JPS647425Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a temperature monitoring circuit in a vending machine for refrigerated products such as dairy products.

[Conventional technology]

Generally, this type of vending machine is naturally equipped with a temperature control section that maintains the interior of the product refrigerating chamber at a constant low temperature. However, since this temperature control section is configured independently of the sales control section, sales can be carried out as usual even if an abnormality occurs in the temperature control. In this case, especially in the case of products such as milk and ice cream, even products whose quality has deteriorated due to the rise in temperature are sold. In response to this, a vending machine has been proposed (Utility Model Application Publication No. 7100/1983) that stops selling when the temperature in the refrigerator chamber rises to a predetermined value.

This vending machine will be explained below with reference to FIG.

If the temperature in the product refrigerating chamber is at a temperature suitable for storing the product, the temperature detector 45 is open, and if the product is stored in the refrigerating chamber, the switch 43 is closed. When coins are inserted and the count reaches the selling price, the product sales device 42 operates, opens the switch 42S, and sells one product.
When the sale of the product is completed, the switch 42S is closed for sale by inserting the next coin, but when the switch 42S is opened, the coil 44 is de-energized and the inserted coin is returned during the product sales operation.

When the temperature of the refrigerator compartment increases due to a power outage or the like and reaches the upper limit temperature, the temperature detector 45 closes. Therefore, when the power outage ends, the relay 46 is energized and its operation switches 46A, 46B are switched to contact b, and the fluorescent lamp 4
9 remains off, and the display lamp 48 is lit. Further, the coil 44 is kept de-energized to return the inserted coin, and the relay 46 is self-maintained through the operation switch 46A and the switch 47. Therefore, the lamp 48 indicates the sales discontinued state, and even if the temperature in the refrigerator compartment decreases due to the operation of the refrigeration device and the temperature detector 45 opens, the relay 46 maintains the energized state. Therefore, in order to make it available for sale, switch 47 is required.
This is achieved by opening the relay 46 and releasing the self-holding state of the relay 46. In this manner, after the power is restored, the thawed frozen food is removed and the switch 47 is activated to reset it to a state where it can be sold.

[Problem that the invention attempts to solve]

In this vending machine, when replenishing the product refrigerated compartment, the temperature inside the refrigerated compartment rises and the temperature detector 45
is closed. In this case, even though the product is actually ready for sale once the product replenishment is completed,
Unable to reset the product to a state where it can be sold.
It is necessary to wait until the temperature inside the refrigerator drops and the temperature detector 45 opens.

This invention has a function that stops sales when the temperature in the product refrigerator rises to a set value, and if a predetermined reset operation is performed, sales are possible for a predetermined time t ₁ regardless of the temperature of the product refrigerator. The present invention attempts to provide a temperature monitoring circuit having the following functions.

[Means for solving problems]

The temperature monitoring circuit according to the present invention includes a temperature detection circuit that detects the temperature in the product refrigerator compartment and outputs an abnormality indication signal when the temperature rises to a set value, and a temperature detection circuit that sends out a reset pulse when the power is turned on and resets the product by a reset operation. a reset circuit that sends out a signal; a timer circuit that outputs a clock signal after a predetermined time _t1 after a reset operation is performed by the reset circuit;
After the reset signal arrives from the reset circuit until the clock signal arrives from the timer circuit, a sales signal is sent out regardless of the output of the temperature detection circuit, and after the clock signal arrives, the temperature detection circuit detects an abnormality. It is characterized in that it includes a control circuit that sends out a sales stop signal when the instruction signal is output.

[Effect]

With such a configuration, the present temperature monitoring circuit is able to prevent the temperature of the product by performing a reset operation in the reset circuit even if the temperature inside the product refrigerating compartment rises due to replenishment of products to the product refrigerating compartment and an abnormality indication signal is output from the temperature detection circuit. The control circuit uses the time set by the timer circuit.
Send only the sales signal for t ₁ . The control circuit also operates to send out a sales stop signal when an abnormality instruction signal arrives from the temperature detection circuit after the time _t1 set by the timer circuit has elapsed.

〔Example〕

FIG. 1 is a block configuration diagram of a temperature monitoring circuit according to the present invention, in which a temperature detection circuit 1, a timer circuit 2,
It includes a control circuit 3, a reset circuit 4, and a power failure timer circuit 5. The temperature detection circuit 1 detects the temperature inside the product refrigerating chamber and outputs a signal when the temperature is equal to or higher than a set value _T1 . The timer circuit 2 is reset by a reset pulse or a reset signal output from the reset circuit 4, starts counting time by a signal from the control circuit 3, and outputs a timing signal when a predetermined time _t1 has elapsed. The control circuit 3 receives as input the output of the temperature detection circuit 1, the output of the timer circuit 2, the reset signal of the reset circuit 4, and the output of the timer circuit 5 for power outage.
When the reset circuit 4 performs a reset operation, it outputs a signal that causes the timer circuit 2 to start counting, and also outputs a sales signal and a sales stop signal to the existing product sales control circuit in accordance with the above-mentioned inputs. That is, the control circuit 3 outputs only the sales signal while the timer circuit 2 is counting the time _t1 , and after the timer circuit 2 finishes counting the time _t1 , the control circuit 3 outputs only the sales signal to the temperature detection circuit 1.
When a signal is output from , a sales stop signal is output. The reset circuit 4 outputs a reset pulse to the timer circuit 2 when power is turned on to the temperature monitoring circuit, the cooling device for the product cold room, the product sales control circuit, etc.
When a reset operation is performed, a reset signal is output to the timer circuit 2 and control circuit 3. When a power outage occurs while the control circuit 3 is sending a sales signal, the power outage timer circuit 5 determines whether the power outage time is within a predetermined time _t2 .

Note that, as is well known in the art, the cooling device is controlled by a temperature control section separate from the main temperature monitoring circuit. and,
Immediately after the power is turned on, the temperature in the product refrigerator compartment is sufficiently higher than the set value T ₂ (however, T ₂ < T ₁ ), so continuous operation is performed, and when it drops to the set value T ₂ , the set value T Perform intermittent operation to maintain ₂ .

In the case of a vending machine, the product sales control circuit is a control circuit that includes a so-called coin mechanism, and controls everything from coin insertion to product selection and discharge.

FIG. 2 shows the configuration of FIG. 1 in a concrete circuit diagram. Here, the timer circuit 2 is the pulse generation circuit 2.
A counter 22 that counts pulses from 1 is used to measure time. The power outage timer circuit 5 uses the discharge time constant of the capacitor _C1 to determine the power outage time.
The control circuit 3 outputs a sales signal as "0" and a sales stop signal as "1" to the product sales control circuit.

The operation will be described below with reference to FIG. 3 showing input and output signals of each part of this circuit.

When the power supply V _DD (Fig. 3 A), which is also the power supply for the product sales control circuit and the cooling device, is first turned on, the capacitor C ₁ of the power outage timer circuit 5 is not charged, and the output of the operational amplifier 51 (3 Figure b) is “0”
It is. Further, the counter 22 is reset by a reset pulse generated by the capacitor C ₂ and the resistor R ₉ of the reset circuit 4 when the power supply V _DD is turned on.
The output Q _X (FIG. 3 E) is "0". The "0" signal of the output _Q However, since the other input S, that is, the output of the operational amplifier 51, is "0", the AND circuit 3
The output of 1 (FIG. 3C) is "0". Therefore, the output of the AND circuit 24 (FIG. 3 D) is "0".
Therefore, the output _QX of the counter 22 also remains at "0". At this time, the operation of the cooling system has just started and the temperature in the product refrigerating room is higher than the set value T ₁ , and the output of the operational amplifier 11 of the temperature detection circuit 1 having the thermistor T _h as the temperature detection element (Fig. 3 H) is It is “1”. Therefore, the input S of the AND circuit 33 is also "1". On the other hand, since the output "0" of the AND circuit 31 is converted into a "1" signal by the NOT circuit 32 (see FIG. 3), the input R of the AND circuit 33 is also "1". As a result, the output of the AND circuit 33 (the third
Figure 3) becomes the sales stop signal “1”.

Note that when the sales stop signal "1" is output, the vending machine stops the function of the sales control circuit and displays the sales stop signal.

From this state, when the reset button RB for starting operation in the reset circuit 4 is pressed, the AND circuit 3
Since the input S of 1 becomes "1" and the input R also becomes "1", the output of the AND circuit 31 becomes "1". As a result, a constant periodic pulse from the pulse generating circuit 21 is inputted to the clock input terminal of the counter 22 via the AND circuit 24 (FIG. 3D), and the counter 22 starts counting. The output _QX of this counter 22 becomes "1" when a predetermined count is completed. That is, the counter 22 acts as a timer. The counted value of the counter 22, in other words, the counted time of the timer circuit 2, is set to be longer than the time required for the cooling device to start continuous cooling and drop to the set value _T2 by turning on the power to the cooling device. Note that even if the reset button RB is released for a short time, the AND circuit 31 maintains the output "1" as long as the input R does not change due to the self-holding action of the diode _D2 .

On the other hand, at the same time that the output of the AND circuit 31 becomes "1", the input R of the AND circuit 33 becomes "0".
As a result, the output of the AND circuit 33 becomes the sales signal "0" regardless of the output of the operational amplifier 11, that is, the output of the temperature detection circuit 1, in other words, regardless of the level of temperature in the product refrigerating chamber. This sales signal "0" state means that the timer circuit 2 finishes counting time _t1 and the output _Q
It is maintained until the output becomes "0". That is, even if the operation is started from a state where the temperature in the product refrigerating chamber is sufficiently higher than the set value _T1 , by pressing the reset button RB, it is possible to immediately shift to a state where the product can be sold.

In this way, when the temperature in the refrigerator room drops to the set value _T2 , the cooling device switches to intermittent cooling. Needless to say, in this state, the output of the operational amplifier 11 is "0".

Counter 22 shows time up (for example, 1 hour)
Then, the output Q _X becomes “1” and the AND circuit 3
The output of 1 also becomes "0". The counter 22 holds the output _QX in the "1" state until it is reset. At this time, the input R of the AND circuit 33 also becomes "1", so that the output of the AND circuit 33 is influenced by the output of the operational amplifier 11, that is, the temperature in the refrigerator room. That is, when the temperature inside the refrigerator rises abnormally and reaches the set value _T1 due to a failure of the cooling device or its temperature control unit, the operational amplifier 11
The output becomes “1”. As a result, the output of the AND circuit 33 becomes the sales stop signal "1", and even if the output of the operational amplifier 11 becomes "0" by any chance, there is a self-holding diode _D4 .
The output of the AND circuit 31 is "1", that is, the product cannot be sold unless a reset operation is performed.

Next, when the counter 22 has timed up,
That is, a case will be explained in which the output _QX is "1", the product refrigerating compartment is maintained at the set temperature _T2 by the cooling device, and products are replenished without turning off the power supply _VDD .

At the start of product replenishment, the input S of the AND circuit 31 is "1" and the input R is "0", and the input R of the AND circuit 33 is "1" and the input S is "0".
When _T1 is reached, the input S of the AND circuit 33 becomes "1".
Then, the control circuit 3 outputs a sales stop signal "1". However, after the product replenishment is completed, the reset button
When RB is pressed, the counter 22 is reset by the reset signal via the diode _D6 , and the output _QX
As a result, the AND circuit 3
The output of the timer circuit 2 becomes "1", the timer circuit 2 starts counting the predetermined time _t1 , and the control circuit 3 outputs the sales signal "0".
The subsequent operations are the same as those described above.

In this way, even if the temperature of the product refrigerating compartment unavoidably rises to the set value _T1 due to product replenishment, it is possible to shift to a state where the product can be sold by a reset operation.

In addition to the above-mentioned functions, this circuit also has an additional function provided by a power outage timer circuit 5, which will be explained below.

Assume that the timer circuit 2 starts counting time _t1 by the reset operation and the control circuit 3 outputs a sales signal "0". In this state, the output of the not circuit 52 of the timer circuit 5 (FIG. 3) is "1" and the capacitor _C1 is being charged, so the output of the operational amplifier 51 is "1".

In this state, until the input R of the AND circuit 31 changes, that is, until the output _Q
The sales signal is held at "0" regardless of the output of. However, if a power outage occurs before the temperature in the product refrigerator compartment drops below the set value T ₁ (the output of the operational amplifier 11 becomes "0"), even if the power is restored in a short time, the power outage timer circuit 5 will not work. AND circuit 3
Since the input S of 1 is “0”, the AND circuit 33
Both input R and input S of the input terminal are "1", and a sales stop signal "1" is sent out.

On the other hand, this circuit is equipped with a power outage timer circuit 5, so that the power outage timer circuit 5
If the power outage returns within the set time _t2 , the sales signal "0" can be held at "0" for the newly set time _t1 by the timer circuit 2 without any reset operation when the power outage returns, regardless of the output of the operational amplifier 11. , this will be explained below.

The set value from the start of continuous operation of the cooling device mentioned above.
If a power outage occurs before the voltage drops to T ₁ , recovery occurs within the set time (for example, 10 minutes) required for the voltage to drop to the threshold voltage V _S determined by the time constant of capacitor C ₁ and resistor R ₂ in power outage timer circuit 5. Suppose we did. At the same time as the power is restored, reset circuit 4 is activated as described above.
The counter 22 is reset by the reset pulse from , and the input R of the AND circuit 31 becomes "1". At this time, when the voltage at the non-inverting input terminal of the operational amplifier 51, that is, the discharge voltage of the capacitor _C1 , exceeds the threshold voltage _VS , the output of the operational amplifier 51 becomes "1", as shown in FIG. As a result, the output of the AND circuit 31 is "1" and the output of the counter 2 is "1".
2 counts the clock pulses from the pulse generating circuit 21 again. Also, since the input R of the AND circuit 33 becomes "0", its output becomes the sales signal "0".

As explained above, in this embodiment, when the temperature in the refrigerator compartment of the product rises above the set value T ₁ for some reason, a sales stop signal is sent, and unless a reset operation is performed, the product cannot be sold and there is a risk of deterioration. You can prevent certain products from being sold. Of course, even if sales are suspended, if the temperature rise in the product refrigeration chamber is temporary and the temperature control section immediately operates normally, there is little risk of product deterioration. Therefore,
The user must perform the reset operation after confirming the reason for the suspension of sales and whether or not the product has deteriorated.

Furthermore, taking into account the temperature rise in the product refrigerator when replenishing products, the temperature in the product refrigerator immediately after replenishment is set to the set value T _1.
Even if this is the case, the reset operation sends out the sales signal _t1 for a predetermined period of time, making it possible to sell the product without being affected by the temperature in the refrigerator compartment. Furthermore, if a power outage occurs within this predetermined time and is restored within a short period of time, the sales signal will be automatically sent again for the predetermined time without any reset operation, making it possible to sell products regardless of the temperature inside the refrigerator. I have to.

Further, the present invention is not limited to the circuit configuration shown in FIG. 2, and in particular, the timer circuit 2 and the timer circuit 5 can be realized by means having other timer functions.

[Effect of idea]

As explained above, according to the present invention, the temperature inside the product refrigerated compartment is monitored separately from the temperature control section of the cooling device, and if the temperature rises above a set value, products that are at risk of deterioration are sold. can be stopped. On the other hand, even if the temperature in the product refrigerator compartment rises unavoidably when replenishing products, there is no risk of deterioration of the product due to the continuous cooling operation of the cooling device. It is possible to sell products without any hassle, and it has a great effect in contributing to improving customer service.

Furthermore, if there is a power outage and the power is turned on again within a short period of time when the sales stop signal is being output when no sales are being made, the sales stop signal will be output for a specified period of time even if the internal temperature is within the specified range. Since the product is maintained and sales are suspended until the product reaches a predetermined condition, there is no risk of defective products being sold. Also, the specified time when replenishing the product.
If there is a power outage within t ₂ and the power is restored within a short time,
Another advantage is that a sales signal is automatically sent for a new predetermined time _t1 without a reset operation, making it possible to sell products regardless of whether the refrigeration temperature is high or low.

[Brief explanation of the drawing]

Fig. 1 is a block configuration diagram of the present invention, Fig. 2 is a specific circuit diagram, Fig. 3 is an input/output signal waveform diagram of each part of Fig. 2, and Fig. 4 is a conventional vending machine. FIG. 2 is a circuit diagram of a temperature monitoring circuit. In the figure, 1 is a temperature detection circuit, 2 is a timer circuit, and 3
4 is a control circuit, 4 is a reset circuit, 5 is a power failure timer circuit, 21 is a pulse generation circuit, and 22 is a counter.

Claims (1)

[Scope of utility model registration request] A vending machine for selling refrigerated products such as dairy products has a temperature detection circuit that detects the temperature inside the product refrigerated compartment and outputs an abnormality signal when the temperature rises to a set value, and a reset pulse when the power is turned on. a timer circuit that outputs a clock signal after a predetermined time _t1 after the reset operation is performed by the reset circuit; Until the timing signal arrives from the timer circuit, a sales signal is sent out regardless of the output of the temperature detection circuit, and after the timing signal arrives, when an abnormality instruction signal is output from the temperature detection circuit, a sales stop signal is sent out. and a power outage timer circuit that outputs a signal indicating whether or not the power outage time is within a predetermined time _t2 when a power outage occurs while the control circuit is sending out a sales signal, and the control circuit The temperature monitoring circuit further includes an output of the power outage timer circuit as an input, and holds the sales signal for a predetermined time _t1 when the power outage time is within a predetermined time _t2 .