circuit shown in FIG. 1 monitors the output voltage on the secondary side of the transformer 31 and controls the oscillation frequency and on-time of a switching element (not shown) of the switching power supply circuit. As a circuit, a feedback control circuit including a programmable shunt regulator 34 having a three-terminal structure and a photocoupler (only a photodiode is illustrated) 35 is provided.
[0022]
Further, reference numeral 36 in the drawing indicates an input terminal for a fluorescent lamp on / off control signal input from a microcomputer outside the drawing. In this embodiment, the input terminal 36 for the on / off control signal is connected to the base terminal (control terminal) of the transistor 37 (second control element) . The emitter terminal of the transistor 37 is connected to the output terminal 33 (VS8 terminal in the figure in an actual circuit) of the DC power supply unit 3, and a voltage of 8V is supplied from the output terminal 33. That is, on / off of the transistor 37 is controlled by Hi / Lo of the on / off control signal.
[0023]
The collector terminal of the transistor 37 is connected to the anode terminal of a photodiode (light emitting element) 38 a constituting the photocoupler 38, and is set so that the photodiode 38 a emits light when the transistor 37 is turned on.
[0024]
The phototransistor (light receiving element) 38b that constitutes the light receiving portion of the photocoupler 38 is disposed so as to control the energization of the energization line that supplies the driving power for the inverter IC21. In other words, the drive power Vcc of the inverter IC21 is supplied from the terminal VP12 when the transistor 39 (first control element) is turned on, and the above-described photopower is supplied to the connection point between the base terminal of the transistor 39 and the cathode terminal of the Zener diode 40. The emitter terminal of the transistor 38b is connected.
[0025]
Accordingly, when the photocoupler 38 is turned on (that is, the phototransistor 38b is turned on), the transistor 39 is turned on and the drive power Vcc is supplied to the inverter IC21. On the other hand, when the photocoupler 38 is off (that is, the phototransistor 38b is off), no current flows through the Zener diode 40, so the transistor 39 is turned off and the supply of the drive power supply Vcc to the inverter IC21 is cut off.
[0026]
The drive power Vcc of the inverter IC 21 supplied from the terminal VP12 is generated on the primary side of the transformer 31 of the switching power circuit. That is, the drive power source Vcc of the inverter IC 21 is generated and supplied from, for example, a DC power source obtained by rectifying and smoothing a commercial power source at a stage before switching by the switching power source circuit.
[0027]
Thus, the control of turning on / off the fluorescent lamp in the power supply apparatus configured as described above will be described with reference to FIG.
[0028]
FIG. 2 is an explanatory diagram showing a part of FIG. 1 in a simplified manner. That is, when the fluorescent lamp is turned on, the input terminal 36 for the on / off control signal is made conductive. Thereby, the transistor 37 is turned on, and accordingly, the photocoupler 38 and the transistor 39 are turned on, and the drive power supply Vcc is supplied to the inverter IC21. As a result, the inverter IC 21 operates, the switching element on / off speed of the inverter circuit (not shown) is controlled, and the fluorescent lamp is turned on.
[0029]
On the other hand, when the fluorescent lamp is turned off, the input terminal 36 for the on / off control signal is opened. As a result, the transistor 37 is turned off, and accordingly, the photocoupler 38 and the transistor 39 are turned off, and the supply of the drive power supply Vcc to the inverter IC21 is cut off. As a result, the operation of the inverter IC 21 stops, the switching element of the inverter circuit (not shown) does not operate, the supply of AC power to the fluorescent lamp is shut off, and the fluorescent lamp is turned off.
[0030]
In this way, in the present invention, the fluorescent lamp is turned on / off by turning on / off the drive power supply Vcc of the inverter IC21. Therefore, when the fluorescent lamp is turned off, the drive power supply Vcc is not supplied to the inverter IC21. Therefore, power is not consumed by the inverter IC 21 while the light is turned off, and the fluorescent lamp can be controlled with power saving. Further, since the drive power Vcc of the inverter IC21 is supplied from the dropper regulator as described above, the noise of the switching power supply circuit does not affect the inverter IC21.
[0031]
In addition, in the present invention, as described above, the transistor 37 disposed on the transmission line for the on / off control signal of the fluorescent lamp is driven by the voltage supplied from the output terminal 33 of the switching power supply circuit. If the output terminals 32 and 33 are short-circuited due to wire catching or the like, resulting in an abnormal output, the output voltages of the output terminals 32 and 33 will drop to almost 0V, thereby turning off the transistor 37.
[0032]
When the transistor 37 is turned off in this manner, the photocoupler 38 is turned off, and the transistor 39 is turned off in the same manner as in the case where the fluorescent lamp is turned off, so that the drive power supply Vcc is supplied to the inverter IC21. Is cut off. That is, when the DC power supply unit 3 falls into an output abnormality, the fluorescent lamp that is the load of the inverter IC 21 is turned off accordingly.
[0033]
Therefore, in the case of the present invention, the fact that the DC power supply unit 3 has experienced an output abnormality (specifically, an output abnormality of a switching power supply circuit other than a dropper regulator that supplies the drive power supply Vcc to the inverter IC21) is extinguished. It can be grasped by (no longer being lit), and an abnormality in the DC power supply unit 3 can be quickly found.
[0034]
The above-described embodiment is merely a preferred embodiment of the present invention, and the present invention is not limited to this, and various design changes can be made within the scope of the invention.
[0035]
For example, in the above-described embodiments, the case where the power supply device 1 is used as a power supply board for a vending machine has been shown. It can also be used as a power supply substrate for the apparatus. Accordingly, the output voltage of the DC power supply unit 3 can be appropriately changed.
[0036]
【The invention's effect】
As described above in detail, according to the power supply device of the vending machine according to the present invention, the switching control of the lighting / extinguishing of the fluorescent lamp controls the energization of the energization line that supplies the driving power from the dropper regulator to the inverter control circuit. Since the first control element is turned on / off , power is not consumed in the inverter control circuit when the fluorescent lamp is turned off , and power saving can be realized.
[0037]
Further, the second control element performs the first control based on the on / off control signal of the fluorescent lamp input to the control terminal and the drive power supplied from the output terminal for the control circuit of the switching power supply circuit. Since the on / off of the element is controlled, if an abnormality occurs in the output for the control circuit of the switching power supply circuit, the power supply to the inverter control circuit is cut off and the fluorescent lamp is turned off. By turning off the light, it is possible to quickly find an abnormality in the output of the DC power supply circuit.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a schematic configuration of a power supply device to which the present invention is applied.
FIG. 2 is an explanatory diagram showing a part of the power supply device;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Power supply device 2 Inverter control circuit 3 DC power supply part 21 Inverter IC
31 Transformer of switching power supply circuit 32, 33 Output terminal 37 Transistor (second control element)
39 Transistor (first control element)
35,38 Photocoupler 40 Zener diode

Claims (1)

In the power supply device of the vending machine comprising an inverter control circuit for controlling the AC power supplied to the fluorescent lamp of the vending machine, and a DC power supply unit having a plurality of power outputs including the drive power of the inverter control circuit,
The DC power supply unit includes a dropper regulator that supplies driving power of the inverter control circuit to a primary side of the transformer, and an output for a DC load such as a motor provided in the vending machine on the secondary side of the transformer. A switching power supply circuit comprising a terminal and an output terminal for a control circuit constituting a driving power supply of a microcomputer in the vending machine;
A first control element that controls the energization of the energization line that supplies drive power to the inverter control circuit from the dropper regulator;
The first control element is controlled by a second control element that receives an on / off control signal for the fluorescent lamp at a control terminal and receives drive power from an output terminal for a control circuit of the switching power supply circuit. ON / OFF controlled
A power supply device for a vending machine.

Images